Risk models with stochastic investment return are widely held in practice, as well as in more challenging research fields. Risk theory is mainly concerned with ruin probability, and a tight bound for ruin ...Risk models with stochastic investment return are widely held in practice, as well as in more challenging research fields. Risk theory is mainly concerned with ruin probability, and a tight bound for ruin probability is the best for practical use. This paper presents a discrete time risk model with stochastic in- vestment return. Conditional expectation properties and martingale inequalities are used to obtain both ex- ponential and non-exponential upper bounds for the ruin probability.展开更多
An ADS （automated dispensing system） was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI （r...An ADS （automated dispensing system） was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI （return on investment）, after seven years of use. ROI was calculated annually （from 2008 to 2015）, by deducting the cost of investment （ADS buying and implementation, maintenance, repairs and ADS upgrade） from the cost saving （drugs stock reduction and decrease of pharmacy staff dedicated to global dispensing）. In 2015, total costs saving （＋$1,141,987） were divided between decreasing drug stock value and reduction of pharmacy staff. Total costs of investment （-$978,656） were acquisition, maintenance, repairs and an unplanned upgrade costs. Finally, the real ROI was ＋$163,331 after seven years of use. In 2008, projected ROI was ＋$410,786. The real payback period has been increased by approximately two years （six years of use, instead of four years as expected）. Despite their cost, ADSs are a worthwhile investment, leading to a ROI within a few years. These economic considerations should be put into perspective with optimization of drugs stock management, greater efficiency of the global dispensing process, securitization of medication process and redeployment of pharmacy staff.展开更多
The key aspect to the successful implementation of BOT concept is the raising of finance by project sponsor,so financial engineering techniques and capital structuring skills are required to find the proper mix of deb...The key aspect to the successful implementation of BOT concept is the raising of finance by project sponsor,so financial engineering techniques and capital structuring skills are required to find the proper mix of debt and equity.The capital structure and present a model to determine the equity level from the aspects of financing scale,construction time and return on investment are analyzed.The resulting model can help the sponsor to avoid the capital risk,and offer the government a criterion to evaluate management ability of the sponsor.To show the application and availability of this model,a case study is conducted.Thus,this paper is concern with the determination of financing scale,construction time,and return on investment which would assist the sponsor to ensure that the equity level for optimal capital structure is available prior to the implementation stage in BOT project operation.展开更多
In order to improve the performance of higher education in the United States, the Goodgrant Foundation intends to donate a total of $100,000,000 (US 100 million) to an appropriate group of schools per year, for five y...In order to improve the performance of higher education in the United States, the Goodgrant Foundation intends to donate a total of $100,000,000 (US 100 million) to an appropriate group of schools per year, for five years, starting in July 2016. For this, our team puts forward upon an optimal investment strategy, which includes the schools to invest, the investment amount of each school, and the return due to investment, to solve this problem. Our main idea is as follows. First of all, we choose suitable investment school universities in the United States. Secondly, we use Analytic Hierarchy Process to get the rate of return on investment and venture capital. Thirdly, we establish a venture capital return model. Finally, solving the mathematical model ensures the investment amount of each school and the return due to investment. To implement this strategy, first of all, we obtain the candidate school based on students score card. Then, according to the factor analysis, we analyze the factors which mainly affect the choice of school. Secondly, we employ Analytic Hierarchy Process to get the rate of return on investment and capital risk. In the end, we establish a risk return model to get investment amount for each school, amount of risk and return. In order to ensure the minimum risk and the maximum return, we set up a multi objective programming model and solve it by using the constraint method. We get the result that includes the maximum net profit of the investment and risk loss rate. According to statistical analysis, we can get the overall return of net income within five years. Finally, we choose 320 candidate schools and get the investment amount of each school according to the principle of as many schools as possible. We have proved that the foundation will receive a return of more than 295.363 million in the next 5 years. After-verification, our strategy can be directly applied to the investment field and get good results.展开更多
At the present stage,each big enterprise bases itself on the human resource inside the enterprise,increases the human capital investment one after another,pays attention to the human capital investment and the talente...At the present stage,each big enterprise bases itself on the human resource inside the enterprise,increases the human capital investment one after another,pays attention to the human capital investment and the talented person education and training.This paper analyzes how the return on human capital investment is realized in the enterprise and how the enterprise realizes the highest return on human capital investment.展开更多
We devise a model for security investment that reflects dynamic interaction between a defender, who faces uncertainty, and an attacker, who repeatedly targets the weakest link. Using the model, we derive and compare o...We devise a model for security investment that reflects dynamic interaction between a defender, who faces uncertainty, and an attacker, who repeatedly targets the weakest link. Using the model, we derive and compare optimal security investment over multiple periods, exploring the delicate balance between proactive and reactive security investment. We show how the best strategy depends on the defender’s knowledge about prospective attacks and the recoverability of costs when upgrading defenses reactively. Our model explains why security under-investment is sometimes rational even when effective defenses are available and can be deployed independently of other parties’ choices. Finally, we connect the model to real-world security problems by examining two case studies where empirical data are available: computers compromised for use in online crime and payment card security.展开更多
The forests of the eastern Democratic Republic of the Congo are among the most biodiverse in the world.They are home to many endangered and endemic species,such as the Grauer’s gorilla(Gorilla beringei graueri).Gover...The forests of the eastern Democratic Republic of the Congo are among the most biodiverse in the world.They are home to many endangered and endemic species,such as the Grauer’s gorilla(Gorilla beringei graueri).Governmentally protected areas(GPAs)in Grauer’s gorilla range face challenges to limit or halt poaching and bushmeat extraction,and it is unclear whether alternative community conservation models can overcome some of these challenges.Here,we examine how protected area(PA)size,conservation models(CM),mode of governance(GM),and the presence of armed groups relate to Return On Investment in land(ROIL)across selected PAs.As proxies of ROIL,we solicited information on the site coverage(area patrolled as a percentage of total surface area)and the level,extent,and trend of poaching or hunting from the[ecosystem or conservation]managers of 11 PA sites to Grauer’s gorillas,of which five were GPAs and six were community based protected areas(CPAs).We found substantial differences in apparent ROIL across PAs.CPA often had higher ROILs than GPA due to the former’s high site coverage,low levels,and decreasing trends in poaching or hunting,and a relatively low presence of armed groups.This suggests that community forests in Grauer’s gorilla range in eastern DRC may have the potential to help address and overcome some of the conservation management challenges currently facing the subspecies.However,follow-up studies are needed to explore the extent to which our findings can be attributed to factors such as the relatively smaller size of community forests,their specific geographical locations,differences in management models or ecosystem attributes(e.g.,the presence of other fauna),or aspects related to the involvement of local communities.展开更多
The Grauer’s gorilla is one of the species most affected by biodiversity degradation,and all the protected areas(PAs)in its range face management challenges(Plumptre et al.,2021).This research examines how the combin...The Grauer’s gorilla is one of the species most affected by biodiversity degradation,and all the protected areas(PAs)in its range face management challenges(Plumptre et al.,2021).This research examines how the combination of rangers’capacity,conservation models,mode of governance,and the presence of armed groups influences the Return On Investment in Rangers(ROIR)for conservation in Grauer’s gorilla range.ROIR is expressed in terms of site coverage rate,the level,extent,and trend of poaching in the PAs.The rangers represent investment.We collected data from 11 PAs in Grauer’s gorilla range.Among the 11 protected areas(PAs),five are governmentally protected areas(GPAs)and six are community-protected areas(CPAs).Due to the small sample size,the analysis focused on descriptive statistics,including means and comparisons of means.Overall,we found that the rangers’density is low in Grauer’s gorilla range(77.05 km^(2) per ranger),which is very low compared to the overall average density of a forest landscape(25 km^(2) per ranger).The rangers’capacity is also low in the Grauer’s gorilla distribution area(22.6 km^(2) per ranger).The rangers’capacity,as well as the ROIR,is influenced by several factors,including the presence of armed groups,conservation models,community engagement,and the holding of weapons by rangers.However,the factors studied in this chapter are not the only ones that influence either rangers’capacity and ROIR.However,the negative impact of armed groups on rangers’capacity ROIR can be alleviated or even aggravated by the local communities’collaboration,not by holding firearms by rangers.In conclusion,community forestry for conservation has a better ROIR overall than Fortress,with the highest site coverage rate,a low level of poaching and hunting,and a decreasing poaching trend,while the extent of poaching is the same in both Fortress and community forestry for conservation.Additionally,ForesCom is more resilient to the presence of armed groups than Fortress.Community forestry for conservation appears to be a viable option for expanding conservation efforts in Grauer’s gorilla range,ensuring its control and combating poaching with a limited number of rangers.展开更多
Nearly all scientists,at conjunction with simplifying a differential equation,have probably used dimensional analysis.Dimensional analysis(also called the Factor-Label Method or the Unit Factor Method)is an approach t...Nearly all scientists,at conjunction with simplifying a differential equation,have probably used dimensional analysis.Dimensional analysis(also called the Factor-Label Method or the Unit Factor Method)is an approach to the problem that uses the fact that one can multiply any number or expression without changing its value.This is a useful technique.However,the reader should take care to understand that chemistry is not simply a mathematics problem.In every physical problem,the result must match the real world.In physics and science,dimensional analysis is a tool to find or check relations among physical quantities by using their dimensions.The dimension of a physical quantity is the combination of the fundamental physical dimensions(usually mass,length,time,electric charge,and temperature)which describe it;for example,speed has the dimension length/time,and may be measured in meters per second,miles per hour,or other units.Dimensional analysis is necessary because a physical law must be independent of the units used to measure the physical variables in order to be general for all cases.One of the most derivation elements from dimensional analysis is scaling and consequently arriving at similarity methods that branch out to two different groups namely self-similarity as the first one,and second kind that through them one can solve the most complex none-linear ODEs(Ordinary Differential Equations)and PDEs(Partial Differential Equations)as well.These equations can be solved either in Eulearian or Lagrangian coordinate systems with their associated BCs(Boundary Conditions)or ICs(Initial Conditions).Exemplary ODEs and PDEs in the form of none-linear can be seen in strong explosives or implosives scenario,where the results can easily be converted to induction of energy in a control forms for a peaceful purpose(i.e.,fission or fusion reactions).展开更多
In Uganda, grain amaranth is relatively new and has generally not been considered as an important crop compared to other grain crops and legumes. This study was therefore conducted to determine factors affecting adopt...In Uganda, grain amaranth is relatively new and has generally not been considered as an important crop compared to other grain crops and legumes. This study was therefore conducted to determine factors affecting adoption of grain amaranth growing, factors affecting production, and economic returns on investment of its production. The study was carried out in Kamuli district where a total of 174 grain amaranth farmers and 90 non-grain amaranth farmers were randomly selected and interviewed. Using descriptive statistics, regression analysis （logit model and a Cobb-Douglas type production function） and profitability ratios, it was found that grain amaranth is produced on a small scale and yields are low. Farmer adoption of the crop was favoured by age, gender （female）, education of the farmer, and source of income. The output was positively affected by the amount of labour and manure used in production, while a negative relationship existed between output and male farmers. The crop was most viable under small acreages （0.02-0.04 ha） with positive returns to investment of 0.016. Its production should therefore be encouraged because of its income generation potential and since it requires small land.展开更多
In accordance to National Commodity Policy （2011-2020）, Malaysian government targets at expending the pepper cultivated area from the current 16,331 ha to 20,110 ha by year 2020. Based on a planting density of 2,000...In accordance to National Commodity Policy （2011-2020）, Malaysian government targets at expending the pepper cultivated area from the current 16,331 ha to 20,110 ha by year 2020. Based on a planting density of 2,000 vines/ha, there will be an urgent need of 7.588 million cuttings for the next five years in order to achieve this target. However, shortages of planting materials, low productivity and occurrence of pests and diseases remain as the major challenge of pepper industry nowadays. Therefore, a novel farming innovation, namely W-configuration cultivation method has been developed to ensure high production of planting materials for large-scale pepper cultivation and at the same time to maximize land use in pepper farm. A field evaluation was conducted to compare the cutting production among W-configuration, V-configuration and traditional cultivation method. W-configuration recorded the highest mean number of pepper cuttings produced with 11.97 cuttings per vine in every pruning cycle, or equivalent to 71% of increment as compared to 7.00 cuttings per vine produced from the traditional planting method. Meanwhile, V-configuration produced 8.91 of mean cuttings, which are significantly lower than those produced by W-configuration method and yet comparable to traditional method. Based on return on investment （ROI） analysis, implementation of W-configuration cultivation method was able to achieve 35% of return per cycle of planting within two years for the first cycle and upsurged to approximately 355% for the subsequence cycle. Furthermore, this novel innovation also out-yielded traditional planting method by 75.27% for the first and second year of green berry production. The ROI analysis proved the feasibility of this newly developed cultivation method to create potential new income for pepper smallholders in Malaysia, who traditionally cultivate pepper for its peppercorn production. This study also enlightened the thorough planting procedures of W-configuration cultivation method mainly for pepper cutting production.展开更多
A high quality transportation system is necessary in a modem economy, and a road network is a common and significant, component of the system. Road systems have two major objectives： to enable the movement of passeng...A high quality transportation system is necessary in a modem economy, and a road network is a common and significant, component of the system. Road systems have two major objectives： to enable the movement of passenger vehicles and the movement of freight vehicles at reasonable speeds. An important part of the transportation system and an expensive investment, a functional road network must meet both objectives to main- tain an efficient economy. In Australia, the Department of Infrastructure and Regional Development reported that, in 2011/12, the total road length was approximately 900,000 kin, and the total road expenditure was approximately $19 billion. Good policy requires that infrastructure investments provide a return on investment, thus warranting judicious management to ensure that it is maintained in a cost effective manner. Recent studies in Queensland, Australia, have identified differences between financial and engi- neering professionals in their understanding of infrastructure depreciation, condition deterioration, and future funding needs. Furthermore, the Queensland Asset Sustainability Ratio （ASR） requires clearer definitions to ensure that infrastructure remains meaningful to all users. This study proposes a separate sustainability index for road pavements （SIR） unlike the ASR that combines all type of assets. The justification is our ability to assess road condition, the high value of road assets, relative value to other infrastructure, and advanced knowledge of deterioration relative to other infrastructure. The SIR involves community consultation to target an average pavement condition index （PCI）. This study also provides an alternative method to determine the optimal target PCI for a local展开更多
The development of pension finance is of great significance to China. first of all, the development of pension finance is conducive to improving China＇s multi-level and multi-pillar pension system, promote the sustai...The development of pension finance is of great significance to China. first of all, the development of pension finance is conducive to improving China＇s multi-level and multi-pillar pension system, promote the sustainable development of the social security system; secondly, the development of pension finance will create a new ＂blue ocean＂ in the financial markets, which is conducive to the improvement of China＇s financial system and capital market;finally, the development of pension finance will help supply-side reforms,which is conducive to the healthy development of the national economy of china. But now there are many difficulties： first, the top-design of China＇s social security system is not perfect; secondly, the current development model of pension finance in China is unclear, the return on investment mechanism is not perfect, the attractiveness of these projects needs to be improved; finally, under the background of Interact finance, mixed supervision is imminent. Therefore, under the new economic conditions must be structured from the supply side of the reform, the development of pension funds to seek the right ideas.展开更多
In the 1970s,scientists began experimenting with powerful laser beams to compress and heat the hydrogen isotopes to the point of fusion,a technique called ICF(Inertial Confinement Fusion).In the“direct drive”approac...In the 1970s,scientists began experimenting with powerful laser beams to compress and heat the hydrogen isotopes to the point of fusion,a technique called ICF(Inertial Confinement Fusion).In the“direct drive”approach to ICF,powerful beams of laser light are focused on a small spherical pellet containing micrograms of deuterium and tritium.The rapid heating caused by the laser“driver”makes the outer layer of the target explode.In keeping with Isaac Newton’s Third Law“For every action,there is an equal and opposite reaction”,the remaining portion of the target is driven inwards in a rocket-like implosion,causing compression of the fuel inside the capsule and the formation of a shock wave,which further heats the fuel in the very center and results in a self-sustaining burn.The fusion burn propagates outward through the cooler,outer regions of the capsule much more rapidly than the capsule can expand.Instead of magnetic fields,the plasma is confined by the inertia of its own mass—hence the term inertial confinement fusion.A similar process can be observed on an astrophysical scale in stars and the terrestrial uber world,that have exhausted their nuclear fuel,hence inertially or gravitationally collapsing and generating a supernova explosion,where the results can easily be converted to induction of energy in control forms for a peaceful purpose(i.e.,inertial fusion reaction)by means of thermal physics and statistical mechanics behavior of an ideal Fermi gas,utilizing Fermi-Degeneracy and Thomas-Fermi theory.The fundamental understanding of thermal physics and statistical mechanics enables us to have a better understanding of Fermi-Degeneracy as well as Thomas-Fermi theory of ideal gas,which results in laser compressing matter to a super high density for purpose of producing thermonuclear energy in way of controlled form for peaceful shape and form i.e.CTR(Controlled Thermonuclear Reaction).In this short review,we have concentrated on Fundamental of State Equations by driving them as it was evaluated in book Statistical Mechanics written by Mayer,J.and Mayer,M.in this article.展开更多
It is a safe and environmentally-friendly method to exploit natural gas hydrates(“hydrate”)by using flue gas(mainly including CO_(2)and N_(2))from electric power plants.So far,however,its energy consumption and ener...It is a safe and environmentally-friendly method to exploit natural gas hydrates(“hydrate”)by using flue gas(mainly including CO_(2)and N_(2))from electric power plants.So far,however,its energy consumption and energy efficiency has not been investigated thoroughly.In this paper,the process to exploit hydrates from flue gas was established.Firstly,flue gas is injected into hydrate reservoirs after it is pressurized.The hydrates in reservoirs partially experience thermal decomposition while the rest is replaced with flue gas,so CH_(4)-CO_(2)-N_(2)mixture is formed.Secondly,the concentrated CH_(4)-CO_(2)mixture is got after N_(2)is separated and removed by using membrane component.And thirdly,the CH_(4)eCO_(2)mixture is delivered to the original electric power plant.This process was simulated by using the software Aspen Plus to analyze the production/injection ratio in the process of flue gas replacement under different injection pressures,the methane replacement ratio,and the energy consumption and energy efficiency in the whole process.It is indicated that the energy in the process of hydrate exploitation from flue gas is mainly consumed at the pressurized injection stage,and the injection pressure increase correspondingly results in the increase of energy consumption at pressurization and membrane separation stages,and to some extent improves the recovery ratio of pressure energy.Besides,when the injection pressure is 5e16 MPa,the production/injection ratio in the process of flue gas replacement is 0.03-0.26,the methane replacement ratio is 19.9-56.2%,the unit energy consumption in the whole process is 2.15-1.05(kW$h)/kgCH_(4),and the energy return on investment(EROI)is 7.2-14.7.It is concluded that the energy efficiency of hydrate exploitation from flue gas can be effectively improved by increasing the injection pressure in the range of 5e10 MPa.展开更多
This study aimed to evaluate the Lithothamnium organic mineral in the diets of Penaeus vannamei in low-salinity water with a synbiotic system.Two diets were formulated by partially replacing inorganic minerals(calcium...This study aimed to evaluate the Lithothamnium organic mineral in the diets of Penaeus vannamei in low-salinity water with a synbiotic system.Two diets were formulated by partially replacing inorganic minerals(calcium,magnesium,and potassium)with a commercial source of Lithothamnium at levels of 2%(LT2)and 4%(LT4)per kg of diet,and two more diets were prepared using the same levels:2%(CTLT2)and 4%(CTLT4)of Lithothamnium per kg of diet,fixed onto the pellets using a commercial binder.The experiment was conducted for 50 days with a stocking density of 50 shrimps(3.1 g)per m^(2)in a low-water salinity synbiotic system.Different doses and application forms affected the activities of digestive enzymes(trypsin,chymotrypsin,leucine aminopeptidase,amylase,and lipase)in the shrimp hepatopancreas.The oxidative stress enzymes did not differ significantly between the times analyzed,but MDA at 25 days of culture showed different values between LT2 and LT4 treatments compared to CTLT4.The shrimp’s proximate and mineral composition showed that the concentration of lipids was lower in the CTLT2 and CTLT4 treatments,while the concentration of calcium was higher in the CTLT4 treatment.The LT2 treatment has a significant difference in shrimp performance(final weight,weekly growth,yield,and FCR)and a higher return on investment(34.26)compared to the other treatments and the control.Based on these results,the Lithothamnium organic mineral addition in diets for Penaeus vannamei for optimal growth was 2%addition(LT2)in the shrimp feed.展开更多
This article examines, from a dynamicperspective, thegeneralsituation ofthedevelopment oftheSouth Korean directinvestmentinChina since1992when thetwocountriesestablished diplomaticrelations.It probesinto manycharacter...This article examines, from a dynamicperspective, thegeneralsituation ofthedevelopment oftheSouth Korean directinvestmentinChina since1992when thetwocountriesestablished diplomaticrelations.It probesinto manycharacteristicsoftheSouth Korean directinvestment in China: itslatestartyetrapid rise, the smaller averagevalueofKorean project investments, the accelerated process of localization by large South Korean enterprises in China, the diversified industrial distribution, and the wide-ranging geographical layout. It analyses reasonsforthe rapid increase in South Koreaninvestment in China:theuse of China’slow- priced production factors, the South Korean enterprises’ direct entry into the Chinese market, and the stable investment environment with fewer labour disputes that China provides. This article finally also proves that South Korean enterprises have achieved satisfactory results from their direct investment in China.展开更多
Consumption is the foundation of economic development.Currently,in sufficient domestic demand,particularly sluggish consumption,has emerged as a prominent challenge in the operation of China's economy.Moreover,the...Consumption is the foundation of economic development.Currently,in sufficient domestic demand,particularly sluggish consumption,has emerged as a prominent challenge in the operation of China's economy.Moreover,the external environment has become increasingly complex and severe.In response to these challenges,both the Central Economic Work Conference last year and this year's Report on the Work of the Government have underscored the imperative of vigorously boosting consumption and investment returns and stimulating domestic demand.Boosting consumption has now become the top priority in advancing China's current economic initiatives.展开更多
In this paper, the optimal trading strategy in timing the market by switching between two stocks is given. In order to deal with a large sample size with a fast turnaround computation time, we propose a class of recur...In this paper, the optimal trading strategy in timing the market by switching between two stocks is given. In order to deal with a large sample size with a fast turnaround computation time, we propose a class of recursive algorithm. A simulation is given to verify the effectiveness of our method.展开更多
基金Supported by the National Natural Science Foundation of China (Nos. 19831020 and 70003002) and the Fundamental Research Foundation of School of Economics and Management,Tsinghua University
文摘Risk models with stochastic investment return are widely held in practice, as well as in more challenging research fields. Risk theory is mainly concerned with ruin probability, and a tight bound for ruin probability is the best for practical use. This paper presents a discrete time risk model with stochastic in- vestment return. Conditional expectation properties and martingale inequalities are used to obtain both ex- ponential and non-exponential upper bounds for the ruin probability.
文摘An ADS （automated dispensing system） was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI （return on investment）, after seven years of use. ROI was calculated annually （from 2008 to 2015）, by deducting the cost of investment （ADS buying and implementation, maintenance, repairs and ADS upgrade） from the cost saving （drugs stock reduction and decrease of pharmacy staff dedicated to global dispensing）. In 2015, total costs saving （＋$1,141,987） were divided between decreasing drug stock value and reduction of pharmacy staff. Total costs of investment （-$978,656） were acquisition, maintenance, repairs and an unplanned upgrade costs. Finally, the real ROI was ＋$163,331 after seven years of use. In 2008, projected ROI was ＋$410,786. The real payback period has been increased by approximately two years （six years of use, instead of four years as expected）. Despite their cost, ADSs are a worthwhile investment, leading to a ROI within a few years. These economic considerations should be put into perspective with optimization of drugs stock management, greater efficiency of the global dispensing process, securitization of medication process and redeployment of pharmacy staff.
文摘The key aspect to the successful implementation of BOT concept is the raising of finance by project sponsor,so financial engineering techniques and capital structuring skills are required to find the proper mix of debt and equity.The capital structure and present a model to determine the equity level from the aspects of financing scale,construction time and return on investment are analyzed.The resulting model can help the sponsor to avoid the capital risk,and offer the government a criterion to evaluate management ability of the sponsor.To show the application and availability of this model,a case study is conducted.Thus,this paper is concern with the determination of financing scale,construction time,and return on investment which would assist the sponsor to ensure that the equity level for optimal capital structure is available prior to the implementation stage in BOT project operation.
文摘In order to improve the performance of higher education in the United States, the Goodgrant Foundation intends to donate a total of $100,000,000 (US 100 million) to an appropriate group of schools per year, for five years, starting in July 2016. For this, our team puts forward upon an optimal investment strategy, which includes the schools to invest, the investment amount of each school, and the return due to investment, to solve this problem. Our main idea is as follows. First of all, we choose suitable investment school universities in the United States. Secondly, we use Analytic Hierarchy Process to get the rate of return on investment and venture capital. Thirdly, we establish a venture capital return model. Finally, solving the mathematical model ensures the investment amount of each school and the return due to investment. To implement this strategy, first of all, we obtain the candidate school based on students score card. Then, according to the factor analysis, we analyze the factors which mainly affect the choice of school. Secondly, we employ Analytic Hierarchy Process to get the rate of return on investment and capital risk. In the end, we establish a risk return model to get investment amount for each school, amount of risk and return. In order to ensure the minimum risk and the maximum return, we set up a multi objective programming model and solve it by using the constraint method. We get the result that includes the maximum net profit of the investment and risk loss rate. According to statistical analysis, we can get the overall return of net income within five years. Finally, we choose 320 candidate schools and get the investment amount of each school according to the principle of as many schools as possible. We have proved that the foundation will receive a return of more than 295.363 million in the next 5 years. After-verification, our strategy can be directly applied to the investment field and get good results.
文摘At the present stage,each big enterprise bases itself on the human resource inside the enterprise,increases the human capital investment one after another,pays attention to the human capital investment and the talented person education and training.This paper analyzes how the return on human capital investment is realized in the enterprise and how the enterprise realizes the highest return on human capital investment.
文摘We devise a model for security investment that reflects dynamic interaction between a defender, who faces uncertainty, and an attacker, who repeatedly targets the weakest link. Using the model, we derive and compare optimal security investment over multiple periods, exploring the delicate balance between proactive and reactive security investment. We show how the best strategy depends on the defender’s knowledge about prospective attacks and the recoverability of costs when upgrading defenses reactively. Our model explains why security under-investment is sometimes rational even when effective defenses are available and can be deployed independently of other parties’ choices. Finally, we connect the model to real-world security problems by examining two case studies where empirical data are available: computers compromised for use in online crime and payment card security.
文摘The forests of the eastern Democratic Republic of the Congo are among the most biodiverse in the world.They are home to many endangered and endemic species,such as the Grauer’s gorilla(Gorilla beringei graueri).Governmentally protected areas(GPAs)in Grauer’s gorilla range face challenges to limit or halt poaching and bushmeat extraction,and it is unclear whether alternative community conservation models can overcome some of these challenges.Here,we examine how protected area(PA)size,conservation models(CM),mode of governance(GM),and the presence of armed groups relate to Return On Investment in land(ROIL)across selected PAs.As proxies of ROIL,we solicited information on the site coverage(area patrolled as a percentage of total surface area)and the level,extent,and trend of poaching or hunting from the[ecosystem or conservation]managers of 11 PA sites to Grauer’s gorillas,of which five were GPAs and six were community based protected areas(CPAs).We found substantial differences in apparent ROIL across PAs.CPA often had higher ROILs than GPA due to the former’s high site coverage,low levels,and decreasing trends in poaching or hunting,and a relatively low presence of armed groups.This suggests that community forests in Grauer’s gorilla range in eastern DRC may have the potential to help address and overcome some of the conservation management challenges currently facing the subspecies.However,follow-up studies are needed to explore the extent to which our findings can be attributed to factors such as the relatively smaller size of community forests,their specific geographical locations,differences in management models or ecosystem attributes(e.g.,the presence of other fauna),or aspects related to the involvement of local communities.
文摘The Grauer’s gorilla is one of the species most affected by biodiversity degradation,and all the protected areas(PAs)in its range face management challenges(Plumptre et al.,2021).This research examines how the combination of rangers’capacity,conservation models,mode of governance,and the presence of armed groups influences the Return On Investment in Rangers(ROIR)for conservation in Grauer’s gorilla range.ROIR is expressed in terms of site coverage rate,the level,extent,and trend of poaching in the PAs.The rangers represent investment.We collected data from 11 PAs in Grauer’s gorilla range.Among the 11 protected areas(PAs),five are governmentally protected areas(GPAs)and six are community-protected areas(CPAs).Due to the small sample size,the analysis focused on descriptive statistics,including means and comparisons of means.Overall,we found that the rangers’density is low in Grauer’s gorilla range(77.05 km^(2) per ranger),which is very low compared to the overall average density of a forest landscape(25 km^(2) per ranger).The rangers’capacity is also low in the Grauer’s gorilla distribution area(22.6 km^(2) per ranger).The rangers’capacity,as well as the ROIR,is influenced by several factors,including the presence of armed groups,conservation models,community engagement,and the holding of weapons by rangers.However,the factors studied in this chapter are not the only ones that influence either rangers’capacity and ROIR.However,the negative impact of armed groups on rangers’capacity ROIR can be alleviated or even aggravated by the local communities’collaboration,not by holding firearms by rangers.In conclusion,community forestry for conservation has a better ROIR overall than Fortress,with the highest site coverage rate,a low level of poaching and hunting,and a decreasing poaching trend,while the extent of poaching is the same in both Fortress and community forestry for conservation.Additionally,ForesCom is more resilient to the presence of armed groups than Fortress.Community forestry for conservation appears to be a viable option for expanding conservation efforts in Grauer’s gorilla range,ensuring its control and combating poaching with a limited number of rangers.
文摘Nearly all scientists,at conjunction with simplifying a differential equation,have probably used dimensional analysis.Dimensional analysis(also called the Factor-Label Method or the Unit Factor Method)is an approach to the problem that uses the fact that one can multiply any number or expression without changing its value.This is a useful technique.However,the reader should take care to understand that chemistry is not simply a mathematics problem.In every physical problem,the result must match the real world.In physics and science,dimensional analysis is a tool to find or check relations among physical quantities by using their dimensions.The dimension of a physical quantity is the combination of the fundamental physical dimensions(usually mass,length,time,electric charge,and temperature)which describe it;for example,speed has the dimension length/time,and may be measured in meters per second,miles per hour,or other units.Dimensional analysis is necessary because a physical law must be independent of the units used to measure the physical variables in order to be general for all cases.One of the most derivation elements from dimensional analysis is scaling and consequently arriving at similarity methods that branch out to two different groups namely self-similarity as the first one,and second kind that through them one can solve the most complex none-linear ODEs(Ordinary Differential Equations)and PDEs(Partial Differential Equations)as well.These equations can be solved either in Eulearian or Lagrangian coordinate systems with their associated BCs(Boundary Conditions)or ICs(Initial Conditions).Exemplary ODEs and PDEs in the form of none-linear can be seen in strong explosives or implosives scenario,where the results can easily be converted to induction of energy in a control forms for a peaceful purpose(i.e.,fission or fusion reactions).
文摘In Uganda, grain amaranth is relatively new and has generally not been considered as an important crop compared to other grain crops and legumes. This study was therefore conducted to determine factors affecting adoption of grain amaranth growing, factors affecting production, and economic returns on investment of its production. The study was carried out in Kamuli district where a total of 174 grain amaranth farmers and 90 non-grain amaranth farmers were randomly selected and interviewed. Using descriptive statistics, regression analysis （logit model and a Cobb-Douglas type production function） and profitability ratios, it was found that grain amaranth is produced on a small scale and yields are low. Farmer adoption of the crop was favoured by age, gender （female）, education of the farmer, and source of income. The output was positively affected by the amount of labour and manure used in production, while a negative relationship existed between output and male farmers. The crop was most viable under small acreages （0.02-0.04 ha） with positive returns to investment of 0.016. Its production should therefore be encouraged because of its income generation potential and since it requires small land.
文摘In accordance to National Commodity Policy （2011-2020）, Malaysian government targets at expending the pepper cultivated area from the current 16,331 ha to 20,110 ha by year 2020. Based on a planting density of 2,000 vines/ha, there will be an urgent need of 7.588 million cuttings for the next five years in order to achieve this target. However, shortages of planting materials, low productivity and occurrence of pests and diseases remain as the major challenge of pepper industry nowadays. Therefore, a novel farming innovation, namely W-configuration cultivation method has been developed to ensure high production of planting materials for large-scale pepper cultivation and at the same time to maximize land use in pepper farm. A field evaluation was conducted to compare the cutting production among W-configuration, V-configuration and traditional cultivation method. W-configuration recorded the highest mean number of pepper cuttings produced with 11.97 cuttings per vine in every pruning cycle, or equivalent to 71% of increment as compared to 7.00 cuttings per vine produced from the traditional planting method. Meanwhile, V-configuration produced 8.91 of mean cuttings, which are significantly lower than those produced by W-configuration method and yet comparable to traditional method. Based on return on investment （ROI） analysis, implementation of W-configuration cultivation method was able to achieve 35% of return per cycle of planting within two years for the first cycle and upsurged to approximately 355% for the subsequence cycle. Furthermore, this novel innovation also out-yielded traditional planting method by 75.27% for the first and second year of green berry production. The ROI analysis proved the feasibility of this newly developed cultivation method to create potential new income for pepper smallholders in Malaysia, who traditionally cultivate pepper for its peppercorn production. This study also enlightened the thorough planting procedures of W-configuration cultivation method mainly for pepper cutting production.
文摘A high quality transportation system is necessary in a modem economy, and a road network is a common and significant, component of the system. Road systems have two major objectives： to enable the movement of passenger vehicles and the movement of freight vehicles at reasonable speeds. An important part of the transportation system and an expensive investment, a functional road network must meet both objectives to main- tain an efficient economy. In Australia, the Department of Infrastructure and Regional Development reported that, in 2011/12, the total road length was approximately 900,000 kin, and the total road expenditure was approximately $19 billion. Good policy requires that infrastructure investments provide a return on investment, thus warranting judicious management to ensure that it is maintained in a cost effective manner. Recent studies in Queensland, Australia, have identified differences between financial and engi- neering professionals in their understanding of infrastructure depreciation, condition deterioration, and future funding needs. Furthermore, the Queensland Asset Sustainability Ratio （ASR） requires clearer definitions to ensure that infrastructure remains meaningful to all users. This study proposes a separate sustainability index for road pavements （SIR） unlike the ASR that combines all type of assets. The justification is our ability to assess road condition, the high value of road assets, relative value to other infrastructure, and advanced knowledge of deterioration relative to other infrastructure. The SIR involves community consultation to target an average pavement condition index （PCI）. This study also provides an alternative method to determine the optimal target PCI for a local
文摘The development of pension finance is of great significance to China. first of all, the development of pension finance is conducive to improving China＇s multi-level and multi-pillar pension system, promote the sustainable development of the social security system; secondly, the development of pension finance will create a new ＂blue ocean＂ in the financial markets, which is conducive to the improvement of China＇s financial system and capital market;finally, the development of pension finance will help supply-side reforms,which is conducive to the healthy development of the national economy of china. But now there are many difficulties： first, the top-design of China＇s social security system is not perfect; secondly, the current development model of pension finance in China is unclear, the return on investment mechanism is not perfect, the attractiveness of these projects needs to be improved; finally, under the background of Interact finance, mixed supervision is imminent. Therefore, under the new economic conditions must be structured from the supply side of the reform, the development of pension funds to seek the right ideas.
文摘In the 1970s,scientists began experimenting with powerful laser beams to compress and heat the hydrogen isotopes to the point of fusion,a technique called ICF(Inertial Confinement Fusion).In the“direct drive”approach to ICF,powerful beams of laser light are focused on a small spherical pellet containing micrograms of deuterium and tritium.The rapid heating caused by the laser“driver”makes the outer layer of the target explode.In keeping with Isaac Newton’s Third Law“For every action,there is an equal and opposite reaction”,the remaining portion of the target is driven inwards in a rocket-like implosion,causing compression of the fuel inside the capsule and the formation of a shock wave,which further heats the fuel in the very center and results in a self-sustaining burn.The fusion burn propagates outward through the cooler,outer regions of the capsule much more rapidly than the capsule can expand.Instead of magnetic fields,the plasma is confined by the inertia of its own mass—hence the term inertial confinement fusion.A similar process can be observed on an astrophysical scale in stars and the terrestrial uber world,that have exhausted their nuclear fuel,hence inertially or gravitationally collapsing and generating a supernova explosion,where the results can easily be converted to induction of energy in control forms for a peaceful purpose(i.e.,inertial fusion reaction)by means of thermal physics and statistical mechanics behavior of an ideal Fermi gas,utilizing Fermi-Degeneracy and Thomas-Fermi theory.The fundamental understanding of thermal physics and statistical mechanics enables us to have a better understanding of Fermi-Degeneracy as well as Thomas-Fermi theory of ideal gas,which results in laser compressing matter to a super high density for purpose of producing thermonuclear energy in way of controlled form for peaceful shape and form i.e.CTR(Controlled Thermonuclear Reaction).In this short review,we have concentrated on Fundamental of State Equations by driving them as it was evaluated in book Statistical Mechanics written by Mayer,J.and Mayer,M.in this article.
文摘It is a safe and environmentally-friendly method to exploit natural gas hydrates(“hydrate”)by using flue gas(mainly including CO_(2)and N_(2))from electric power plants.So far,however,its energy consumption and energy efficiency has not been investigated thoroughly.In this paper,the process to exploit hydrates from flue gas was established.Firstly,flue gas is injected into hydrate reservoirs after it is pressurized.The hydrates in reservoirs partially experience thermal decomposition while the rest is replaced with flue gas,so CH_(4)-CO_(2)-N_(2)mixture is formed.Secondly,the concentrated CH_(4)-CO_(2)mixture is got after N_(2)is separated and removed by using membrane component.And thirdly,the CH_(4)eCO_(2)mixture is delivered to the original electric power plant.This process was simulated by using the software Aspen Plus to analyze the production/injection ratio in the process of flue gas replacement under different injection pressures,the methane replacement ratio,and the energy consumption and energy efficiency in the whole process.It is indicated that the energy in the process of hydrate exploitation from flue gas is mainly consumed at the pressurized injection stage,and the injection pressure increase correspondingly results in the increase of energy consumption at pressurization and membrane separation stages,and to some extent improves the recovery ratio of pressure energy.Besides,when the injection pressure is 5e16 MPa,the production/injection ratio in the process of flue gas replacement is 0.03-0.26,the methane replacement ratio is 19.9-56.2%,the unit energy consumption in the whole process is 2.15-1.05(kW$h)/kgCH_(4),and the energy return on investment(EROI)is 7.2-14.7.It is concluded that the energy efficiency of hydrate exploitation from flue gas can be effectively improved by increasing the injection pressure in the range of 5e10 MPa.
基金supported by the Pernambuco Science and Technology Support Foundation(FACEPE)for the scholarships granted(process number IBPG-0035-5.04/22)Coordination for the Improvement of Higher Education Personnel(CAPES)for the scholarships granted(process number 88887.703420/2022-0 and Financing Code 001)+1 种基金National Council for Scientific and Technological Development(CNPq)by provided a grant to Roberta Borda Soares(PQ 309176/2022-0)Silvio Peixoto(PQ 303893/2019-2)and Luis Otavio Brito(PQ 309669/2021-9)and Fertimar Mineração e Navegação S.A.(Primasea).
文摘This study aimed to evaluate the Lithothamnium organic mineral in the diets of Penaeus vannamei in low-salinity water with a synbiotic system.Two diets were formulated by partially replacing inorganic minerals(calcium,magnesium,and potassium)with a commercial source of Lithothamnium at levels of 2%(LT2)and 4%(LT4)per kg of diet,and two more diets were prepared using the same levels:2%(CTLT2)and 4%(CTLT4)of Lithothamnium per kg of diet,fixed onto the pellets using a commercial binder.The experiment was conducted for 50 days with a stocking density of 50 shrimps(3.1 g)per m^(2)in a low-water salinity synbiotic system.Different doses and application forms affected the activities of digestive enzymes(trypsin,chymotrypsin,leucine aminopeptidase,amylase,and lipase)in the shrimp hepatopancreas.The oxidative stress enzymes did not differ significantly between the times analyzed,but MDA at 25 days of culture showed different values between LT2 and LT4 treatments compared to CTLT4.The shrimp’s proximate and mineral composition showed that the concentration of lipids was lower in the CTLT2 and CTLT4 treatments,while the concentration of calcium was higher in the CTLT4 treatment.The LT2 treatment has a significant difference in shrimp performance(final weight,weekly growth,yield,and FCR)and a higher return on investment(34.26)compared to the other treatments and the control.Based on these results,the Lithothamnium organic mineral addition in diets for Penaeus vannamei for optimal growth was 2%addition(LT2)in the shrimp feed.
文摘This article examines, from a dynamicperspective, thegeneralsituation ofthedevelopment oftheSouth Korean directinvestmentinChina since1992when thetwocountriesestablished diplomaticrelations.It probesinto manycharacteristicsoftheSouth Korean directinvestment in China: itslatestartyetrapid rise, the smaller averagevalueofKorean project investments, the accelerated process of localization by large South Korean enterprises in China, the diversified industrial distribution, and the wide-ranging geographical layout. It analyses reasonsforthe rapid increase in South Koreaninvestment in China:theuse of China’slow- priced production factors, the South Korean enterprises’ direct entry into the Chinese market, and the stable investment environment with fewer labour disputes that China provides. This article finally also proves that South Korean enterprises have achieved satisfactory results from their direct investment in China.
文摘Consumption is the foundation of economic development.Currently,in sufficient domestic demand,particularly sluggish consumption,has emerged as a prominent challenge in the operation of China's economy.Moreover,the external environment has become increasingly complex and severe.In response to these challenges,both the Central Economic Work Conference last year and this year's Report on the Work of the Government have underscored the imperative of vigorously boosting consumption and investment returns and stimulating domestic demand.Boosting consumption has now become the top priority in advancing China's current economic initiatives.
基金Supported by the Research Fund for the Doctoral Program of Higher Education of China (Grant No.20020269003)
文摘In this paper, the optimal trading strategy in timing the market by switching between two stocks is given. In order to deal with a large sample size with a fast turnaround computation time, we propose a class of recursive algorithm. A simulation is given to verify the effectiveness of our method.
