BACKGROUND Lisfranc injuries have not received much attention by orthopedic doctors in the past,and there is little related research on the diagnosis and treatment of these injuries.In recent years with the rise in fo...BACKGROUND Lisfranc injuries have not received much attention by orthopedic doctors in the past,and there is little related research on the diagnosis and treatment of these injuries.In recent years with the rise in foot and ankle surgery,doctors are now paying more attention to this type of injury.However,there is still a high rate of missed diagnosis due to insufficient attention causing treatment delays or inadequate treatments,which eventually result in greater sequelae;including long-term pain,arthritis,foot deformity etc.In particular,for cases with a mild Lisfranc joint complex injury,the incidence of sequelae is higher.AIM To select an active surgical treatment for an atypical Lisfranc joint complex injury and to evaluate the clinical efficacy of the surgical treatment.METHODS The clinical data of 18 patients,including 10 males and 8 females aged 20-64 years with Lisfranc injuries treated in our department from January 2017 to September 2019 were retrospectively analyzed.All patients were treated with an open reduction and internal fixation method using locking titanium mini-plates and hollow screws or Kirschner wires.X-ray images were taken and follow-up was performed monthly after the operation;the internal fixation was then removed 4-5 mo after the operation;and the American Orthopedic Foot and Ankle Society(AOFAS)score was used for evaluation on the last follow-up.RESULTS All patients were followed up for 6-12 mo.A good/excellent AOFAS score was observed in 88.9%of patients.CONCLUSION For atypical Lisfranc joint complex injuries,active open reduction and internal fixation can be performed to enable patients to obtain a good prognosis and satisfactory functional recovery.展开更多
In millimeter wave(mmWave) multiple-input multiple-output(MIMO) systems, hybrid precoding has been widely used to overcome the severe propagation loss. In order to improve the spectrum efficiency with low complexity, ...In millimeter wave(mmWave) multiple-input multiple-output(MIMO) systems, hybrid precoding has been widely used to overcome the severe propagation loss. In order to improve the spectrum efficiency with low complexity, we propose a joint hybrid precoding algorithm for single-user mmWave MIMO systems in this paper. By using the concept of equivalent channel, the proposed algorithm skillfully utilizes the idea of alternating optimization to complete the design of RF precoder and combiner. Then, the baseband precoder and combiner are computed by calculating the singular value decomposition of the equivalent channel. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance with quite low complexity. Moreover, we investigate the effects of quantization on the analog components and find that the proposed scheme is effective even with coarse quantization.展开更多
Background: Acute dislocation of the thumb carpometacarpal (CMC) joint is a rare and challenging injury, and its treatment remains controversial. The purpose of the study was to evaluate the clinical outcome after sur...Background: Acute dislocation of the thumb carpometacarpal (CMC) joint is a rare and challenging injury, and its treatment remains controversial. The purpose of the study was to evaluate the clinical outcome after surgical repair of the dorsal capsulo-ligamentous complex. Materials and methods: Eight patients with a mean age of 39.8 years (range, 23 - 56 years) treated for the thumb CMC joint were treated in our hospital between 2008 and 2018. The ruptured dorsal capsulo-ligamentous complex was repaired using suture anchors in all patients, and the joint was immobilized with a Kirschner wire pinning and splint for 3 weeks. The clinical outcome was assessed by measuring the range of motion of the thumb CMC joint and the Japanese Society for Surgery of the Hand version of the Quick Disability of the Arm, Shoulder, and Hand (Q-DASH-JSSH) score. Results: The mean radial abduction of the thumb CMC joint was 66°, and the volar abduction was 63°. The mean Q-DASH-JSSH score was 4.8 (range, 0 - 15.6). There were no cases of infection, nerve disturbance, or osteoarthritis. Anatomical reduction was observed in seven patients at the final follow-up and in a rugby football player at 6 months of follow-up;however, subluxation of the thumb CMC joint at 12 months of follow-up due to reinjury was observed. Conclusion: Surgical repair of the dorsal capsulo-ligamentous complex with suture anchors is a reliable and simple treatment for acute unstable dislocation of the thumb CMC joint.展开更多
Taking cruciform welded joints under different corrosion degrees, together with 45° inclined angle and full penetration load-carrying fillet, as the research object, the stress intensity factor of a quarter-circu...Taking cruciform welded joints under different corrosion degrees, together with 45° inclined angle and full penetration load-carrying fillet, as the research object, the stress intensity factor of a quarter-circular comer crack of welded joints is calculated based on FRANC3D with ABAQUS. Effects of different corrosion pit sizes, crack aspect ratios, and crack depths on stress intensity factor are analyzed. The results show that pit depth plays a major role in stress intensity factor, while the effect of pit radius is relatively small. The cracking modes of the surface and the deepest point are mode I, and mixed modes I and II, respectively. Effects of pit depths, crack aspect ratios, and crack depths on the stress intensity factor at the surface point are greater than at the deepest point.展开更多
针对形状不规则复杂面目标多弹瞄准点优化算法计算效率低、稳定性差、优化能力不足的问题,提出一种基于弹药圆概率偏差(Circular Error Probable,CEP)的毁伤概率矩阵库(Damage Probability Matrix Library,DPML)和改进启发式退火优化机...针对形状不规则复杂面目标多弹瞄准点优化算法计算效率低、稳定性差、优化能力不足的问题,提出一种基于弹药圆概率偏差(Circular Error Probable,CEP)的毁伤概率矩阵库(Damage Probability Matrix Library,DPML)和改进启发式退火优化机制的高效瞄准点优化算法(Efficient Aiming Point Optimization Algorithm,EAPOA)。构建多弹瞄准点优化模型时,除考虑目标形状、导弹毁伤能力外,还考虑导弹直接毁伤、间接毁伤和多弹种联合毁伤等复杂因素对目标毁伤效果的影响。提出一种基于DPML的毁伤概率快速估计算法,提升算法优化效率和鲁棒性;设计一种基于候选瞄准点序列化的优化算法框架,并提出基于全局搜索和改进退火机制的启发式优化算法,降低瞄准点组合求解空间大小并提升算法优化能力。通过6个复杂面目标测试用例验证算法性能。研究结果表明,所提的EAPOA相比于增强精英保留策略遗传算法具有更强的优化能力,且平均优化时间仅为其1/5~1/3,在优化收益和计算效率上具有明显优势。展开更多
基金Science Foundation of Shenyang Medical College,No.20187076.
文摘BACKGROUND Lisfranc injuries have not received much attention by orthopedic doctors in the past,and there is little related research on the diagnosis and treatment of these injuries.In recent years with the rise in foot and ankle surgery,doctors are now paying more attention to this type of injury.However,there is still a high rate of missed diagnosis due to insufficient attention causing treatment delays or inadequate treatments,which eventually result in greater sequelae;including long-term pain,arthritis,foot deformity etc.In particular,for cases with a mild Lisfranc joint complex injury,the incidence of sequelae is higher.AIM To select an active surgical treatment for an atypical Lisfranc joint complex injury and to evaluate the clinical efficacy of the surgical treatment.METHODS The clinical data of 18 patients,including 10 males and 8 females aged 20-64 years with Lisfranc injuries treated in our department from January 2017 to September 2019 were retrospectively analyzed.All patients were treated with an open reduction and internal fixation method using locking titanium mini-plates and hollow screws or Kirschner wires.X-ray images were taken and follow-up was performed monthly after the operation;the internal fixation was then removed 4-5 mo after the operation;and the American Orthopedic Foot and Ankle Society(AOFAS)score was used for evaluation on the last follow-up.RESULTS All patients were followed up for 6-12 mo.A good/excellent AOFAS score was observed in 88.9%of patients.CONCLUSION For atypical Lisfranc joint complex injuries,active open reduction and internal fixation can be performed to enable patients to obtain a good prognosis and satisfactory functional recovery.
基金supported by NSFC (No. 61571055)fund of SKL of MMW (No. K201815) Important National Science & Technology Specific Projects (2017ZX03001028)
文摘In millimeter wave(mmWave) multiple-input multiple-output(MIMO) systems, hybrid precoding has been widely used to overcome the severe propagation loss. In order to improve the spectrum efficiency with low complexity, we propose a joint hybrid precoding algorithm for single-user mmWave MIMO systems in this paper. By using the concept of equivalent channel, the proposed algorithm skillfully utilizes the idea of alternating optimization to complete the design of RF precoder and combiner. Then, the baseband precoder and combiner are computed by calculating the singular value decomposition of the equivalent channel. Simulation results demonstrate that the proposed algorithm can achieve satisfactory performance with quite low complexity. Moreover, we investigate the effects of quantization on the analog components and find that the proposed scheme is effective even with coarse quantization.
文摘Background: Acute dislocation of the thumb carpometacarpal (CMC) joint is a rare and challenging injury, and its treatment remains controversial. The purpose of the study was to evaluate the clinical outcome after surgical repair of the dorsal capsulo-ligamentous complex. Materials and methods: Eight patients with a mean age of 39.8 years (range, 23 - 56 years) treated for the thumb CMC joint were treated in our hospital between 2008 and 2018. The ruptured dorsal capsulo-ligamentous complex was repaired using suture anchors in all patients, and the joint was immobilized with a Kirschner wire pinning and splint for 3 weeks. The clinical outcome was assessed by measuring the range of motion of the thumb CMC joint and the Japanese Society for Surgery of the Hand version of the Quick Disability of the Arm, Shoulder, and Hand (Q-DASH-JSSH) score. Results: The mean radial abduction of the thumb CMC joint was 66°, and the volar abduction was 63°. The mean Q-DASH-JSSH score was 4.8 (range, 0 - 15.6). There were no cases of infection, nerve disturbance, or osteoarthritis. Anatomical reduction was observed in seven patients at the final follow-up and in a rugby football player at 6 months of follow-up;however, subluxation of the thumb CMC joint at 12 months of follow-up due to reinjury was observed. Conclusion: Surgical repair of the dorsal capsulo-ligamentous complex with suture anchors is a reliable and simple treatment for acute unstable dislocation of the thumb CMC joint.
基金supported by the National Natural Science Foundation of China(51378430 and 51378431)
文摘Taking cruciform welded joints under different corrosion degrees, together with 45° inclined angle and full penetration load-carrying fillet, as the research object, the stress intensity factor of a quarter-circular comer crack of welded joints is calculated based on FRANC3D with ABAQUS. Effects of different corrosion pit sizes, crack aspect ratios, and crack depths on stress intensity factor are analyzed. The results show that pit depth plays a major role in stress intensity factor, while the effect of pit radius is relatively small. The cracking modes of the surface and the deepest point are mode I, and mixed modes I and II, respectively. Effects of pit depths, crack aspect ratios, and crack depths on the stress intensity factor at the surface point are greater than at the deepest point.
文摘针对形状不规则复杂面目标多弹瞄准点优化算法计算效率低、稳定性差、优化能力不足的问题,提出一种基于弹药圆概率偏差(Circular Error Probable,CEP)的毁伤概率矩阵库(Damage Probability Matrix Library,DPML)和改进启发式退火优化机制的高效瞄准点优化算法(Efficient Aiming Point Optimization Algorithm,EAPOA)。构建多弹瞄准点优化模型时,除考虑目标形状、导弹毁伤能力外,还考虑导弹直接毁伤、间接毁伤和多弹种联合毁伤等复杂因素对目标毁伤效果的影响。提出一种基于DPML的毁伤概率快速估计算法,提升算法优化效率和鲁棒性;设计一种基于候选瞄准点序列化的优化算法框架,并提出基于全局搜索和改进退火机制的启发式优化算法,降低瞄准点组合求解空间大小并提升算法优化能力。通过6个复杂面目标测试用例验证算法性能。研究结果表明,所提的EAPOA相比于增强精英保留策略遗传算法具有更强的优化能力,且平均优化时间仅为其1/5~1/3,在优化收益和计算效率上具有明显优势。
