Lateral stiffness of corner-supported steel modular frame with splice connection

Yi-Fan Lyu,Guo-Qiang Li,Ke Cao,Si-Yuan Zhai,De-Yang Kong,Xuan-Yi Xue,Heng Li 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.48 No.3

This paper proposes a comprehensive investigation on lateral stiffness of corner-supported steel modular frame using splice connection. A full-scale modular frame with two stacked steel modules under lateral load is tested. Ductile pattern in the transfer of lateral load is found in the final failure mode. Two types of lateral stiffness, including tangent stiffness and secant stiffness, are defined from the load-displacement due to the observed nonlinearity. The difference between these two types of stiffness is found around 20%. The comparisons between the experimental lateral stiffness and the predictions of classical methods are also conducted. The D-value method using hypothesis of independent case is a conservative option for predicting lateral stiffness, which is more recommended than method of contraflexural bending moment. Analyses on two classical shortrod models, including fix-rod model and pin-rod model, are further conducted. Results indicate that fix-rod model is more recommended than pin-rod model to simplify splice connection for simulation on lateral stiffness of modular frame in elastic design stage.

Modified Procedures for ALPPS Based on a Risk-Reduced Strategy: Paralleled Clinical Evaluation at Multiple Institutions

Ya-Lin Kong,Ying Xing,Jie Li,Cheng-Li Liu,Xiao-Jun He,Cheng Wang,Jiang-Min Chen,Ling-Hong Kong,Xu Han,Hong-Yi Zhang 연세대학교의과대학 2021 Yonsei medical journal Vol.62 No.10

Purpose: We compared the clinical outcomes of modified procedures for associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) based on a risk-reduced strategy with those of classic ALPPS procedures in treating large liver carcinoma. Materials and Methods: Short-term outcomes, increases in future liver remnant (FLR) and functional FLR (FFLR), and overall survival (OS) were compared between 45 consecutive patients treated with modified ALPPS procedures and 34 patients treated with classic ALPPS procedures. Results: Clinical outcomes after the 1st-stage operation markedly improved with the modified procedures. Although the proportions of liver cirrhosis and hepatocellular carcinoma were higher in the modified group, the mortality and incidence of severe complications did not increase. FLR and FFLR hypertrophy at 1 week after the 1st-stage operation were similar in both groups; however, kinetic growth rates in the modified group were lower. OS rates were similar. Conclusion: Modified ALPPS procedures could be safely applied to provide long-term survival for patients with liver cirrhosis without sufficient FLR.

일차 슬관절 전치환술 시 내·외반 구속형 치환물이 필요했던 사례들의 원인 분석

공동의(Dong Yi Kong),박상훈(Sang Hoon Park),최충혁(Choong Hyeok Choi) 대한정형외과학회 2021 대한정형외과학회지 Vol.56 No.3

목적: 일차 슬관절 전치환술 시에는 일반적으로 가능한 한 구속력이 적은 치환물을 이용한 슬관절 전치환술이 권장된다. 그럼에도 불구하고 후방 십자인대 보존형 혹은 대치형 치환물로 적절한 슬관절 안정성을 얻기가 불가능한 경우에는 수술 중 내ㆍ외반 구속형 슬관절 치환물로 전환을 고려해야 한다. 내ㆍ외반 구속형 치환물이 항시 구비되어 있지 않는 국내 현실을 감안하여 일차 슬관절 전치환술의 효율적인 술 전 계획을 위해 내ㆍ외반 구속형 슬관절 치환물을 준비하는 적응증을 제시하고자 본 연구를 시행하였다. 대상 및 방법: 2003년 5월부터 2016년 2월까지 시행되었던 일차 슬관절 전치환술 1,797예 중 내ㆍ외반 구속형 슬관절 치환물로 일차 슬관절 전치환술이 시행되었던 27명(29예)를 대상으로 내ㆍ외반 구속형 슬관절 치환물로 최종 결정한 원인 등을 후향적으로 분석하였다. 결과: 일차 슬관절 전치환술 시 내ㆍ외반 구속형 슬관절 치환물이 사용된 경우는 전체 일차 슬관절 전치환술 중 29예로 1.6%의 빈도를 보였다. 남자 6명, 여자 21명이었으며, 2명에서 양측 모두 내ㆍ외반 구속형 치환물이 필요하였다. 환자의 나이는 평균 63.4세(34–79세)였고, 술 전 최대신전각도는 평균 16.2° (-20°–90°), 최대굴곡각도는 평균 111.7° (35°–145°)였다. 일차 슬관절 전치환술 시 내ㆍ외반 구속형 치환물이 필요하였던 원인으로는 심한 외반 변형으로 내ㆍ외반 불안정성을 보강하기 위한 경우가 10예, 심한 강직으로 인해 내ㆍ외반 구속형 치환물이 사용되었던 경우가 10예였으며, 과거력상 내측측부인대 4예, 외측측부인대 1예, 원위 대퇴골과의 무혈성 괴사로 인한 경우가 4예였다. 심한 외반 변형으로 수술을 시행한 10예 경우의 술 전 슬관절 전후방기립 사진상 해부학적 대퇴경골간각은 평균 25.7° (21°–43°)의 외반각을 보였고, 심한 강직으로 수술을 시행한 10예 경우의 굴곡 구축은 평균 37.5° (20°–90°), 관절운동범위는 평균 48.5° (10°–70°)였다. 결론: 20° 이상의 해부학적 대퇴경골간각의 외반 변형, 굴곡 구축 20° 이상 및 관절운동범위 70° 이하를 가진 관절운동 제한, 과거 측부인대 손상 병력이 의심되는 경우에는 일차슬관절 전치환술 시라도 술 전 계획 시 내ㆍ외반 구속형 치환물을 준비하는 것이 수술 중 발생할 수 있는 불안정성의 해결에 도움이 될 것으로 생각된다. Purpose: The least constrained prosthesis is generally recommended in primary total knee arthroplasty (TKA). Nevertheless, a varus/valgus constrained (VVC) prosthesis should be implanted when a semi-constrained prosthesis is not good for adequate stability, especially in the coronal plane. In domestic situations, however, the VVC prosthesis could not always be prepared for every primary TKA case. Therefore, it is sometimes impractical to use a VVC prosthesis for unsual unstable situations. This study provides information for preparing VVC prostheses in the preoperative planning of primary TKA through an analysis of primary VVC TKA cases. Materials and Methods: This study reviewed 1,797 primary TKAs, performed between May 2003 and February 2016. The reasons for requiring VVC prosthesis and the preoperative conditions in 29 TKAs that underwent primary TKA with a VVC prosthesis were analyzed retrospectively. Results: In primary TKA, 29 cases (1.6%) in 27 patients (6 male and 21 female) used VVC prosthesis. Two patients underwent a VVC prosthesis on both knees. The mean age of the patients was 63.4 years old (34–79 years). The mean flexion contracture was 16.2° (-20°–90°), and the mean angle of great flexion was 111.7° (35°–145°). The situations requiring a VVC prosthesis were severe valgus deformity in 10 knees, knee stiffness requiring extensive soft tissue release in 10 knees, previously injured collateral ligaments in five knees, and distal femoral bone defect due to avascular necrosis in four knees. The mean tibiofemoral angle was 25.7° (21°–43°) in 10 cases with a valgus deformity. The mean flexion contracture was 37.5° (20°–90°), and the mean range of motion was 48.5° (10°–70°) in 10 cases with knee stiffness. Conclusion: The preparation of VVC prosthesis is recommended, even for primary TKA in cases of severe valgus deformity (tibiofemoral angle>20°), stiff knee (the range of motion: less than 70° with more than 20° flexion contracture), and the cases with a previous collateral ligament injury. This information will help in the preparation of adequate TKA prostheses for unusual unstable situations.

Loss-of-function HSD17B13 variants, non-alcoholic steatohepatitis and adverse liver outcomes: Results from a multi-ethnic Asian cohort

( Yi-wen Ting ),( Amanda Shen-yee Kong ),( Shamsul Mohd Zain ),( Wah-kheong Chan ),( Hwa-li Tan ),( Zahurin Mohamed ),( Yuh-fen Pung ),( Rosmawati Mohamed ) 대한간학회 2021 Clinical and Molecular Hepatology(대한간학회지) Vol.27 No.3

Background/ Aims: 17β-hydroxysteroid dehydrogenase 13 (HSD17B13) variants were recently reported to have significantly lower odds of non-alcoholic fatty liver disease (NAFLD). This is a two-part study that aimed to evaluate the association of HSD17B13 variants with NAFLD and its histological severity, and to identify the association of the variants with clinical outcomes in a cohort of biopsy-proven NAFLD patients. Methods: Consecutive biopsy-proven NAFLD patients and controls without fatty liver were recruited for this study between 2009 and 2014. Genotyping for HSD17B13 variants was performed using rhAmp assays. A total of 165 patients with NAFLD were monitored up until August 2019. Clinical outcomes were recorded. Results: HSD17B13 rs72613567 TA allele and rs6834314 G allele were associated with lower odds of non-alcoholic steatohepatitis (NASH) in the overall cohort and among ethnic Chinese, but not among ethnic Malays or Indians (P<0.05). During a mean follow-up of 89 months, 32 patients (19.4%) experienced at least one clinical outcome (cardiovascular events, n=22; liver-related complications, n=6; extra-hepatic malignancy, n=5; and mortality, n=6). The rs72613567 homozygous TA allele and the rs6834314 homozygous G allele were independently associated with a lower incidence of liver-related complications (hazard ratio [HR], 0.004; 95% confidence interval [CI], 0.00-0.64; P=0.033 and HR, 0.01; 95% CI, 0.00-0.97; P=0.048, respectively) and were associated with lower grade of hepatocyte ballooning among the ethnic Chinese. Conclusion: HSD17B13 rs72613567 and rs6834314 variants were inversely associated with NAFLD and NASH, and were associated with lower incidence of adverse liver outcomes in a cohort of multi-ethnic Asian patients with NAFLD. (Clin Mol Hepatol 2021;27:486-498)

Long-term health monitoring for deteriorated bridge structures based on Copula theory

Yi Zhang,Chul-Woo Kim,Kong Fah Tee,Akhil Garg,Ankit Garg 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.21 No.2

Maintenance of deteriorated bridge structures has always been one of the challenging issues in developing countries as it is directly related to daily life of people including trade and economy. An effective maintenance strategy is highly dependent on timely inspections on the bridge health condition. This study is intended to investigate an approach for detecting bridge damage for the long-term health monitoring by use of copula theory. Long-term measured data for the seven-span plate-Gerber bridge is investigated. Autoregressive time series models constructed for the observed accelerations taken from the bridge are utilized for the computation of damage indicator for the bridge. The copula model is used to analyze the statistical changes associated with the modal parameters. The changes in the modal parameters with the time are identified by the copula statistical properties. Applicability of the proposed method is also discussed based on a comparison study among other approaches.

Synthesis and characterization of ZnO/MgZnO heterostructure nanorods by simple two-step evaporation

Kong, Bo Hyun,Mohanta, Sanjay Kumar,Kim, Young Yi,Cho, Hyung Koun IOP Pub 2008 Nanotechnology Vol.19 No.8

<P>ZnO-core/MgZnO-shell heterostructure nanorods with high aspect ratio were synthesized using a two-step thermal evaporation procedure, in which the core and the shell layers were formed separately at different temperatures. Microstructural characterization revealed a position dependence of the crystal structure and composition in the shell layer. The shell layer in the upper region consisted of MgO with quantum dot-like structure having cubic phases embedded in an amorphous oxide layer, while a Mg<SUB>0.35</SUB>Zn<SUB>0.65</SUB>O shell layer with a self-assembled superlattice structure of triple periodicity was formed in the middle region. </P>

Hierarchical reinforcement learning from competitive self-play for dual-aircraft formation air combat

Kong Wei-ren,Zhou De-yun,Zhou Ying,Zhao Yi-yang 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.2

The recent development of technology helps in the revolutionary war and it controls the war which is influenced by brilliant planning. The maneuver aircraft of intelligent algorithm aids the pilot to decide the particular position on the battlefield. Nowadays the hardware components of radar and missiles are widely used and the beyond visual range is the most popular method applied in air combat. The introduction of close-range air combat maneuver decisions generates the attention of researchers in artificial intelligence. Most of the existing methods are based on autonomous aircraft focused in air combat scenario but manual air combats are widely applied in dual aircraft. Based on the factors mentioned above, a novel hierarchical maneuver decision architecture is applied to a dual-aircraft close-range air combat scenario. Subsequently, the soft actor-critic algorithm is merged with competitive self-play which integrates the knowledge of sub-strategies. Further, the reinforcement learning technique is employed to achieve an approximate Nash equilibrium master strategy. The experimental results show that the hierarchical architecture exhibits good performance, symmetry, and robustness. The research generates a solution for intelligent formation of air combat in the future and guidance for manned or unmanned aircraft cooperative combat.

Systematic Framework to Assess Genome-wide Metabolic Environment of Lactic Acid Bacteria Reveals Diet and Strain-specific Probiotic Traits

Yi Qing LEE,Lokanand KODURU,Meiyappan LAKSHMANAN,Pooi-Leng HO,Pei-Yu LIM,Wei Xuan LER,Say Kong NG,Dongseok KIM,Doo-Sang PARK,Mazlina BANU,Dave Siak-Wei OW,Dong-Yup LEE 한국생물공학회 2022 한국생물공학회 학술대회 Vol.2022 No.9

Modeling and coordinative optimization of NOx emission and efficiency of utility boilers with neural network

Yi Zhang,Yanjun Ding,Zhansong Wu,Liang Kong,Tao Chou 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.6

empirical model to predict the boiler efficiency and pollutant emissions was developed with artificialneural networks based on the experimental data on a 360 MW W-flame coal fired boiler. The temperature of the furnacewas selected as an intermediate variable in the hybrid model so that the predictive precision of NOx emissions was en-hanced. The predictive precision of the hybrid model was operational objects were proposed in order to minimize the fuel and environmental costs. Based on the neural networkmodel and optimal objects, a genetic algorithm was employed to seek real-time solution every 30 seconds. Optimummanipulated variables such as excess air, primary air and secondary air were obtained under different optimal objects.The above algorithm interconnected with a distributed control system (DCS) formed the supervisory control and achievedreal-time coordinated optimization control of utility boilers.

Influence of underlying layers on the growth of 1D (Mg,Zn)O nanorods

Kong, Bo Hyun,Jun, Sang Ouk,Kim, Young Yi,Kim, Dong Chan,Cho, Hyung Koun WILEY-VCH Verlag 2007 Physica Status Solidi. B Vol.244 No.5

<P>We grew (Mg,Zn)O nanorods with different morphologies and growth directions on various substrates by the thermal evaporation process using vapor-solid growth mode. The alignment and growth mode of the nanorods are significantly affected by the underlayer and substrates. By depositing ZnO and (Mg,Zn)O underlayers, the alignment of the (Mg,Zn)O nanorods was changed from random to vertical based on the substrate surface. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)</P>