A Review of On-Orbit Servicing Robot Teleoperation Control System

Xiao Zhong,Yan ShiQiang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.11

On-orbit servicing robots were developed to complete the missions in the uncertain and hazards outer space. The operator controls the remote robot via teleoperation systems, which allows the operator to manipulate the robot at a distance. But, as the existing of communication time-delay affects the whole system stability, transparency and other performance index. Consequently, a proper teleoperation system could help the operator to perform missions more accurate. This paper presents the general scheme of the teleoperation system, compares the four typical control modes and estimates methods of time-delay. At last provides an outlook to future research directions.

Bone Grafting Can Promote the Prognosis of Displaced Femoral Neck Fractures: A Follow-up of the Clinical Significance of Bone Defects

Xiaozhong Zhu,Wei Wang,Zhiyuan Wang,Yi Zhu,Guangyi Li,Jiong Mei 대한정형외과학회 2023 Clinics in Orthopedic Surgery Vol.15 No.4

Background: Femoral neck fractures (FNFs) comprise a large proportion of osteoporotic fractures in Asia. However, the full range of prognostic variables that affect prognosis remains unclear. Here, we aimed to determine whether the severity of bone defects at the fracture site and other variables impact the prognosis of displaced FNFs. Methods: We evaluated the incidence of FNF internal fixation failures at regular intervals after surgery in data collected retrospectively. Digital Imaging and Communications in Medicine (DICOM) magnetic resonance imaging data of the displaced FNFs of 204 patients (> 20 years old; mean age, 52.3 years; men, 55.4%) who underwent internal fixation were used to construct threedimensional (3D) virtual models of the femoral neck region. We calculated the position and volume of bone defect (VBD) using our independently developed algorithm and Mimics software. Each participant was followed up for at least 24 months; complications were noted and correlated with VBD and demographic and clinical variables. Results: On the basis of VBD values calculated from virtual reduction models, 57 patients were categorized as having a mild defect, 100 as having a moderate defect, and 47 as having a severe defect. Age (p = 0.046) and VBD (p < 0.001) were significantly correlated with internal fixation failure. Multivariate analysis revealed that severe bone defects were associated with internal fixation failure (adjusted odds ratio [aOR], 23.073; 95% confidence interval [CI], 2.791–190.732) and complications (aOR, 8.945; 95% CI, 1.829–43.749). In patients with a severe defect, bone grafting was inversely associated with internal fixation failure (aOR, 0.022; 95% CI, 0.002–0.268) and complications (aOR, 0.023; 95% CI, 0.002–0.299). Conclusions: Bone defect severity was associated with internal fixation failure and other complications. For young adults with large VBDs, bone grafting of the defect can reduce the risk of internal fixation failure. These results provide useful new quantitative information for precisely classifying displaced FNFs and guiding subsequent optimal treatments.

A NUMERICAL SIMULATION OF STRIP PROFILE IN A 6-HIGH COLD ROLLING MILL

XIAOZHONG DU,QUAN YANG,CHENG LU,ANH KIET TIEU,SHINIL KIM 한국소성가공학회 2008 한국소성가공학회 컨퍼런스 Vol.2008 No.10

Kynurenine 3-monooxygenase is a critical regulator of renal ischemia–reperfusion injury

Xiaozhong Zheng,Ailiang Zhang,Margaret Binnie,Kris McGuire,Scott P. Webster,Jeremy Hughes,Sarah E. M. Howie,Damian J. Mole 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Acute kidney injury (AKI) following ischemia–reperfusion injury (IRI) has a high mortality and lacks specific therapies. Here, we report that mice lacking kynurenine 3-monooxygenase (KMO) activity (Kmonull mice) are protected against AKI after renal IRI. We show that KMO is highly expressed in the kidney and exerts major metabolic control over the biologically active kynurenine metabolites 3-hydroxykynurenine, kynurenic acid, and downstream metabolites. In experimental AKI induced by kidney IRI, Kmonull mice had preserved renal function, reduced renal tubular cell injury, and fewer infiltrating neutrophils compared with wild-type (Kmowt) control mice. Together, these data confirm that flux through KMO contributes to AKI after IRI, and supports the rationale for KMO inhibition as a therapeutic strategy to protect against AKI during critical illness.

A new dynamic risk evaluation model infuzzy AHP based engineering project life-cycle

Yu Xiaozhong,Chen Jiansheng 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Each project contains some degree of risk and it is required to be aware of these risks and to develop the necessary reasonable risk evaluation model to get the exact risk value of the project. Becausej projects" risks are multidimensional, changing during the project life-cycle, and can not be describled in crisp numbers, they must be evaluated by using multi-criteria decision-making method which can consider the time changing and interval numbers. The aim of this article is to provide an evaluation tool to evaluate the project risks under incomplete and vague information more exact than the present models. The article proposes a improved dynamic fuzzy analytic hierarchy process (AHP) model basing on project life-cycle, and the new model is a suitable and practical way of evaluating project risks.

通過紙張的治理 : 1960年代的上海改造

孫曉忠(Sun Xiaozhong) 중국문화연구학회 2011 중국문화연구 Vol.0 No.19

본 논문은 종이 물질사(物質史) 연구를 통해 1960년대 신민주주의 문화 실천 속에서 있었던 지역, 특히 상하이(上海)에 대한 개조와 문화에 대한 독특한 관리통제방식을 토론하면서, 신민주주의가 자본주의를 처리하는 특수한 경험을 고찰하고자 하였다. 60년대 상하이 문화는 신구(新舊) 사이의 과도기성과 경계성을 가지고 그 풍부성을 드러내고 있었지만, 신민주주의 문화의 적극성과 개성은 등한시되었으며, 사회주의 중국 건설에서의 '문화'의 중요성을 약화시켰다. 이 시기 상하이 문화는 불안전성과 유동성을 가지고 해방 전과 달랐으며, 사회주의 개조가 끝나고 난 후의 안정적 문화구조와도 다른 양상을 띠었다. 1960년대 신문출판부서는 상하이에서의 종이생산에 대한 계획적 관리통제를 진행하였다. 종이의 통제로 해방 전 혼란스런 민간인쇄출판 시장을 정돈하였고, 국영출판인쇄소를 강화하였다. 1963년 제1차 6개년 계획이 실행되었고, 출판총서(出版總暑)는 <신문종이 통일적인 분배조달 방법新聞紙統一分配調撥辦法>, <신문출판단위 용지 기준 규정新聞出版單位用紙標準的規定> 문건을 하달하여, 문화 용지 사용에 대한 구체적인 심사와 감독하였다. 논문은 1964년 "신문지사건", 즉 용지 생산과 분배에서의 관리 문제로, "민간 출판 투기상의 통제에 방어선이 무너진" 사건을 상세히 서술하였고, 건국초기 종이생산과 분배를 통한 출판인쇄사업의 관리 통제방식과 당시 상하이 신문잡지 출판계 문화현상을 논술하였다.

Reliability Analysis of Unrepairable Systems with Uncertain Lifetimes

Ying Liu,Xiaozhong Li,Congcong Xiong 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.12

The topic of unrepairable system is an important content in system reliability theory. There are many reasons cannot be repaired, some because of technical reasons, cannot repair, some because of economic reasons, not worth to repair, and some because of making repairable system simplification. So it is essential to pay attention to unrepairable systems. In this paper, the lifetimes of unrepairable systems are considered as uncertain variables. Based on that, the fundamental mathematical models of series systems, parallel systems, series-parallel systems and parallel-series systems are established, respectively. Furthermore, we make reliability analysis of above four unrepairable systems, respectively. Some numerical examples are also given for illustration.

A Bidirectional Single-Stage DC/AC Converter for Grid Connected Energy Storage Systems

Jianliang Chen,Xiaozhong Liao,Deshang Sha 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

In this paper, a unified control strategy using the current space vector modulation (CSVM) technique is proposed and applied to a bidirectional three-phase DC/AC converter. The operation of the converter changes with the direction of the power flow. In the charging mode, it works as a buck type rectifier; and during the discharging mode, it operates as a boost type inverter, which makes it suitable as an interface between high voltage AC grids and low voltage energy storage devices. This topology has the following advantages: high conversion efficiency, high power factor at the grid side, tight control of the charging current and fast transition between the charging and discharging modes. The operating principle of the mode analysis, the gate signal generation, the general control strategy and the transition from a constant current (CC) to a constant voltage (CV) in the charging mode are discussed. The proposed control strategy has been validated by simulations and experimental results obtained with a 1kW laboratory prototype using supercapacitors as an energy storage device.

Detrital-zircon geochronology and Hf isotope of Paleozoic sedimentary rocks in the Jilin Province, NE China: tectonic significance for microcontinental blocks of eastern Central Asian Orogenic Belt

Chenglong Shi,Xiaozhong Ding,Yanxue Liu,Xiaodong Zhou 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.5

We undertook U-Pb-Hf isotope testing of detrital zircons from Late Paleozoic sedimentary rocks in the Jilin Province, NE China, with the aim of constraining the tectonic evolution of eastern Central Asian Orogenic Belt. The age populations of the detrital zircons from the sandstone of the Jiefangcun Formation in the Songliao Block are ~2234, ~1782, ~1030–921, ~817, ~540, and ~381–254 Ma, whereas those of the zircons from the greywacke of the Permian Kedao Formation in the Songliao Block yield are ~2436, ~1905, ~1692, 1146–1170, ~554–498, and ~342–255 Ma. Combined Hf isotope characteristics, these ages reveal that: (1) rocks from the Jiefangcun and Kedao formations were deposited after 254 and 255 Ma, respectively; (2) these formations were sourced mainly from the Songliao Block and the Jiamus Terrane in the eastern CAOB and to a lesser amount, from the northern margin of the NCC; and (3) it appears that several remnants of ancient Precambrian basement occur adjacent to these Late Paleozoic strata that occur within the microcontinental blocks. Detrital zircons from the silty sandstone of the Miaoling Formation in the western margin of the Khanka Terrane yield peak age populations of 508–476, 463–396, and 348–258 Ma, having similar εHf(t) values to those obtained from zircons within the Jiamusi Terrane. These data indicate that (1) deposition of the Miaoling Formation in the western margin of the Khanka Terrane had started by 258 Ma, and (2) these sediments were sourced mainly from the Jiamusi Terrane and local magmatic rocks. The widespread occurrence of detrital zircons with ages of 480–550 Ma and positive εHf(t) values within the Late Paleozoic strata in the Songliao Block and the Jiamusi–Khanka Terrane, indicates that the amalgamation of these blocks took place during the middle stage of the Paleozoic, probably after the Silurian, prior to the Late Permian.

Investigation on the microstructure and fracture behavior of super-eutectic ZA alloy welded joint by pulse fiber laser

Fei Yan,Xiaozhong Du,Fang Chai,Chunming Wang,Kejia Zhuang,Juan Zhao,Wei Wang 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.6

In this study, we present the experimental laser welding of super-eutectic ZA alloy. Microstructures of the ZA alloy′s bond area welded by pulsed laser were investigated using an optical microscope, scanning electron microscope, energy diffraction spectrum and X-Ray diffractometer. The results showed that microstructures in the weld mainly consisted of threadlike columnar crystals, coarse dendrites and fine equiaxed grains. Secondary particles were produced in the interdendritic zones because of the composition segregation. A poor Al area was formed inside the η grain while a rich Al area takes shape outside the η grain. The occurrence of the composition segregation can increase the grain boundary cracking tendency. The existence of a large number of η phase greatly intensified the brittle of this material. The presence of many cleavage steps in the fractograph principally depended on the secondary cleavage effect between two cleavage cracks on different planes. The evolution of cracks along the twinning plane was the result of the secondary cleavage substituting for the twinning deformation in the vicinity of the crack tip.