• Title/Summary/Keyword: poor connection

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Evaluation of Bending Creep Performance of Laminated Veneer Lumber (LVL) Formwork for the Design of Timber Concrete Composite (TCC) Structures

  • Hyun Bae KIM;Takuyuki YOSHIOKA;Kazuhiko FUJITA;Jun ITO;Haruka NOHARA;Keiji NOHARA;Toshiki NARITA;Wonwoo LEE;Arata HOSOKAWA;Tetsuiji TANAKA
    • Journal of the Korean Wood Science and Technology
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    • v.52 no.4
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    • pp.375-382
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    • 2024
  • The study focuses on evaluating the bending creep performance of laminated veneer lumber (LVL) formwork in timber concrete composite (TCC) structures. Timber-framed construction is highlighted for its environmental benefits and seismic resistance, but limitations such as poor tensile strength and brittle failure in bending hinder its use in high-rise buildings. Wood-concrete hybrid structures, particularly those using reinforced concrete slabs with TCC floors, emerge as a potential solution. The research aims to understand the time-dependent behavior of TCC components, considering factors like wood and concrete shrinkage and connection creep. The experiment was conducted in western Japan on the TCC floor designed for use in the Kama-city Inatsuki-higashi compulsory education school. The LVL formwork, measuring 9,000 mm by 900 mm, and concrete is loaded onto it for testing. The creep test periods are examined using concrete loading. It employs a comprehensive creep analysis, adhering to Japanese standards, involving deflection measurements and regression analysis to estimate the creep coefficient. Results indicate substantial deformation after shoring removal, suggesting potential reinforcement needs. The study recommends extending test periods for improved accuracy and recognizing regional climate impacts. Overall, the research provides valuable insights into the potential of LVL formwork in TCC structures, emphasizing safety considerations and paving the way for further experimentation under varied conditions to validate structural integrity.

Surgical Results and Risk Facor Analysis of the Patients with Single Ventricle Associated with Total Anomalous Pulmonary Venous Connection (총폐정맥연결이상증을 동반한 단심증 환아의 수술결과 및 위험인자 분석)

  • 이정렬;김창영;김홍관;이정상;김용진;노준량
    • Journal of Chest Surgery
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    • v.35 no.12
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    • pp.862-870
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    • 2002
  • The surgical results of the patients with single ventricle(SV) associated with total anomalous pulmonary venous connection(TAPVC) has been reported with high mortality and morbidity due to their morphologic and hemodynamic complexity. A retrospective review was undertaken to report the outcome of the first-stage palliative surgery in our institution and to determine the factors influencing early death. Material and Method: Between January 1987 and June 2002, 39 patients with SV and TAPVC underwent surgical intervention with or without TAPVC repair. Age at operation ranged from 1day to 10.7months (median age, 2.4month), and 29 patients were male. Preoperative diagnosis included 20 right-dominant SV, 15 SV with endocardial cushion defect, 3 left-dominant SV, and 1 tricuspid atresia. The pulmonary venous connection was supracardiac in 22, cardiac in 5, infracardiac in 11, and mixed in 1, Obstructed TAPVC was present in 11. First-stage palliative surgery was performed in 37. Repair of TAPVC, either alone or in association with other procedures, was performed during the initial operation in 31. Univariate and multivariate analyses were performed to analyze the risk factors influencing the operative death. Result: A mean follow-up period of survivors was 34.3 $\pm$ 43.0(0.53 ~ 146.2)months. Overall early operative mortality was 43.6%(17/39). The causes were low cardiac output in 8, failure of weaning from cardiopulmonary bypass in 3, sepsis in 2, pulmonary hypertensive crisis in 1, pulmonary edema in 1, pneumonia in 1, and postoperative arrhythmia in 1. Risk factors influencing early death in univariate analysis were body weight, surgical intervention in neonate, obstructive TAPVC, preoperative conditions including metabolic acidosis, and need for inotropic support, TAPVC repair in initial operation, operative time, and cardiopulmonary bypass(CPB) time. In multivariable analysis, body weight, age at initial operation, surgical intervention in neonate, preoperative conditions including metabolic acidosis, need for inotropic support and CPB time were the risk factors. Conclusion: In this study, we demonstrated that the patients with SV and TAPVC had high perioperative mortality. Preoperative poor condition, young age, the length of operative and CPB time, the presence of obstructive TAPVC had been proven to be the risk factors. This fact suggests that the avoidance of unnecessarily additional procedures may improve the surgical outcomes of the first-stage palliative surgery. However further observation and collection of the data is mandatory to determine the ideal surgical strategy.

A Study on Building of City Image through the Design System for Public Transportation - Focus on the Design Case for Seoul Public Transportation - (대중교통 디자인시스템을 통한 도시이미지 형성에 관한 연구 - 서울시 대중교통 디자인의 아이덴티피케이션 개념적용과 시스템화 방안 -)

  • Yang, Seung-Ju;Kim, Byung-Jin
    • Archives of design research
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    • v.19 no.1 s.63
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    • pp.89-98
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    • 2006
  • As the concept of city changes city is viewed in the perspective of business to make profits, not in the perspective of physical space. In the case of Korea urbanization processed over the level of 80% and the formation of identity is suggested for the way to improve city competitiveness as of globalization and liberalization. Seoulentered the level of developed countries in the perspective of functions and facilities, but its image is evaluated poor because of the lack of cultural competitiveness, tourismattractiveness and service system. Dependency of public transportation which is public facilities representing city indirectly is very high, but in information service and visual systems of pubic transportation operations and management are not enough and differentiated image and loyalty are hard to find. In 2004 government of city of Seoul suggested modifications, but compared to London, Paris and Tokyo consistent system, the lack of control and management of use environment of design, excessive visual information and destruction of connection are pointed out. Therefore to solve these problems the introduction of design system is needed to develop identity after applying characteristics and regulations for using to disordered visual stuff. These procedurescan be explained as City Identity Program (CIP) and this study tries to embody city image through public transportation design system. As the study method for this the status of public transportation design system of London, Paris and Tokyo were searched and compared to that of Seoul. Based on this systematization of symbol marks per public transportation being used right now, the development of design guidelines to form identity, relation of design and the strategy of systematization per method and media were proposed.

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Design and Implementation of a Hardware-based Transmission/Reception Accelerator for a Hybrid TCP/IP Offload Engine (하이브리드 TCP/IP Offload Engine을 위한 하드웨어 기반 송수신 가속기의 설계 및 구현)

  • Jang, Han-Kook;Chung, Sang-Hwa;Yoo, Dae-Hyun
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.9
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    • pp.459-466
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    • 2007
  • TCP/IP processing imposes a heavy load on the host CPU when it is processed by the host CPU on a very high-speed network. Recently the TCP/IP Offload Engine (TOE), which processes TCP/IP on a network adapter instead of the host CPU, has become an attractive solution to reduce the load in the host CPU. There have been two approaches to implement TOE. One is the software TOE in which TCP/IP is processed by an embedded processor and the other is the hardware TOE in which TCP/IP is processed by a dedicated ASIC. The software TOE has poor performance and the hardware TOE is neither flexible nor expandable enough to add new features. In this paper we designed and implemented a hybrid TOE architecture, in which TCP/IP is processed by cooperation of hardware and software, based on an FPGA that has two embedded processor cores. The hybrid TOE can have high performance by processing time-critical operations such as making and processing data packets in hardware. The software based on the embedded Linux performs operations that are not time-critical such as connection establishment, flow control and congestions, thus the hybrid TOE can have enough flexibility and expandability. To improve the performance of the hybrid TOE, we developed a hardware-based transmission/reception accelerator that processes important operations such as creating data packets. In the experiments the hybrid TOE shows the minimum latency of about $19{\mu}s$. The CPU utilization of the hybrid TOE is below 6 % and the maximum bandwidth of the hybrid TOE is about 675 Mbps.

Comparison of PI and PR Controller Based Current Control Schemes for Single-Phase Grid-Connected PV Inverter (단상 계통 연계형 태양광 인버터에 사용되는 PI 와 PR 전류제어기의 비교 분석)

  • Vu, Trung-Kien;Seong, Se-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.8
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    • pp.2968-2974
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    • 2010
  • Nowadays, the PV systems have been focused on the grid connection between the power source and the grid. The PV inverter can be considered as the core of the whole system because of an important role in the grid-interfacing operation. An important issue in the inverter control is the load current regulation. In the literature, Proportional Integral (PI) controller, which is normally used in the current-controlled Voltage Source Inverter (VSI), cannot be a satisfactory controller for an AC system because of the steady-sate error and the poor disturbance rejection, especially in high-frequency range. Compared with conventional PI controller, Proportional Resonant (PR) controller can introduce an infinite gain at the fundamental frequency of the AC source; hence it can achieve the zero steady-state error without requiring the complex transformation and the de-coupling technique. Theoretical analyses of both PI and PR controller are presented and verified by simulation and experiment. Both controller are implemented in a 32-bit fixed-point TMS320F2812 DSP processor and evaluated on a 3kW experimental prototype PV Power Conditioning System (PCS). Simulation and experimental results are shown to verify the controller performances.

Secure Jini Service Architecture Providing Ubiquitous Services Having Persistent States (유비쿼터스 서비스 상태지속을 지원하는 안전한 Jini 서비스 구조)

  • Kim, Sung-Ki;Jung, Jin-Chul;Park, Kyung-No;Min, Byoung-Joon
    • The KIPS Transactions:PartC
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    • v.15C no.3
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    • pp.157-166
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    • 2008
  • The ubiquitous service environment is poor in reliability of connection and also has a high probability that the intrusion against a system and the failure of the services may happen. Therefore, It is very important to guarantee that the legitimate users make use of trustable services from the viewpoint of security without discontinuance or obstacle of the services. In this paper, we point out the problems in the standard Jini service environment and analyze the Jgroup/ARM framework that has been developed in order to help fault tolerance of Jini services. In addition, we propose a secure Jini service architecture to satisfy the security, availability and quality of services on the basis of the analysis. The secure Jini service architecture we propose in this paper is able to protect a Jini system not only from faults such as network partition or server crash, but also from attacks exploiting flaws. It provides security mechanism for dynamic trust establishment among the service entities. Moreover, our secure Jini service architecture does not incur high computation costs to merge the user service states because of allocation of the replica based on each session of a user. Through the experiment on a test-bed, we have confirmed that proposed secure Jini service architecture is able to guarantee the persistence of the user service states at the level that the degradation of services quality is ignorable.

Assessment of Damages for Non-pecuniary Loss and Compensation for Damages in Medical Accidents - Overview for Cases of Medical Injury Relief in Korea Comsumer Agency - (의료사고의 손해배상과 위자료 산정 -한국소비자원 의료피해구제 사례들의 일별-)

  • Kim, Kyoung Reay;Ahn, Bup-Young
    • The Korean Society of Law and Medicine
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    • v.13 no.2
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    • pp.179-214
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    • 2012
  • There are two opinions on the legal characteristics of damages for non-pecuniary loss, a private sanctions theory and complementary function of damages for non-pecuniary loss, briefly. There is a close connection between the legal characteristics and the function of damages for non-pecuniary loss. The functions of damages for non-pecuniary loss are consist of satisfaction, prevention( sanctions) and complementation. Several cases of medical injury relief reported to Korea Comsumer Agency are categorized as follows, 1) cases of death after having an operation, 2) diagnosed with disability after a medical accident, 3) extended damages happening related to delayed diagnosis, 4) et cetera(a plastic surgery, a treatment with oriental medicine), and the damages for non-pecuniary loss in respect to each cases are examined. In the case of occurring death or disability, Korea Comsumer Agency has set up guidelines for assessment of damages for non-pecuniary loss by classifying into major and collateral violation for a duty of care. Furthermore, the damages for non-pecuniary loss in the case of all sorts of cancers, are assessed in accordance with the degree of responsibility subsequent to dividing cancer into good and poor prognosis. When it comes to a complementary function of damages for non-pecuniary loss in the actual work, it is hard to assess the damages as it is difficult to objectify non-pecuniary loss, such as emotional distress. Though compensation for damages is major legal characteristics of consolation money, preventing a damage(private sanctions) through consolation for a victim or sanctions against an assailant also has great significance. Therefore, it is necessary to approach flexibly for mutual agreement by considering specialty( concrete facts) of individual issue thoroughly. If considering this aging society that limits the possible age for work to 60 years old, it is needed to have a complementary function of consolation money in mind not to make it less meaningful for victims due to small sum of consolation money.

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An Analysis of the Status of OER(Open Educational Resources) Usage in Asia (아시아지역의 공개교육자원 활용현황 분석)

  • Lee, Eunjung;Kim, Yong
    • Journal of Internet Computing and Services
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    • v.13 no.6
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    • pp.41-53
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    • 2012
  • Open educational resources(OER) enable the spread of mutual information exchange and provide advantages to both their users and institutions, such as reducing costs, improving content quality, and establishing relationships. The recent research on OER was about their connection to formal education, copyright trends, and corporate e-learning. There have been very few studies, however, on the utilization of OER and on the problems related to their practical use. Thus, this study was conducted for the purposes of analyzing the status of OER usage in education-related institutions and of providing suggestions for institution operation based on the analysis results, to promote the use of OER. A survey was conducted among more than 200 institutions in Asia, and the survey results showed that 'images and visual materials' are the most commonly used materials in Asia, and that the factors barring OER usage in the said region are 'lack of awareness', 'lack of skills', 'the absence of a reward system', and poor cooperation in participation. To promote OER usage, each institution should provide training courses about awareness, utilization skills, and copyrights. There is also a need to provide support for the establishment of reward systems and environments for OER usage. Finally, more active participation is required for inter-agency cooperation in OER sharing.

Evaluation of Shanghai New Port Development Plan (중국 상해 신항만 개발계획 평가)

  • Nam, Ki-Chan;Song, Yong-Seok;Yeon, Jeong-Hum
    • Journal of Korean Society of Transportation
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    • v.21 no.6
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    • pp.7-15
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    • 2003
  • China is expected to experience rapid increase in container traffic due to the joining to WTO and the fast economic growth. However, logistics-related infrastructure such as sea port is very poor and the capacity is lagging far behind the demand, resulting in transferring around 70% of import and export cargo volume at ports in adjoining countries such as Korea, Taiwan, Hong Kong and Japan. Recently, China announced a huge project of developing an offshore port consisting of 52 berths, 30km away from Shanghai with a connecting bridge. As such plan seems to have a significant impact on the port of Pusan which tries to be a Hub port in Far East Asia, we need to scrutinize the plan. This paper, therefore, tries to examine Shanghai New Port Plan, to evaluate the feasibility and potential competitiveness, and to analyze the impact on Pusan port. For this, we review the situation of major container ports in China and the flow pattern of container traffic to and from Pusan port. We then examine the feasibility of the proposed offshore port with respect to demand and supply for container terminal, weather condition, hinterland connection and resource of investment.

DENTAL CARIES TREATMENT IN FEEDING PROBLEM PATIENT WITH CONGENITAL ESOPHAGEAL ATRESIA : A CASE REPORT (선천성 식도폐쇄를 가진 식이장애 환아의 치아우식 치료 증례 보고)

  • Heo, Seon-Jae;Lee, Mi-Yeon;Shin, Teo Jeon;Hyun, Hong-Keun;Kim, Jung-Wook;Jang, Ki-Taeg;Lee, Sang-Hoon;Kim, Chong-Chul;Kim, Young-Jae
    • The Journal of Korea Assosiation for Disability and Oral Health
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    • v.12 no.1
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    • pp.6-10
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    • 2016
  • Esophageal atresia is the abnormal development of the esophagus that connects the mouth to the stomach. This birth defect results in the incomplete connection of the esophagus to the stomach causing an inability to swallow properly and breathing difficulties. Surgery is the only treatment for esophageal atresia. Patients undergone an esophageal reconstruction usually suffer from gastroesophageal reflex. A 5-year old boy with congenital esophageal atresia and Sciwitar syndrome visited Seoul National University Dental Hospital because generalized excessive loss of tooth structure. The patient had history of multiple operations for reconstruct esophagus. He had little food intake experience thought oral and had difficulty to swallowing. The patient was generalized severe erosive and decayed state. For patient, the dental procedure under general anesthesia was scheduled due to the multiple caries with erosion and poor cooperation. Under general anesthesia, pulpectomy and restoration as well as extraction was performed. Gastroesophageal reflex is potentially serious condition, with various extraesophageal adverse effects such as dental erosion. To prevent progression of dental caries, dietary counselling and oral hygiene instruction should be reinforced. Also, restorations to erosive teeth will maintain esthetics and function and preserve pulp vitality.