• Earthquakes and Structures
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• v.19 no.5
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• pp.315-329
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• 2020

Through bolt connections in Concrete Filled Steel Tubes (CFSTs) has been proved to be good in terms of seismic performance and constructability. Stiffened extended end plate connection with full through type bolt helps to avoid field weld altogether, and hence to improve the quality of joints. An experimental study was conducted on the hysteretic performance of square interior beam-column connections using flat extended end plates with through bolt. The study focuses on the effect of the bond between the tie rod and the core concrete on the cyclic performance of the joint. The study also quantifies how much the interior joint is getting strengthened due to the confinement effect induced by bi-directional bolting, which is widely used in 3D moment resisting frames. For a better understanding of the mechanism and for the prediction of shear capacity of the panel zone, a mathematical model was generated. The various parameters included in the model are the influence of axial load, amount of prestress induced by bolt tightening, anchorage, and the concrete strut action. The study investigates the strength, stiffness, ductility, and energy dissipation characteristics. The results indicate that the seismic resistance is at par with American Institute of Steel Construction (AISC) seismic recommendations. The bidirectional bolting and bond effect have got remarkable influence on the performance of joints.

• The Journal of the Acoustical Society of Korea
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• v.28 no.1E
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• pp.23-28
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• 2009

At the crossings of turnout systems, noise is generated by the impact of train on the connection points. However, rapid movement changes between rail and wheels on connection point are inevitable on existing turnout section which may cause safety concern as well as noise problem caused by repeated impact load by passing train. And given the turnout is a complicated system which combines various functions such as rolling stock, trackbed, signaling, communication and electrical system, it's very difficult to expect to improve the overall performance of the turnout in such a way of optimizing only particular part of such integrated system. Since the turnout is the only movable section among the integrated parts and has complicated structure that inevitably brings about quick and sudden movement, safety has been still put on the top of the list. This study was aimed at comparing and analyzing the noise data obtained around the turnout of existing railway, by categorizing them into tilting train, high speed train and traditional train, and by distance, speed and type of turnout. And based on the data measured, the forecast of noise level when tilting train accelerates around a turnout was conducted in the study.

• Journal of Chest Surgery
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• v.38 no.7 s.252
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• pp.510-513
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• 2005

Anomalous systemic arterial supply to the normal basal segments with normal bronchial connection of the lung without sequestration is a rare anomaly. It was classified as a type of sequestration according to Pryce's terminology, but whether the term - one of the sequestration is appropriate or not, is controversial because of normal bronchial connection. We describe our experience with surgical treatments for anomalous arterial supply to the normal basal segments of the left lower lobe.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.679-687
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• 2013

Although stable and safe drinking water supply to the customers is a basic function of multi-regional water supply systems in Korea, most systems have their vulnerabilities in emergency time due to the branch-type. Application of connections from the other water supply system can provide a solutions for these tentative problems. This paper describes reduction planning of water supply accidents that can minimize a service interruption to customers in multi-regional water supply system by connecting pipe lines between local water supply systems in Mokpo city areas. The result of this study shows that Juam dam multi-regional water supply systems can cover all of the water shortage in southern parts of Jeonnam multi-regional water supply systems by transmitting water through connected pipes between local networks. This can be effective to supply water interactively in various contingencies, when a pipe line accident occurs in southern area of Jeonnam multi-regional water supply systems. On the contrary, southern area of Jeonnam multi-regional water supply systems can cover 99.5 %($62,500m^3/day$) of the water shortage of Juam dam multi-regional water supply systems when service interruptions caused by various pipe accidents occur in the system.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.1
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• pp.49-54
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• 1995

Three types of floating-type automatic inlet were developed for the purpose of reduc- ing farmer's working hours required for water management and saving irrigation water. The point of automation is to use a float within the inlet which is floated and sinked by the ponding depth of paddy field, Thus opens and closes the control gate of irrigation. Suitability of each inlet may depend on production cost, applicability to paddy field condi- tions, and feasibility to farmers, etc. The first model was composed of three parts : chamber for irrigation control gate, chamber for float controlled by ponding depth, and connection bar between the two parts. It was designed to open and close the control gate gradually as the ponding depth drops and rises to a certain level. The second model was designed to improve the weak point of the first model which is the imperfect-closing of gate when it approaches to the end of ir- rigation. A switch-spring was equipped above the connection bar for perfect opening and closing of gate when the ponding depth reaches to a certain level. The third model was designed by combining the two chambers, that is, cut in halves the inlet volume of the above two models. Magnets were equipped above the float for perfect opening and closing gate. The functional experiment for three developed inlets was successfully carried out and the rating curves were derived.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10B
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• pp.1665-1674
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• 2000

This paper treats the interworking of LAN-based networks like TCP over the ATM protocol stack in an ATM multicast session. Multicast connection will cause CIP since multicast group members form a connection tree by some tree methods and share the connected tree. The paper solve the CIP problem through a block-by-block transmission using ABT/IT method. ABT/IT RM cell is modified and block scheduling algorithm considering the traffic types is applied to each ATM switch using the enhanced RM cell. Block scheduling algorithm will avoid the indiscriminate discard of UBR traffic when congestion occurs and it can provide an efficient and fair service. The paper builds a block scheduler system and suggests the block scheduling algorithm for a multicast session in an ATM switch. UBR traffics arriving at the switch trough each VC is classified by the traffic type and stored at class buffer and thereafter indisciminately transmitted. When block scheduling algorithm is applied it will improve the UBR traffic performance such as end-to-end delay cell block loss ration etc. This paper evaluated the performance of block scheduling algorithm through the simulation using the C language and data structure.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.2
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• pp.102-108
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• 2002

This paper describes the overvoltage analysis and reduction methods of insulation joint boxes in underground transmission power cables when direct lightning surge strikes to overhead transmission line. An actual 154kV combined transmission line with underground Power cables was modelled in ATPDraw for simulation. Simulations were performed to analyze the overvoltage between insulation joint boxes, sheath-to-ground voltage according to the distance between cable conductors, cable lengths, burying types, CCPU connection types. The most effective method to reduce the induced overvoltage of Insulation joint boxes was proposed. It is evaluated that the proposed reduction method riven from the detailed simulations can be effectively applied to the actual underground power cable systems.

• Steel and Composite Structures
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• v.19 no.6
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• pp.1381-1402
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• 2015

The application of composite steel-concrete slabs with profiled steel sheeting has increased, due to the various advantages in relation to reinforced concrete slabs such as, the reduced thickness, the reduced amount of lost formwork needed, as well as the speed of execution. The loss of longitudinal shear resistance is, generally, the governing design mode for simply supported spans of common lengths. For common distributed loadings, the composite behaviour is influenced by the partial shear connection between the concrete and the steel sheeting. The present research work is intended to contribute to improving the ultimate limit state behaviour of composite slabs using end anchorage. Eurocode 4, Part 1.1 (EN 1994-1-1) provides an analytical methodology for predicting the increase of longitudinal resistance, achieved by using shear studs welded through the steel sheeting as the end anchorage mechanism. The code does not supply an analytical methodology for other kinds of end anchorage so, additional tests or studies are needed to prove the effectiveness of these types of anchorage. The influence of end anchorage mechanisms provided by transverse rebars at the ends of simply supported composite slabs is analysed in this paper. Two experimental programmes were carried out, the first to determine the resistance provided by the new end anchorage mechanism and the second to analyse its influence on the behaviour of simply supported composite slabs.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.61-62
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• 2011

비닐하우스는 매우 세장한 강관부재들을 교차 결합하여 조립한 철골 구조물의 한 종류이다. 현행 설계기준으로 단동 비닐하우스의 최대 구조성능은 풍하중 40m/s, 설하중 50cm에 달한다. 그러나 설계 단계에서는 부재들의 교차결합 특성 및 부재가 직접 지반에 삽입되는 기초의 특성이 적합하게 반영되지 않는 문제점이 있다. 따라서 가력시험을 통하여 반강접 특성을 갖는 부재 교차부 및 지반삽입기초 조건이 구조물의 거동에 미치는 영향을 분석하였다. 부재 교차부가 강접 조건일 경우와 비교하여 교차부가 반강접일 경우에는 재하지점의 수평강성이 최대 54% 작게 나타났으나 주변 교차절점들에서의 에너지 흡수로 인하여 재하지점과 수평으로 3m 떨어진 지점에서는 반대로 최대 39% 큰 값을 보였다. 지반삽입기초의 경우에는 고정조건과 비교하여 재하지점의 수평강성이 최대 32% 작게 나타났으며, 지점부에서는 기초 조건의 영향으로 최대 26%의 휨강성 증가 효과를 보였다. 부재 교차부와 기초 조건이 구조물의 정적거동에 미치는 영향을 확인하였으나 최대내력과 강성 산정을 통한 구조성능 평가 방법의 개발이 필요할 것으로 판단된다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1669-1674
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• 2017

In this study, We have discussed the development of a diagnostic device to detect and prevent electrical fire due to the arc caused by contact failure and partial disconnection at the connection part of the three-phase electric heater wiring used in the industrial field. The arc caused by contact failure and partial disconnection at the connection part of the electric heater shows a change in the current effective value. Therefore, it is possible to determine whether there exists a defect by analyzing the current unbalance factor and the number of current fluctuations with the diagnostic apparatus. The three-phase unbalanced heater is considered to be capable of determining defects through periodic measurement and trend analysis of the current unbalance factor. It is also expected that this device can be used not only for electric heaters but also for detection of defects in wiring and connections of electrical equipment having a characteristic of constant load current.