열유도상분리법에 의한 미세다공성 폴리에틸렌 중공사막의 제조에 관한 연구

지동선,공용운 단국대학교 1999 산업기술연구 Vol.1 No.-

The solid-liquid phase separation of the high density polyethylene(HDPE) hollow fiber membrane prepared via thermally induced phase separation process was thermodynamically investigated. As the amount of liquid paraffin(LP) used as a diluent increased, the equilibrium melting temperature given Hoffman-Weeks plots decreased. The value of Flory-Huggins interaction parameter obtained from the melting point depression in the HDPE/LP blends was -0.43. The phase was not separated in the melt state since it had good miscibility. However, the solid-liquid phase separation occurred at lower temperatures. The temperatures of crystallization and phase separation decreased with increase in the cooling rate. As the amount of liquid paraffin and draft ratio increased, the flux of polyethylene hollow fiber membrane increased. It was found that the optimum blend ratio for microporous polyethylene hollow fiber membrane of HDPE/LP blends was determined to be 40/60. The flux of polyethylene glycol solution under the same applied pressure and time was less than that of pure water for HDPE/LP 40/60 and 50/50(wt%).

자바 애플릿을 사용한 웹 기반 C컴파일 시스템

최순관,김동식,공용해 순천향대학교 부설 산업기술연구소 2004 순천향 산업기술연구소논문집 Vol.10 No.2

웹을 이용하면 전 세계 어디라도 연결할 수 있고, 원하는 정보 또한 쉽게 제공받을 수 있다. 이러한 웹의 장접을 이용하여 다양한 교육용 콘텐츠가 개발되어지고 있다. 본 연구는 C언어 학습 콘텐츠를 개발중 값비싼 C 컴파일러를 구매하지 않고 쉽게 실습할 수 있는 방법으로, 클라이언트에 제한적으로 실행되어지는 C 컴파일러를 인터넷에서 이용하게 한 연구로 LINUX 기반의 서버측 C 컴파일러를 이용하여 프로그램을 작성 실행시켜 보는 시스템을 개발하였다. 구현된 시스템은 상용의 컴파일러를 구매하지 않아도 되는 경제적인 장점을 가진다.

JDBC를 이용한 Web-GIS 구현

전홍구,최관순,공용해 순천향대학교 부설 산업기술연구소 1999 순천향 산업기술연구소논문집 Vol.5 No.2

GIS is evolving from a technology that addresses specific applications to a broad-based information system. Its value goes beyond increased efficiency, cost savings. Therefor GIS will be fundamental to the future on the internet. But our organizations and societies exclusively handle geographic informations in Korea. and they use independently foregin commercial GIS softwares. It makses difficult to accmulate local techniques in GIS. In order to solve this problem we implement WEB-GIS using JDBC without depening specific software.

지하철 3호선 동호철교 하로판형교 구간 콘크리트도상화개량 시공 사례

공선용(Kong Sun-Yong),이규천(Lee Gyu-Chon),김상진(Kim Sang-Jin) 한국철도학회 2006 한국철도학회 학술발표대회논문집 Vol.- No.-

In this report, we introduce the design criteria, construction case and performance of our track improvement project from ballasted track to concrete track on the example section of Dong-Ho Bridge (girder-plate type bridge) in Seoul Metro Line No. 3, after monitoring 3 years which is from Dec. 2002. 15-year-old Dong-Ho Bridge"s ballast was crushed, worn away, reduced track absorption, had draining problems from the crushed ballast, and corrosion was progressing in steel bridge because the waterproof underneath track was partially damaged. So, we applied changing the track on bridge area from ballasted to concrete in order to keep the track watertight and improve durability of bridge by reducing its weight. This investigation is based on the design criteria and construction case of the concrete track on the girder-type bridge in operating line. We explain the main design, materials, and other performance results in detail and hope it to be helpful for the track improvement in operating line.

콘크리트 궤도의 최적 탄성에 관한 연구

공선용(Kong Sun-Yong),김상진(Kim Sang-JIn) 한국철도학회 2007 한국철도학회 학술발표대회논문집 Vol.- No.-

In recent railway construction, the concrete slab track is getting highlighted as main stream in track type. However, it is the fact that there are different opinions in selection of the optimized spring coefficient of elastic pad. In this study, the performance of vibration reduction in different stiffness of rail pad for ballasted track was compared, and the changes in characteristics, such as static/dynamic deflection of components, vibration acceleration, insertion loss etc., were analysed by using ISI Program for various types of rail fastening system used in concrete slab track. It was concluded that the fastening system with softer pads has shown the better performance of vibration reduction in concrete slab track and the optimized static stiffness has been calculated to 21.1kN/㎜ for conventional railways, 17.6kN/㎜ for high-speed railways and 17.8kN/㎜ for subways.

현장측정을 통한 노후 레일의 피로수명 평가에 관한 연구

공선용(Kong Sun-Yong),성덕룡(Sung Deok-Yong),김준형(Kim Jun-Hyung),박용걸(Park Yong-Gul) 한국철도학회 2007 한국철도학회 학술발표대회논문집 Vol.- No.-

It is essential to reduce track maintenance costs and to extend the periodic replacements of continuous welded rails based on accumulated passing tonnage. As recently train load decrease and rail joints wear down less, the periodic replacements of continuous welded rails can be extended. There are many kinds of rail damage like squat, head-check and corrugation. These can be taken nondestructive or naked eye test. So the periodic replacements of continuous welded rails based on accumulated passing tonnage were examine with focusing on a crack of rail bottom of continuous welded rail. Therefore, this study measure dynamic response of track by metro train load, it compute impact coefficient and track spring coefficient for estimating a condition of actual track system. Also, it is converted the measured stress waveform into stress frequency histogram by the rain-flow counting methods, and then the equivalence of stress is calculated. As apply s-n curve of a new welded rail, accumulated fatigue damage ratio of laid rail and remaining service lives is estimated. This study suggest a plan of the periodic replacements of continuous welded rails based on accumulated passing tonnage classified by the types of track system.

서울지하철 4호선 R250m 인접구간 도시개발정비에 따른 궤도방진설계

공선용(Kong Sun-Yong),김상진(Kim Sang-Jin),양태경(Yang Tae-Kyung),백찬호(Baik Chan-Ho) 한국철도학회 2010 한국철도학회 학술발표대회논문집 Vol.2010 No.7

The surroundings around subway are becoming more lively for project of CBD (an redevelopment project), however vibrations which are made through passing train cold spread buildings around. The structure-borne noise could be generated at the same time that makes people including developers and th citizens have negative viewpoint on railway. Especially, Seoul Metro 1-4 lines ar built alongside the road nearby houses and business district. That could make plenty of public resentments because of the structure-borne noise. Seoul Metro should make active alternative plans for their future urban environment projects which will be conducted. The case was Railway Facility which were conducted to minimize structure-borne noise from sharp curved track section (4 line, Sinyongsan~Ichon, R 250m). The section is adjacent to house district as near as 6.6m related with pusing international city project, the 4th urban environment project around international building, near Yongsan station. The interval of sleepers would be downsized in half with breaking existing case, and pad stiffness is reduced 4 ton from 10 ton. That makes structure-borne noise minimized because of vibrations are lowered about 19.1-23.0db. The structure above has remained for a year and a half from October, 2008, and had not any trouble to perform excellence with 80million ton rail accumulated tonnage.

레일지지계수 및 축중 변화에 따른 B2S판넬의 최적두께 산정

공선용(Kong Sun-Yong),김상진(Kim Sang-Jin),백찬호(Baik Chan-Ho) 한국철도학회 2009 한국철도학회 학술발표대회논문집 Vol.2009 No.11월

Most of Domestic railroads was composed of the ballast track that had an advantage of LCC (Life Cycle Cost) and it was constantly developed with the railroad materials such as a fastening components. Recently, it also has turning point to the concrete slab tracks that improve the driving stability. As the concrete tracks are planned, the Rail Level is regarded as an important factor on the construction expense. Although the Rail Level becomes lower than before that is to be stable enough for vehicle operating with technological development. Because of the B2S features that used a precast panel, estimation of its optimum thickness is also important factor for not only expense but also efficiency during mortar construction to the bottom layer of panel. This paper presents to calculate the optimum thickness of B2S panel according to various axle loads and rail support stiffness, and to evaluate the applicability. It also analyzes the effect from train loads to track by the 3D model, when the various rail support stiffness is applied for axle loads such as subway, light rail transit, railroad for convention line. As a result, it was evaluated that applicability of B2S slab track related to the conclusion for 2 types of railroads of other operating condition. And it should be used for the improvement of existing and construction railroads and tried to secure the basic data for structural safety and optimal track design.

서울메트로 1~4호선 고가역(창동역) 고체소음 저감 사례

공선용(Kong Sun-Yong),오희완(Oh Hee-Wan),김상진(Kim Sang-Jin) 한국철도학회 2007 한국철도학회 학술발표대회논문집 Vol.- No.-

In the recent railway construction, the concrete slab track is highlighted as the maintenance-free track and the main stream is moving from ballasted track to concrete slab track. However, in spite of many merits of concrete slab track, the higher noise generated from the concrete slab track is a troublesome question to solve and, by this reason, many studies on noise reduction of concrete slab track are carried out. The railway noise can be classified into the reflection noise emitted from wheel/rail contact and the structure-borne noise transmitted through railway structures. In this presentation, we would like to introduce an example of the successful reduction of structure-borne noise at track retrofitting to maintenance-free concrete slab track in elevated Changdong Station which was built with ballasted track on Rahmen structure.

급곡선용 레일탄성체결장치를 사용한 생력화궤도 시공 사례

공선용(Kong Sun-Yong),김상진(Kim Sang-Jin) 한국철도학회 2005 한국철도학회 학술발표대회논문집 Vol.- No.-

SMSC(Seoul Metropolitan Subway Corporation) is substantially taking the core role of mass transit system in Seoul Metropolitan area. When it was built, the design had challenged to sharp curved tracks less than 250m radius considering the protection of buildings and cultural properties as well as the connection to ground roads. Such circumstances have required a certain extent of slack in track geometry and therefore led to the construction of ballasted track with wooden sleepers. However, the dynamic force from running on sharp curved track has caused the misalignment and abnormal failure of track geometry, and it has resulted in a frequent maintenance and repair works which require a lot of cost and manpower. In this paper, we present the construction case of maintenance-free track system by using of concrete sleeper and elastic rail fastening system to ensure the safety of both passengers and trains, and to contribute the effective maintenance for track facilities of SMSC.