• Title/Summary/Keyword: Problem Space

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A Conceptual Design on Training Simulator of the Special Railway Vehicle for Multiple Tie Tamper (궤도보수 특수철도차량 탬퍼 모의훈련연습기의 개념설계)

  • Ahn, Seung-Ho;Kang, Jeong Hyung;Kim, Chul Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.10
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    • pp.430-436
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    • 2018
  • Special railway vehicles for track maintenance are equipped with a tamping device that adjusts various track trajectories to reduce the vibration of rolling stock and improve ride quality during trains passing over a track. The development of a simulator that can confirm the error of the actual tamping work is important for reducing human error in the linearization of the track misalignment. In this study, to improve the reality and training effect of conventional 2D simulator, 3D simulator modeling was implemented for tamping work of special railway vehicles in virtual space. The problem of buffering during high screen quality of tamping work was solved using the Unwrap UVW mapping technique of a low polygon extracted from high quality polygon modeling. The human error in the training of the tamping work was detected by the principle of circle and square collision when the tamping tyne and the sleeper collided. In addition, vibration of the driving chair was generated at the same time as the collision, and the number of the sleeper strikes is displayed on the simulator exercise screen. Owing to the scattering of railway ballast protruding from the sleepers, which had a serious effect on the safety of the vehicle, the gravel bouncing effect of the tamping unit was applied.

A Labeling Methods for Keyword Search over Large XML Documents (대용량 XML 문서의 키워드 검색을 위한 레이블링 기법)

  • Sun, Dong-Han;Hwang, Soo-Chan
    • Journal of KIISE
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    • v.41 no.9
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    • pp.699-706
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    • 2014
  • As XML documents are getting bigger and more complex, a keyword-based search method that does not require structural information is needed to search these large XML documents. In order to use this method, not only all keywords expressed as nodes in the XML document must be labeled for indexing but also structural information should be well represented. However, the existing labeling methods either have very simple information of XML documents for index or represent the structural information which is difficult to deal with the increase of XML documents' size. As the size of XML documents is getting larger, it causes either the poor performance of keyword search or the exponential increase of space usage. In this paper, we present the Repetitive Prime Labeling Scheme (RPLS) in order to improve the problem of the existing labeling methods for keyword-based search of large XML documents. This method is based on the existing prime number labeling method and allows a parent's prime number to be used at a lower level repeatedly so that the number of prime numbers being generated can be reduced. Then, we show an experimental result of the comparison between our methods and the existing methods.

A Design for the Symbol Park and the Waterfront Park for the Second Stage Development in the Eastern Rear Complex of Gwangyang Harbor (광양항 동측배후단지 2단계 사업지구 상징공원 및 수변공원 설계)

  • Hong Hyoung-Soon;Kim Do-Kyong;Jeong Han-Ho
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.3 s.116
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    • pp.104-119
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    • 2006
  • The eastern rear business complex of the Gwangyang Harbor (second stage) has undergone the 'alternative bid' process by which a construction company is selected based on their suggestions for an alternative plan and the bid for the construction expenses is based on the previously completed original plan, thereby implicitly accepting the arrangement and scale of the park which was presented in the original plan. It is possible, however, that the concept and plan of each park needs to be approached in a new way within the extent of given design guidelines. This study focuses on the alternative plan process and the Symbol Park (the second neighborhood park) and Waterfront Park (the third neighborhood park) among the five neighborhood parks in the eastern rear business complex (second stage). These two parks provide scale and function for the structure of the park and greenways system at the eastern rear complex. The neighboring waterway is a significant resource for emphasizing the pre-development features of the site. The alternative plan process focuses on determining the resources for the park's plan based on the environmental analyses of the site and utilizing the results. That is, through an analysis of the current state, all available resources are determined and the facilities and activities are derived based on these results. By this, Symbol Park and Waterfront Park reflect the regional features of the eastern rear complex, and these parks will feasibly perform the role of the region's key parte. The limit of this study is the fact that there is no chance for landscape architecture to actively play a role in the creation of the master plan, land utilization plan, and plan for the complex. Therefore there is a problem that the function scale and location of the park are not distributed appropriately in the rear complex. Also the plan for protecting the waterway's shore, a significant resource, only considers the structural stability of the engineering works, degrading the visual and ecological quality. These experiences will be used as a case for further designing the industrial complex and for the resulting park plan.

Theological Reflection on the Hope Found in Suffering: Focusing on the Book of Job and the Theology of J. Moltmann (고통 속에서 발견하는 희망에 대한 신학적 성찰 : 욥기와 몰트만 신학을 중심으로)

  • Im, Min Kyun
    • The Journal of the Korea Contents Association
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    • v.20 no.9
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    • pp.638-647
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    • 2020
  • This study reflects on suffering, a theme of anthropology, from a Christian theological point of hope. It suggests that suffering is not a negative experience, rather a medium of hope that can be a positive driving force in life and an opportunity to reach personal maturity. It aims to deepen the content of anthropology regarding the meaning of suffering by discovering a new harmony within the relationship between pain and hope. The book of Job denies the theodicical concept that justifies suffering as punishment for human sins and opens a new horizon of understanding the suffering as a space of hope, where men can experience the Love of God in the relationship with God. In his theology of suffering, Moltmann broadens and deepens the horizon of understanding as the book of Job discovered. First, he interprets the history in the hope of an eschatological future when the resurrected Jesus Christ will bring the final victory over evil and suffering. Then he invites men to proactively resist the absurdity and suffering revealed through this interpretation. Second, Moltmann reflects on the problem of suffering in the concept of the Trinity of God who endures active suffering with love for men shown in the crucifixion of Jesus Christ. He offers another hope that enables men to overcome the suffering in God's love. Therefore, the Christian faith can confess that we can hope in suffering.

A Numerical Study on the Performance Analysis of a Solar Air Heating System with Forced Circulation Method (강제순환 방식의 공기가열식 태양열 집열기의 성능분석에 관한 수치해석 연구)

  • Park, Hyeong-Su;Kim, Chul-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.122-126
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    • 2017
  • The aim of this study was to develop a device for solving the heating problem of living space using heated air, utilizing a simple air heater type collector for solar energy. At the present time, this study assessed the possibility of a development system through theoretical calculations for the amount of available energy according to the size change of the air-heated solar energy collector. To produce and supply hot water using the heat energy of the sun, hot water at $100^{\circ}C$ or less was produced using a flat or vacuum tube type collector. The purpose of this study was to research the air heating type solar collector that utilizes heating energy with heating air above $75^{\circ}C$, by designing and manufacturing an air piping type solar collector that is a simpler type than a conventional solar collector system. The analysis results were obtained for the generated air temperature ($^{\circ}C$) and the production of air (kg/h) to determine the performance of air heating by an air-heated solar collector according to the heat transfer characteristics in the collector of the model when a specified amount of heat flux was dropped into a solar collector of a certain size using PHOENICS, which is a heat flow analysis program applying the Finite Volume Method. From the analysis result, the temperature of the air obtained was approximately $40.5^{\circ}C$, which could be heated using an air heating tube with an inner diameter of 0.1m made of aluminum in a collector with a size of $1.2m{\times}1.1m{\times}0.19m$. The production of air was approximately 161 m3/h. This device can be applied to maintain a suitable environment for human activity using the heat energy of the sun.

An automated memory error detection technique using source code analysis in C programs (C언어 기반 프로그램의 소스코드 분석을 이용한 메모리 접근오류 자동검출 기법)

  • Cho, Dae-Wan;Oh, Seung-Uk;Kim, Hyeon-Soo
    • The KIPS Transactions:PartD
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    • v.14D no.6
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    • pp.675-688
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    • 2007
  • Memory access errors are frequently occurred in C programs. A number of tools and research works have been trying to detect the errors automatically. However, they have one or more of the following problems: inability to detect all memory errors, changing the memory allocation mechanism, incompatibility with libraries, and excessive performance overhead. In this paper, we suggest a new method to solve these problems, and then present a result of comparison to the previous research works through the experiments. Our approach consists of two phases. First is to transform source code at compile time through inserting instrumentation into the source code. And second is to detect memory errors at run time with a bitmap that maintains information about memory allocation. Our approach has improved the error detection abilities against the binary code analysis based ones by using the source code analysis technique, and enhanced performance in terms of both space and time, too. In addition, our approach has no problem with respect to compatibility with shared libraries as well as does not need to modify memory allocation mechanism.

Behcet`s Syndrome with Aortic Aneurysm: A Case Report (Bechet`s 병과 합병된 상부대동맥류: 치험 1례 보고)

  • Gang, Jeong-Ho;Lee, Jeong-Ho;Yu, Hoe-Seong
    • Journal of Chest Surgery
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    • v.10 no.1
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    • pp.98-105
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    • 1977
  • A 36 year old blindman, engineer was admitted with chief complaints of hemoptysis, recurrent sore throat, pyoderma in genital organ, uveitis and thrombophlebitis for 10 years. Above the chief complaints were remission or exacerbation during hospitalization. Physicalexamination showed that left radial, ulnar & brachial pulse was not palpable. No bruit or murmur was obtained over the mass. Neurologic examination revealed no significant finding.On admission, chest P-A showed hen egg sized round & oval compact hazy density on left upper lung field. Bronchogram revealed no pathological finding and Lt. tomogram showed well define large,ovoid mass density in the superior mediastinum. Fluoroscopy finding showed nonpulsatile on left upper lung field. Pre-op. aortography was not taken, under the impression of lung Ca. rule out .sortie aneurysm, exploratory operation was performed through the 2nd intercostal space, Lt. It was performed that the mass was ascending sortie aneurysm of saccular type. Direct aneurysmectomy with multiple figure of eight suture were done without any prosthetic graft. Post-op. control I.V.C graphy showed completely obstruction sign. Postopcontrol aortography revealed good surgical result. Final, histopathological answered non-specific sortie aneurysm, saccular type. Post-op. courses were uneventful except mild neurologic disturbance with subclavian steal syndrome and associated with both lower leg pitting edema due to inferior vena cava obstruction. After op, 3 month later, discharged to home, with big systemic problem. Behcet`s syndrome reviewed with related literatures. The coexistence of mouth and genital ulceration with hypopyon mentioned by hippocrates and described by various workers in the early part of this century was first defined as a syndrome by Behcet in 1937. In 1937 Behcet described a chronic relapsing triple symptom complex of oral ulceration, genital ulceration, and ocular inflammation. The place of the syndrome as part of a systemic disorder in now clearer, and the under lying pathology appears to be a vasculitis. The disease runs a- chronic course, blindness being the greatest disability and control nervous system involvement a cause of death. Thrombophlebitis is fairly frequent, france et al [1951] giving an incidence of 25% and Dowling [1961] 12%, superficial thrombophlebitis migrans and thrombosis of large veins, including venae cavae [Thomas, 1947: Boolukos 1960] are recorded. Little attention has been paid to arterial involvement. Mishima et al. [1961] described resection cf an aortic aneurysm in a 38 year old man with Behcet`s syndorme. Mounsey in a clinicopathological conference described a case [Brit, med. J., 1966] of ruptured aortic aneurysm in Bechcet`s syndrome treated by aorto-iliac graft. Also, Shikano and Oshima et al [1963] recorded two aneyrysm of smaller arteries. Unfrequently, aortic aneurysm was presumed to be secondary to osteomyelitis of the lumber spine, though the possible association between aortic aneurysm and Behcet`s syndrome was raised. A further case is reported here, in which ascending aortic aneurysm with Behcet`s Ds. appeared to form part of this generalized disease. This is a case report of surgical experience of Behcet`s Ds. with ascending aortic aneurysm which had nearly all the typical clinical features. Above mentioned and was reviewed with related literatures.

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Analytical Determination of Optimal Transit Stop Spacing (최적 정류장 간격의 해석적 연구)

  • Park, Jun-Sik;Go, Seung-Yeong;Lee, Cheong-Won;Kim, Jeom-San
    • Journal of Korean Society of Transportation
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    • v.25 no.3
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    • pp.145-154
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    • 2007
  • Determining stop spacing is a very important process in transit system planning. This study is involved in an analytical approach to decide the transit stop spacing. Transit stop spacing should be longer as 1) user access speed, 2) user travel time, and 3) dwell time increase, and shorter as 1) passengers (boardings and alightings) and 2) headway increase. In this study, a methodology is proposed to determine transit stop spacing to minimize total cost (user cost plus operator cost) with irregular passenger distribution (boardings and alightings) Without considering in-vehicle passengers, the transit stop spacing should be shorter in the concentrated sections of the passenger distribution than in others to minimize total cost. Through the conceptual analysis, it is verified that the transit stop spacing could be longer as the in-vehicle passengers increase in certain sections. This study proposes a simple practical method to determine transit stop spacing and locations instead of a dynamic programming method which generally includes a complex and difficult calculation. If the space axis is changed to a time axis. the methodology of this study could be expanded to analyze a solution for the transit service (or headway) schedule problem.

Generation of Multi-view Images Using Depth Map Decomposition and Edge Smoothing (깊이맵의 정보 분해와 경계 평탄 필터링을 이용한 다시점 영상 생성 방법)

  • Kim, Sung-Yeol;Lee, Sang-Beom;Kim, Yoo-Kyung;Ho, Yo-Sung
    • Journal of Broadcast Engineering
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    • v.11 no.4 s.33
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    • pp.471-482
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    • 2006
  • In this paper, we propose a new scheme to generate multi-view images utilizing depth map decomposition and adaptive edge smoothing. After carrying out smooth filtering based on an adaptive window size to regions of edges in the depth map, we decompose the smoothed depth map into four types of images: regular mesh, object boundary, feature point, and number-of-layer images. Then, we generate 3-D scenes from the decomposed images using a 3-D mesh triangulation technique. Finally, we extract multi-view images from the reconstructed 3-D scenes by changing the position of a virtual camera in the 3-D space. Experimental results show that our scheme generates multi-view images successfully by minimizing a rubber-sheet problem using edge smoothing, and renders consecutive 3-D scenes in real time through information decomposition of depth maps. In addition, the proposed scheme can be used for 3-D applications that need the depth information, such as depth keying, since we can preserve the depth data unlike the previous unsymmetric filtering method.

Development of Base Concrete Block for Quiet Pavement System (저소음 포장용 기층 콘크리트 블록 개발)

  • Lee, Kwan-Ho;Park, Woo-Jin;Kim, Kwang-Yeom
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.1
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    • pp.35-42
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    • 2010
  • The rapid economic development induced the massive road constructions, becoming bigger and high-speed of the vehicles. However, it brings lots of social problems, such as air pollutions, traffic noise and vibration. Special concrete block for the base course of asphalt pavement is needed to decrease traffic noise such as tire's explosive and vehicles sound, applying Helmholtz Resonators theory to asphalt pavement. If it is applied to the area where it happens considerable noise such as a junction, the street of a housing complex and a residential street, it is one of considerable method to solve the social requirements of noise problem. This research examines couple of laboratory tests for the sound absorption effect of the concrete block and the base concrete block. There are specimens which is fixed hall-size, space, depth as the condition of this research, and these are analysed of noise decrease effect using different condition of the first noise of each vehicle. As a result of analysis data according to vehicle noise volume, measurement distance, a form and size of the hall using the base concrete block, the use of special concrete base showed a good alternative solution for decreasing traffic noise level, from 4 dB to 9 dB.