• Title/Summary/Keyword: Lee Sangho

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Probabilistic Approach on Railway Infrastructure Stability and Settlement Analysis

  • Lee, Sangho
    • International Journal of Railway
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    • v.6 no.2
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    • pp.45-52
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    • 2013
  • Railway construction needs vast soil investigation for its infrastructure foundation designs along the planned railway path to identify the design parameters for stability and serviceability checks. The soil investigation data are usually classified and grouped to decide design input parameters per each construction section and budget estimates. Deterministic design method which most civil engineer and practitioner are familiar with has a clear limitation in construction/maintenance budget control, and occasionally produced overdesigned or unsafe design problems. Instead of using a batch type analysis with predetermined input parameters, data population collected from site soil investigation and design load condition can be statistically estimated for the mean and variance to present the feature of data distribution and optimized with a best fitting probability function. Probabilistic approach using entire feature of design input data enables to predict the worst, best and most probable cases based on identified ranges of soil and load data, which will help railway designer select construction method to save the time and cost. This paper introduces two Monte Carlo simulations actually applied on estimation of retaining wall external stability and long term settlement of organic soil in soil investigation area for a recent high speed railway project.

Study of Implementation of Environment Data on a Smart Phone by Using Ubiquitous Radio Sensors (유비쿼터스 무선센서에 의한 실시간 환경데이터의 스마트폰 구현에 관한 연구)

  • Lee, Youngwook;Yeon, Sangho
    • Proceedings of the Korea Contents Association Conference
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    • 2012.05a
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    • pp.163-164
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    • 2012
  • 건설현장의 온도, 습도, GPS 위치정보 및 대기 중의 CO2 농도 등의 환경 데이터는 현장 건설공정의 진행사항에 따라 확인이나 설계 변경 또는 개선 등에 활용할 수 있다. 유비쿼터스 무선 센서들을 이용하여 건설현장의 환경데이터들을 용이하게 실시간으로 측정하고 언제 어느 곳에서든지 받아 볼 수 있도록 요즈음 많이 사용하는 스마트폰 상에 구현하였다. 따라서, 현장의 확인없이 현황을 파악할 수 있고 공정의 설계변경 또는 개선 등에 도움을 줄 수 있다. 특히 공사현장이 먼 거리에 떨어져 있을수록 더욱 유용하게 적용될 수 있을 것이다.

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The study Alarm & Auto Locking System of Electric Wire Compressor (경보음 발생 및 자동Locking 장치형 전선압축기에 대한 연구)

  • Choi Myeongho;Lee Sangho;Kim Dongmyung
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.800-802
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    • 2004
  • When an accident is happen due to using a bad Wire Compressor, some public resentments are caused and It cause lawsuit for we. In case, we will undergo a colossal financial loss. in addition to, Guide to improve quality of operation by using the number of times of pressing and pressing pressure with cooperative private enterprise. And because of needs for Thermal, Electrical and Chemical factor analysis of connection point of sleeve, expect to try improving problems of wire presser whole our company. We expect that reduce fault and save cost by this process. Consequently, we will prevent power losing and black out due to line faults by expulsion of inferiority equipment and prevent heating and line fault. This is possible using Alarming and Auto Locking Wire Compressor that is improve on this study.

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Rotating Reverse Osmosis Membrane Filtration (회전 역삼투 분리막 여과)

  • Sangho Lee;Richard M. Lueptow
    • Membrane Journal
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    • v.13 no.3
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    • pp.131-142
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    • 2003
  • Cylindrical rotating reverse osmosis (RO) is a means of dynamic filtration that incorporates both high shear and flow instabilities to reduce membrane fouling. This article summarizes recent works on rotating RO including the physics of rotating filtration; mass - transfer and concentration polarization; theoretical and experimental analysis; and some case studies.

A Study of an Android Application implementation for Real-Time Streaming Service (안드로이드를 기반으로 한 실시간 스트리밍에 대한 연구)

  • Lee, Sangho;Choi, Yuseong;Park, Jongbin;Kim, Myungho;Kim, Youngjong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.05a
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    • pp.316-319
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    • 2019
  • In this paper, the streaming architecture is designed by analyzing the existing real-time streaming platform, and the real-time communication and media storage are handled by accommodating multiple users. Furthermore, the Android mobile app allows users to test their behavior and provide services for deployment.

Development of a Parameter Estimation Support System for SWMM 5 (SWMM 5의 매개변수 추정지원 시스템 개발)

  • Jung, Tae Hun;Lee, Sangho
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.529-533
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    • 2016
  • 미국 환경청의 SWMM 5(storm water management model 5)는 유역의 홍수유출 모의 및 연속 유출 모의를 할 수 있는 모형으로서 국내뿐만 아니라 세계적으로 많이 사용되고 있는 모형이다. SWMM 5와 같은 유역 유출모형에서 결과의 적절성을 향상시키기 위해서는 모형에 사용되는 매개변수를 올바르게 추정할 필요가 있다. 하지만, 외국의 정교한 유역 유출모형들이 우리나라에서 제대로 적용되고 있지 못하는 이유 중 하나는 적절한 매개변수의 추정이 이루어지지 못하고 있는 점이다. 이러한 문제를 해결하고자 SWMM 5의 매개변수 추정 지원 시스템을 개발하였다. SWMM 5의 매개변수 추정지원 시스템은 민감도 분석, 최적화 기법에 의한 모형 자동보정, 매개변수 할당 및 도움 모듈로 이루어져 있다. SWMM 5의 매개변수 추정 지원 시스템에 사용되는 최적화 기법은 전역최적화 기법 중 하나인 SCE-UA(shuffled complex evolution-University of Arizona) 이다. SWMM 5의 매개변수 추정 지원 시스템의 개발은 국내 수자원 기술자들의 SWMM 5에 대한 이해 및 활용도를 더욱 향상시켜줄 것으로 기대한다.

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Analysis of thermal energy efficiency for hollow fiber membranes in direct contact membrane distillation

  • Park, Youngkyu;Lee, Sangho
    • Environmental Engineering Research
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    • v.24 no.2
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    • pp.347-353
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    • 2019
  • Although membrane distillation (MD) has great promise for desalination of saline water sources, it is crucial to improve its thermal efficiency to reduce the operating cost. Accordingly, this study intended to examine the thermal energy efficiency of MD modules in a pilot scale system. Two different modules of hollow fiber membranes were compared in direct contact MD mode. One of them was made of polypropylene with the effective membrane area of $2.6m^2$ and the other was made of polyvinylidene fluoride with the effective membrane area of $7.6m^2$. The influence of operation parameters, including the temperatures of feed and distillate, feed flow rate, and distillate flow rate on the flux, recovery, and performance ratio (PR), was investigated. Results showed that the two MD membranes showed different flux and PR values even under similar conditions. Moreover, both flow rate and temperature difference between feed and distillate significantly affect the PR values. These results suggest that the operating conditions for MD should be determined by considering the module properties.

Evaluation System for Defense IT Project in Korea: Post-Implementation Stage

  • Lee, Sangho;Song, Chong-Hyun
    • Journal of Multimedia Information System
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    • v.5 no.4
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    • pp.291-297
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    • 2018
  • Performance measurement is not an easy task. However, it is necessary to measure the expected value of the informatization project to be invested, to help the successful progress of the informatization project, and to confirm the result of the informatization project. This study describes the evaluation systems of the defense informatization project in Korea used after the end of the informatization project (post-implementation evaluation stage). In the post-implementation evaluation stage of proposed system, the informatization project is evaluated in terms of performance achievement, project plan compliance, project management, and economic validity. For each element, this study suggests metrics and practical measurement method. With metrics and their method, it can be evaluated which project is better than others. Moreover, the lessons learned can be developed. Under scarce budget condition, defense organizations can make better performance from IT project with the evaluation system suggested in this study.

A Symmetric Key Cryptography Algorithm by Using 3-Dimensional Matrix of Magic Squares

  • Lee, Sangho;Kim, Shiho;Jung, Kwangho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2013.11a
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    • pp.768-770
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    • 2013
  • We propose a symmetric key based cryptography algorithm to encode and decode the text data with limited length using 3-dimensional magic square matrix. To encode the plain text message, input text will be translated into an index of the number stored in the key matrix. Then, Caesar's shift with pre-defined constant value is fabricated to finalize an encryption algorithm. In decode process, Caesar's shift is applied first, and the generated key matrix is used with 2D magic squares to replace the index numbers in ciphertext to restore an original text.

Crystal Structure of the Pneumococcal Vancomycin-Resistance Response Regulator DNA-Binding Domain

  • Park, Sang-Sang;Lee, Sangho;Rhee, Dong-Kwon
    • Molecules and Cells
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    • v.44 no.3
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    • pp.179-185
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    • 2021
  • Vancomycin response regulator (VncR) is a pneumococcal response regulator of the VncRS two-component signal transduction system (TCS) of Streptococcus pneumoniae. VncRS regulates bacterial autolysis and vancomycin resistance. VncR contains two different functional domains, the N-terminal receiver domain and C-terminal effector domain. Here, we investigated VncR C-terminal DNA binding domain (VncRc) structure using a crystallization approach. Crystallization was performed using the micro-batch method. The crystals diffracted to a 1.964 Å resolution and belonged to space group P212121. The crystal unit-cell parameters were a = 25.71 Å, b = 52.97 Å, and c = 60.61 Å. The structure of VncRc had a helix-turn-helix motif highly similar to the response regulator PhoB of Escherichia coli. In isothermal titration calorimetry and size exclusion chromatography results, VncR formed a complex with VncS, a sensor histidine kinase of pneumococcal TCS. Determination of VncR structure will provide insight into the mechanism by how VncR binds to target genes.