• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.261-267
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• 2013

In this paper, the effective information transfer technique between computing device and portable device that is connected through USB interface has been studied. The proposed technique is realized by the method which portable device is perceived into optical media such as CD-ROM or CD-R/W through SCSI commands on USB interface. Through the proposed system in this study, we maximized user convenience by executing diverse works using stored data in a portable device without installing extra USB driver corresponding to portable device, when user data is transmitted between computing device and portable device. We conducted experimental tests to verify the performance of the proposed system through implementing of test system. As a result, we confirmed the technique is comparatively superior to existing method in transmitting speed and user convenience.

• Journal of the Computational Structural Engineering Institute of Korea
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• 제17권3호
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• pp.251-259
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• 2004

The prediction accuracy of prestress plays an important role in the quality of maintenance and the decision on rehabilitation of infrastructure such as prestressed concrete bridges. In this paper, the Bayesian statistical method that uses in-situ measurement data for reducing the uncertainties or updating long-term prediction of prestress is presented. For Bayesian analysis, prior probability distribution is developed to represent the uncertainties of creep and shrinkage of concrete and likelihood function is derived and used with data acquired in site. Posterior probability distribution is then obtained by combining prior distribution and likelihood function. The numerical results of this study indicate that more accurate long-term prediction of prestress forces due to creep and shrink age is possible.

• Publications of The Korean Astronomical Society
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• 제19권1호
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• pp.83-92
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• 2004

In this paper, we introduce the development of the large storage system in order to record the observed space radio signal in the Korean VLBI Network(KVN) with high-speed. The KVN is the Very Long Baseline Interferometery(VLBI) to observe the birth of star, the structure of space by constructing radio telescope with diameter 21m at the Seoul, Ulsan, Jeju from 2001 to 2007 years. To do this, Korea Astronomy Observatory joined the international consortium for developing the high-speed large storage system(Mark 5), which is developed by MIT Haystack observatory. The Mark 5 system based on hard disk has to record up to 1 Gbps the observed space radio signal. The main features of Mark 5 system are as follows; First it is able to directly record the input data to the hard disk without PC1(Peripheral Component Interconnect) internal bus, and the second, it has two hard disk banks, which are able to hot-swap ATA/IDE type very cheap up to 1 Gbps recording and playback. The third is that it follows the international VLBI standard interface hardware(VSI-H). Therefore it can be connect directly the VSI-H type system at the input/output. Finally it also supports e- VLBI(Electronic-VLBI) through the standard Gigabits Ethernet connection.

• Journal of the Korean Geotechnical Society
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• 제21권2호
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• pp.37-46
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• 2005

In the field of earthquake engineering, recent improvements in many areas, such as seismological source modeling, analysis of travel path effects, and characterization of local site effects on strong shaking, have led to significant advances in both code-based and more advanced procedures for evaluating earthquake ground motions. A missing link, however, is empirically verified design procedures fur assessing the effects of soil-structure interaction (SSI). Available Soil-Structure Interaction (SSI) analysis techniques range from simple substructure-type procedures to relatively sophisticated finite element procedures. The most common substructure approach for foundation-soil interaction is to use a frequency-dependent and complex-valued impedance function. This study uniquely evaluates impedance functions for two well-instrumented sites w significant inertial SSI effects using a system Identification technique. The system identification analysis results are then compared to predictions from a simple theoretical model to gain insight into the inertial interaction effect in the subject sites.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제10권5호
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• pp.897-904
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• 2006

The eastern coast of northeastern Brazil (NEB), a coastal land-strip up to 300 km wide and stretching out from Rio Grande do Norte $(5^{\circ}S)$ State down to the south of Bahia State $(17^{\circ}S)$, experiences different rain producing systems, such as distrubances in the south-east trade winds, frontal systems penetration, land-sea breeze circulation and local convection associated with the topography and moisture flux convergence. The annual total rainfall ranges from 600 inland to 3000 mm on the coast. Rainfall totals 5 to 12 times the focal climatic means were recorded in various regions of Alagoas state in January 2004. It was estimated that 46,000 people were homeless, with material damages exceeding US$10 million as a consequence of the ensuing floods. GOES infrared images analysis showed that the main weather system responsible for this anomalously high rainfall totals was an Upper Troposphere Cyclonic Vortex (UTCV), which formed at about a $27^{\underline{\circ}}W\;e\;12^{\underline{\circ}}S$ and remained active for the entire month of January over NEB.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제45권2호
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• pp.140-147
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• 2017

This paper describes the design and implementation of previously developed PMU (Power Monitoring Unit) for LiPB (Lithium-ion Polymer Battery) that is electric propulsion used as unmanned aerial vehicle's power source. Improved PMU provides stable voltage and current to various sensors and elctric motors necessary during flight. Voltage and current monitoring function that is measured by improved PMU more precisely be enhanced and the monitoring channel and temperature sensor is added. To verify the improved performance of the equipment, it is integrated to electric propulsion system of unmanned aerial vehicle. PMU is calibrated through the ground test. And PMU's performance is checked through the flight test.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2011년도 학술발표회
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• pp.26-30
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• 2011

최근 기후변화에 따라 강우의 패턴이 변화하고 있다. 강우일수는 줄어드는 반면, 강우강도는 증가하여, 홍수로 인한 많은 피해에 직면하고 있다. 이러한 기상이변은 홍수방어시스템을 위한 수공구조물에도 많은 영향을 미친다. 수공구조물을 설계할 때, 일반적으로 강우 기록들의 통계적 특성이 정상성을 가진다고 가정한다. 하지만 최근의 강우 자료를 분석하면, 시간에 따라 평균, 분산, 왜곡도와 같은 기본 통계량이 변화하는 것을 알 수 있다. 따라서, 수공구조물의 설계를 위한 확률 강우량은 이러한 기후변화에 따른 자료의 특성을 반영할 필요가 있다. 본 연구의 목적은 강우 자료의 비정상성의 특성을 이용하여 확률강우량을 산정하는 것이다. 최근 비정상성 강우빈도해석에 대한 연구가 활발히 진행되고 있는데, 이들 연구는 대부분 목표연도까지 경향성의 기울기가 증가, 또는 일정하다고 가정한다. 하지만, 현재는 경향성이 있지만, 목표연도에는 경향성이 없을 경우도 있고, 또는 경향성이 있어도 그 기울기가 적어지는 경향을 보일 수도 있다. 본 연구에서는 현시점과 목표연도의 시점에 대한 경향성 기울기의 변화를 고려하여 비정상성 강우빈도해석을 수행하였다. 대상지점 선정은 통계적 경향성 검정, Mann-Kendall test를 이용하여 1994년(현재시점)에 경향성이 있다고 판단되는 관측지점을 대상지점으로 선정하였다. 분석 방법은 24시간 임계지속시간의 연최대강우자료를 구축하였다. 자료를 현시점까지 선형회귀식을 이용하여 잔차 계열을 산정하고, Gumbel 분포를 이용하여 확률 잔차를 산정하였다. 확률강우량을 추정하기 위해 추세요소를 산정하였다. 기울기의 증가 혹은 감소 경향을 회귀모형을 이용하여 추세요소를 산정하였고, 잔차의 확률빈도와 추세요소의 합으로 비정상상 확률강우량을 산정하였다.

• Korean Journal of Construction Engineering and Management
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• 제12권4호
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• pp.106-116
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• 2011

It is very important to collect and manage labor information in the construction industry that is labor-intensive. Although research and cases that utilize RFID are increasing for more effective labor management, labor management is limited to the checking-in and -out information management at the entrance of a construction site due to high expense of an RFID reader. Labor and safety information is still managed based on the redundant process that is hand-written in a book and re-input of information by using a personnel-computer. Therefore, the objective of this paper is to develop more effective and efficient process for labor information record and management. This paper presents a prototype application that supports integrated labor information management by incorporating QR-code into RFID-based labor management system and verifies the application through a pilot test and comparison with the existing labor management syste.

• Journal of KIISE:Databases
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• 제29권6호
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• pp.429-440
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• 2002

Temporal databases manage time-evolving data. They provide built-in supports for efficient recording and querying of temporal data. The temporal aggregate in temporal databases is an extension of the conventional aggregate to include time concept on the domain and range of aggregation. This paper focuses on multidimensional temporal aggregation. In a multidimensional temporal aggregate, we use one or more general attributes as well as a time attribute on the range of aggregation, thus it is a useful operation for historical data warehouse, Call Data Records(CDR), etc. In this paper, we propose a structure for multidimensional temporal aggregation, called PTA-tree, and an aggregate processing method based on the PTA-tree. Through analyses and performance experiments, we also compare the PTA-tree with the simple extension of SB-tree that was proposed for temporal aggregation.

• Journal of KIISE:Computing Practices and Letters
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• 제16권6호
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• pp.727-731
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• 2010

Recently, mobile life-log data are collected by mobile devices and used to recode one's life. In order to help a user search data, a mobile life-log semantic network is introduced for storing logs and retrieving associative information. However, associative search systems on common semantic networks in previous studies provide for a user with only found data as text to users. This paper proposes an associative search system for mobile life-log semantic network that supports selection and keyword associative search of which a process and result are a visualized graph representing associative data and their relationships when a user inputs a keyword for search. In addition, by using semantic abstraction, the system improves user's understanding of search result and simplifies the resulting graph. The system's usability was tested by an experiment comparing the system and a text-based search system.