• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.281-284
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• 1999

Ground truth measurement system using RC helicopter is very useful to measure BRDF. The helicopter is operated human operator but it can keep its position by GPS aided hovering system. We developed the measurement system and have done ground truth in Mongolia in the summer of 1999 and have made sure the system can measure BRDF expectedly.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.206-210
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• 2012

Ground source heat pump is a central heating and cooling system that pumps heat to or from the ground. Building Integrated Geothermal system used in this experiment is one of the Ground Source Heat Pump Systems which utilize energy pile. The purpose of this study is to evaluate heating performance of the system. The building is a low-energy experiment apartment in Yonsei University Songdo Campus and the subject is one of the energy reduced houses in this apartment. In the experiment, indoor temperature, outdoor temperature and the inlet and outlet temperature of ground heat exchanger and subject model, were measured. Then the heat pump's Coefficient of performance(COP) of the heat pump was calculated. As a result, the COP of heat pump is 4-5. Although the depth of the ground heat exchanger in this experiment is shallower than usual heat exchanger, the result of heating performance of this system was good as well.

• 항공우주시스템공학회지
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• 제1권4호
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• pp.13-21
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• 2007

As one of YHF digital data link technologies, VDL Mode 2 is designed to be an air-to-ground subnetwork of the Aeronautical Telecommunication Network (ATN) based on the Open System Interconnection (OSI) architecture. VDL Mode 2 can be used in ATS Applications especially for CPDLC and ADS. And it is also expected to replace ACARS (Aircraft Communications Addressing and Reporting System) which has broadly been used in AOC for over 20 years. This paper presents the design result of VDL Mode 2 system under AOA (ACARS Over AVLC) environment for the implementation of bit-oriented ATS applications. The system is composed of airborne and ground subsystem. Airborne subsystem consists of VDR, CMU and an aircraft test equipment with CPDLC/ADS client applications for operational test and ground system consists of Ground Station which includes ground VDR and ground communication controller, simple DSP (Datalink Service Processor) and a ground test equipment with CPDLC/ADS server applications.

• 한국지열·수열에너지학회논문집
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• 제14권4호
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• pp.43-52
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• 2018

This paper presents the cooling performance analysis results of a ground-source heat pump (GSHP) system using hybrid ground heat exchanger (HGHE). In this paper, the HGHE refers to the ground heat exchanger (GHE) using both a vertical GHE and a surface water heat exchanger (SWHE). In order to evaluate the system performance, we installed monitoring sensors for measuring temperatures and power consumption, and then measured operation data with 4 different load burdened ratios of the hybrid GHE, Mode 1~Mode 4. The measurement results show that the system with HGHE mainly operates in Mode 1 and Mode 2 over the entire measurement period. The average cooling coefficient of performance (COP) for heat pump unit was 5.18, while the system was 2.79. In steady state, the heat pump COP was slightly decreased with an increase of entering source temperature. In addition, the parallel use of SWHE and VGHE was beneficial to the system performance; however, further research are needed to optimize the design data for various load ratios of the HGHE.

• 대한건축학회논문집:구조계
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• 제34권3호
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• pp.87-93
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• 2018

Ground source heat pump(GSHP) system is one of the high efficiency heat source systems which utilizes the constant geothermal energy of a underground water or soil. However, the design of conventional GSHP system in the domestic market is dependent on the experience of the designer and the installer, and it causes increase of initial installation cost or degradation of system performance. Therefore, it is necessary to develop a guideline and the optimal design method to maintain stable performance of the system and reduce installation cost. In this study, in order to optimize the GSHP system, design factors according to ground heat exchanger(GHX) type have been examine by simulation tool. Furthermore, the design factors and the correlation of a single U-tube and a double U-tube were analyzed quantitatively through sensitivity analysis. Results indicated that, the length of the ground heat exchanger was greatly influenced by grout thermal conductivity for single U-tube and pipe spacing for double U-tube.

• 한국지열·수열에너지학회논문집
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• 제17권4호
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• pp.59-67
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• 2021

In this study, the performance of the single heat source system and the hybrid system was comparatively analyzed. Case 1 is a ground heat source system, and Case 2 is a water heat source system. Case 3, a hybrid system, reduced the capacity of the ground heat source and applied a water heat source as an auxiliary heat source, and Case 4 was composed of a system that applied a water heat source as an auxiliary heat source to the ground heat source system. As a result of the simulation, in case 3, energy consumption was reduced by up to 2.67% compared to ground sources for cooling. In Case 4, COP was improved by up to 10.02% compared to ground sources during cooling, and EST was calculated to be 2.42℃ lower. During heating, 0.83% was improved compared to the water heat source. At this time, the EST was calculated to be 2.25℃ higher than the water heat source.

• 대한지질공학회:학술대회논문집
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• 대한지질공학회 2002년도 정기총회 및 학술발표회
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• pp.235-248
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• 2002

지하수개발 기술의 발전과 생활여건 개선으로 지하수의 사용이 증가되면서 지하수에 대한 관리상 어려움과 여러 문제점들이 발생하고 있다. 지하수관리체계의 부실, 관리 인원의 부족, 무분별한 개발 등으로 지하수 오염 및 수량부족 현상이 가중되고 있고, 또한 지하수관 정의 관리가 어려워 지역적인 과잉개발이나 폐공이 방치되는 현상이 나타나고 있다. 본 논문은 GIS를 이용한 지하수관리의 시스템구축 모델을 제시하고, 지하수관리시스템에 필요한 분석기능 및 지하수관리 방법을 구현하여 효율적인 지하수관리가 이루어질 수 있도록 하는데 목적이 있다. 지하수개발의 위치정보를 기록하고 개발자료와 현장조사자료 등의 여러 자료를 D/B화 하였다. 또한 위성영상을 이용한 선구조 분석 자료와 수리시험 자료, 수질조사 자료 등을 활용하여 지역별 특성 값을 주제도로 작성하였고, 이러한 자료들을 활용하여 지하수 모델링 기초자료를 자동 생성할 수 있도록 하였다. 신규 지하수개발 위치에 대하여 주변의 지하수개발현황 및 오염원 현황, 선구조의 발달, 오염취약성도(DRASTIC), 수질조사 등의 자료를 손쉽게 파악할 수 있는 장점이 있다. 지하수관리시스템은 이러한 기능들을 이용하여 지하수개발 적지선정이 가능하다.

• 한국지열·수열에너지학회논문집
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• 제9권4호
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• pp.9-14
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• 2013

A ground loop heat exchanger for the ground source heat pump system is the important equipment determining the thermal performance and initial cost of the system. The length and performance of the underground heat exchanger is dependent on ground thermal conductivity, operation hours, ground loop diameter, grout, ground loop arrangement, pipe placement and design temperature. In this study we find out heat exchanger length with various design factor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.566-570
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• 2001

Generally, grounding systems are responsible for the safe operation of a power system. Their performance guarantees equipment protection and personnel safety under condition of the limited ground potential rise and touch voltages as well as step voltages under ground fault conditions. Therefore, it is necessary to measure the ground resistance frequently for checking the performance of grounding system, In this paper the ground resistance measuring system using digital signal processor and high-performance L-C resonant band pass filter is presented. The signal current magnitude for measuring ground resistance in this system is $10^{-1}[A]\;to\;5\times10^{-2}[A]$ and the current frequency is 30[Hz].

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.493-500
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• 2001

The construction of bored tunnels in soft ground inevitably causes ground movements. In the urban environment these may be of particular significance, because of their influence on buildings, other tunnels and services. The prediction of ground movements and the assessment of the potential effects on the structures is therefore an essential aspect of planning, design and construction of a tunnelling project in the urban environment. In this study, to minimize the effect of tunnelling-Induced ground movements on the adjacent structures, a system for tile settlement risk management was developed. The GIS based risk assessment system for adjacent structures developed in this study consists of several modules such as building information module, settlement evaluation module, potential risk assessment module for adjacent structures, and analysis module for monitoring data. This system focuses on controlling and managing construction processes that may lead to settlement In the surrounding buildings and can contribute to producing the optimum technical and economic design.