• 설비공학논문집
• /
• 제24권3호
• /
• pp.230-239
• /
• 2012

Ground-coupled heat pump (GCHP) systems utilize the immense renewable storage capacity of the ground as a heat source or sink to provide space heating, cooling, and domestic hot water. The main objective of the present study is to investigate the cooling and heating performance of a small scale GCHP system with horizontal ground heat exchanger (HGHE). In order to evaluate the performance, a water-to-air ground-source heat pump unit connected to a test room with a net floor area of 18.4 m2 and a volume of 64.4 m3 in the Korea Institute of Construction Technology ($37^{\circ}39'N$, $126^{\circ}48'E$) was designed and constructed. This GCHP system mainly consisted of slinky-type HGHE with a total length of 400 m, indoor heat pump, and measuring devices. The peak cooling and heating loads of the test room were 5.07 kW and 4.12 kW, respectively. The experimental results were obtained from March 15, 2011 to August 31, 2011 and the performance coefficients of the system were determined from the measured data. The overall seasonal performance factor (SPF) for cooling was 3.31 while the system delivered heating at a daily average performance coefficients of 2.82.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
• /
• pp.1113-1116
• /
• 2008

실리카퓸, 플라이애쉬, 고로슬래등 미분말 혼화재가 포함된 고성능 콘크리트(High Performance Concrete) 교량 바닥판 보호공법은 1980년 초부터 북미를 중심으로 사용되어 왔다. 본 보고서에서는 교량 바닥판 보호를 위한 고성능 콘크리트 적용사례와 고성능 콘크리트를 이용한 두 가지 공법(고성능 콘크리트 교면포장공법, 노출 바닥판 공법)에 대해 소개한다. 위 두 공법은 이미 북미에서 많은 실적을 보유하고 있으며 특히, 실리카퓸과 PVA섬유가 포함된 고성능 콘크리트 교면포장공법은 국내에서도 성공적으로 적용되고 있다. 따라서 본고에서는 기존 아스팔트 재료를 대체할 수 있고, 최근 국내에서도 그 적용성에 대한 관심과 실 시공이 이루어지고 있는 고성능 콘크리트를 이용한 교면포장 (Overlay) 공법 및 노출 바닥판(Full depth) 공법에 대해 소개하고자 한다.

• 대한인간공학회지
• /
• 제33권1호
• /
• pp.27-37
• /
• 2014

Objective: This study aims to improve human performance by analyzing the operators' tasks and providing input data on the composition of future SMART operators. Background: SMART is a nuclear reactor for export which needs operators who can satisfy both safety and economic feasibility. Therefore, this study is fundamental research on the composition of operators and this research analyzed SMART tasks in terms of human safety performance. Method: After analyzing 10 SMART EOG in hierarchical task analysis, this study classified task performance types according to task requirements of NUREG-0711 (Rev.3). Results: This study found the task frequency of SMART EOG and 12 operating task types. Conclusion: This study expects that human performance can be improved by analyzing the personal errors, which have the highest task frequency among 12 operating task types. Application: The results of this study can be applied as base data when licensing needs to be acquired.

• 한국추진공학회지
• /
• 제19권3호
• /
• pp.89-95
• /
• 2015

7톤급 로켓엔진용 산화제펌프와 연료펌프에 대하여 물을 매질로 하는 성능시험을 수행하였다. 펌프는 전기모터로 구동되었고 설계 및 탈설계 유량비 조건에서 펌프의 수력성능과 흡입성능이 측정되었다. 양정-유량 곡선, 효율-유량 곡선, 양정-캐비테이션수 곡선을 얻었다. 개발된 펌프는 펌프 양정과 효율의 수력성능에 관한 설계요구조건을 만족시킬 수 있음을 확인하였다. 또한 흡입성능에 관한 설계요구조건을 만족시킨다.

• International Journal of Internet, Broadcasting and Communication
• /
• 제13권1호
• /
• pp.1-10
• /
• 2021

The type approval system for railway vehicle has been in effect since 2016 in order to establish a regular safety management system to secure railway safety and enhance the technological competitiveness of the railway industry, abolished the conventional performance test system through the reform of the Railroad Safety Act in 2012. Until now, there has been appreciated it has been making significant contributions to railway safety and industry of operation and manufacturing companies, taking their place in accordance with the implementation of the system. But there has been no case of quantitative analysis on the effectiveness of the actual system. In this study, in order to examine the full-scale performance of the approval system and quantitatively analyze effectiveness, we identified and defined the relationships with the major elements of the type approval system based on system thinking principle and determined the calculated outcomes to relevant stakeholders. A method of establishing a type approval performance management system that can be grasped, utilized, and adjusted from a point of various stakeholders' views was proposed. This is expected to be more helpful in the implementation of the system, such as improving and applying quantitative effects to analysis by closely reviewing the effects and influencing factors of the type approval system based on the data accumulated through continuous performance management and reflecting to system improvement.

• 한국항공운항학회지
• /
• 제30권4호
• /
• pp.9-22
• /
• 2022

With the continuous increase in demand for air transport services and the growth of the air transport industry, the International Civil Aviation Organization (ICAO) and its member states are facing social demands to expand the capacity of the air transport system and improve the efficiency of its operation. ICAO developed the concept of Performance Based Navigation (PBN) for the purpose of solving problems related to the function and performance of the navigation system. Member countries established an implementation plan in accordance with the resolutionof the ICAO General Assembly, and South Korea established a Performance-Based Navigation implementation plan in December 2009. This paper evaluates the progress made so far based on Korea's Performance-Based Navigation implementation plan and proposes a development direction for Performance-Based Navigation based on changes in the international environment.

• 한국정보전자통신기술학회논문지
• /
• 제16권2호
• /
• pp.61-68
• /
• 2023

수중통신에서 다중 밴드 기법은 채널 부호화된 동일한 데이터를 여러 주파수 밴드로 나누어 전송하는 기법인데, 이는 수중에서 다중 경로, 도플러 확산 등으로 인한 특정 주파수의 선택적 페이딩 현상을 극복하면서 성능을 향상시키는 기법이다. 이러한 다중 밴드 통신의 단점은 성능이 열악한 특정한 밴드가 전체 성능에 영향을 미친다. 따라서 본 논문에서는 다중 밴드 통신에서 각 밴드의 성능을 예측하여 가장 신뢰성이 높은 밴드를 선택함으로써 성능을 향상시키는데, 본 논문에서는 세 가지 성능을 예측하는 기법을 제시하였으며, 실험을 통하여 프리엠블 오류율을 이용하는 방법이 가장 효율적인 방법임을 확인하였다.

• 국제학술발표논문집
• /
• The 9th International Conference on Construction Engineering and Project Management
• /
• pp.1252-1252
• /
• 2022

Temporary work that utilizes temporary equipment (e.g., system scaffold and system pipe support) in construction work is one of the most vulnerable work from a safety perspective in South Korea. Typically, temporary equipment is reused at construction sites. The Korea Occupational Safety and Health Agency announced guidelines regarding the performance standards for reusable temporary equipment to prevent the accidental collapse of temporary facilities. Nevertheless, temporary facilities' collapse still occurs, which could be attributed to a degradation in the performance due to the reuse of temporary equipment. Therefore, this study investigated the performance of simple temporary structures assembled with new and reused equipment. To this end, an experimental module was designed based on previous research cases, and two experimental models were constructed, in which one was assembled using new equipment (Model A), and the other was built using reused equipment (Model B). To determine the performance of each model, a load test was conducted to measure the maximum load that each model could withstand. The experimental results revealed that the maximum load of Model B was 15% lower than that of Model A. This indicates that there is a meaningful performance difference between those two models. Based on this result, the authors decided to perform additional tests with more realistic models than previous ones. The new experimental module was designed to ensure compliance with the Korean design guidelines. In this presentation, the authors show details of the first tests and their results and plan for the additional test.

• 무역학회지
• /
• 제45권5호
• /
• pp.261-277
• /
• 2020

The purpose of this study is to analyze whether SMEs' technological capabilities and international marketing capabilities affect the export performance of the SMEs and to empirically test the moderating effect of the CEO's risk propensity on such a relationship. We obtained data from 190 SMEs located in Gwangju and Jeonnam Province in Korea through survey and performed a regression analysis for hypothesis testing based on these data. As a result of the analysis, it was found that SMEs' technological capabilities and international marketing capabilities had a significantly positive (+) effect on export performance, respectively. Also, the CEO's risk propensity was found to reinforce the relationship between technical competence and export performance, and the relationship between marketing capabilities and export performance was also found to be strengthened in the positive (+) direction. These results suggest that it is necessary for SMEs to continuously develop technological capabilities and international marketing capabilities to achieve successful export performance in overseas markets. Also, the CEO's propensity to promote these relationships may be important.

• 무역학회지
• /
• 제45권5호
• /
• pp.23-35
• /
• 2020

The purpose of this study is to examine relationships among exhibition selection factor, performance, satisfaction and intention to revisit of participants in international exhibition. For this purpose, we set hypotheses relationship among external selection factor of exhibition (ESFE), internal selection factor of exhibition (ISFE), performance of sales (PS), performance of information gathering (PIG), performance of relationship building (PRB), performance of image building (PIB), satisfaction (SAT) and intention to revisit (IR). To verify theses hypotheses, we conducted path analysis on the data from 100 participants of 2019 Korea International Boat Show. The result of this study is as follows: Frist, ESFE positively impacts on PS, PIG, PRB, PIB. Second, ISFE positively impacts on PIG, PRB. Third, PS and PIB positively impacts on SAT. Fourth, SAT positively impacts on IR. The implication of this study is two fold. This study expands research area of international exhibition to a new industry such as marine leisure sports industry and provides useful information to firms that plan to participate in the international exhibition and to those who organize the international exhibitions.