• 인터넷정보학회논문지
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• 제22권5호
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• pp.57-67
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• 2021

Modern cloud computing is rapidly changing from traditional hypervisor-based virtual machines to container-based cloud-native environments. Due to limitations in I/O performance required for both virtual machines and containers, the use of high-speed storage (SSD, NVMe, etc.) is increasing, and in-memory computing using main memory is also emerging. Running a virtual environment on main memory gives better performance compared to other storage arrays. However, RAM used as main memory is expensive and due to its volatile characteristics, data is lost when the system goes down. Therefore, additional work is required to run the virtual environment in main memory. In this paper, we propose a hybrid in-memory storage that combines a block storage such as a high-speed SSD with main memory to safely operate virtual machines and containers on main memory. In addition, the proposed storage showed 6 times faster write speed and 42 times faster read operation compared to regular disks for virtual machines, and showed the average 12% improvement of container's performance tests.

• 한국통신학회논문지
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• 제40권4호
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• pp.750-759
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• 2015

국방 시스템 분석에서 순 방향 시뮬레이션은 주로 전장 환경에 주어진 국방 시스템의 공학 제원이나 운용 전술을 바탕으로 이에 대응하는 체계 효과도를 분석하는 과정에 활용된다. 이러한 순 방향 시뮬레이션 과정은 다양한 교전 시나리오에 대한 전투 결과를 분석하기에는 용이하나, 목표 효과도를 달성하기 위한 국방 시스템의 요구 성능을 역으로 도출할 때는 비효율적이다. 본 논문은 국방 시스템의 요구 성능 분석을 위해 역 방향 시뮬레이션 소프트웨어 아키텍처를 제안한다. 제안하는 아키텍처는 기능적으로 구분된 하위 모듈들을 바탕으로 시스템 모델을 그대로 활용하되 역 모델 설계 유무에 따라 적합한 역 방향 시뮬레이션 방안을 선택할 수 있게 하였다. 사례 연구로 수상함의 대공/대잠전 시나리오에 제안한 소프트웨어 아키텍처를 적용하였는데, 국방 시스템의 요구 성능 분석을 하는데 있어 순 방향 시뮬레이션과 비교하여 동일한 수준의 요구 성능 분석을 보다 신속히 수행할 수 있음을 보였다. 마지막으로 본 논문의 연구 결과는 국방 시스템의 운용 전술 개발 뿐 아니라 다양한 시스템의 문제해결에 적절한 해결 방안을 제시할 것으로 기대한다.

• 설비공학논문집
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• 제14권3호
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• pp.191-198
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• 2002

Cooling tower design procedure was set up using conventional Merkel theory, The design data could be different depending on the characteristic curve that the engineer chose. It reveals that the consistent and reasonable criteria are required based on the exact information of the cooling tower Performance. In this study, an off-design performance analysis program for a counterflow-type cooling tower was developed and verified by comparing with experimental data. Also, the off-design performance with various operating conditions was analyzed.

• 한국화재소방학회논문지
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• 제17권2호
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• pp.10-16
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• 2003

본 연구의 목적은 성능위주의 화재안전설계법에 따른 구획실 용도별 요구내화시간산정을 실시함으로써 현행 내화성능기준의 문제점도출 및 개선방향을 제시하는 것이다. 내화성능기준에 대한 검토를 위해 본 연구에서는 현재 국내의 시방규정에 의해 결정된 요구내화시간과 등가시간공식에 의해 산정된 화재노출상응시간과 비교하였고, 화재노출상응시간을 산정하기 위해 화재하중밀도, 환기계수, 구조재료의 열적특성 그리고 구획실 형상치수 등을 조사하였다.

• 한국군사과학기술학회지
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• 제11권3호
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• pp.67-75
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• 2008

In this paper, we analyze the performance of Follower Noise Jamming(FNJ) considering three practical tracking parameters such as tracking bandwidth, tracking time and tracking success probability. The performance of FNJ is compared with that of Partial-Band Noise Jamming(PBNJ) in terms of Symbol Error Rate(SER) at the communication receiver under the assumed typical operation model. It is observed that the performance of FNJ is non-linearly dependent on the tracking bandwidth, the tracking time and the tracking success probability. As we can easily expect, it is also observed that the performance of FNJ is better than that of the PBNJ. Finally, it is shown that, for a fixed tracking bandwidth, the combinations of the required tracking time and the tracking success probability which satisfy a certain required SER.

• 수산해양교육연구
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• 제20권3호
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• pp.358-368
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• 2008

The purpose of this study is to gather background data of teacher's performance of the fisheries and shipping industries high schools. This data will provide direction for advancing teacher's performance of the fisheries and shipping business high school,s by investigating and analyzing variables related to teacher's performance. This study focused on the opinions of thirty teachers within the fisheries and shipping business high schools. The conclusions of the study were as follows: First, teachers continually seek goal achievement, rewarding jobs, and a feeling of self-worth. However, it was found that male teachers have stronger task performing ability and form stronger relationships with their partners than female teachers. Second, it was shown that teachers have a much higher percentage of ability to teach. Particularly, male teachers are generally higher than female teacher. Third, it was shown that teachers have a much higher percentage of ability to teach, but it is required that they both get equal participation opportunity as there is a little difference between male teachers and female teachers. Fourth, it was found teachers exhibited a lower percentage rate of ability to manage activities, and required further development of programs for expansion of professionalism of this field.

• 한국정밀공학회지
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• 제27권2호
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• pp.78-85
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• 2010

The remanufacturing system is a series of industrial process in which worn-out products are restored to like-new condition. The remanufacturing system is differ from the repair system not only process characteristics but also product characteristics. So, it is required to design another model for the remanufacturing system which is distinct from the repair system and also performance index is required for the remanufacturing system. Therefore, in this paper we suggest the availability model for remanufacturing system by using Markov Process. This model represents each of the states of the remanufacturing system. Also performance indexes of remanufacturing system are introduced. Performance indexes are consisting of part reuse frequency and time, part disposal frequency and time. As a result, we can have a choice and control the proper part and offer useful information during the remanufacturing by using these availability model and performance indexes.

• 한국항공운항학회지
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• 제30권1호
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• pp.38-43
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• 2022

As the use of unmanned aerial vehicles increases, in order to expand the operability of the unmanned aerial vehicle, it is essential to develop an unmanned aerial vehicle traffic management system, and to establish the system, it is necessary to analyze the integrated navigation performance of the unmanned aerial vehicle to be operated. Integrated navigation performance is affected by various factors such as the type of unmanned aerial vehicle, flight environment, and guidance law algorithm. In addition, since a large amount of flight data is required to obtain high-reliability analysis results, efficient and consistent flight scenarios are required. In this paper, a flight scenario that satisfies the requirements for integrated navigation performance analysis of rotary and fixed-wing unmanned aerial vehicles was designed and verified through flight experiments.

• 한국건축친환경설비학회 논문집
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• 제12권6호
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• pp.591-605
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• 2018

The information on the planar figure of the building envelope is commonly required in various criteria related to the energy performance of the building. However, since the method of creating varies depending on each criterion, the information displayed in the planar figure of the building envelope differs considerably according to the person making the figure. In this regard, this study sought to derive the commonly required information for the unification of the information included in the planar figure of the building envelope, and thus examine the standardization of the planar figure of the building envelope based on BIM. Towards this end, 1) the required information about the planar figure of the building envelope was derived through the literature review and case analysis results submitted to the energy performance evaluation agencies, and 2) the standardized output technology using IFC was investigated based on the required information. Therefore, it is expected that the findings of this study will help to create a general-purpose planar figure for the building envelope, and this study can serve as the preliminary research for automatically extracting the information on the planar figure of the building envelope.

• 한국안전학회지
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• 제34권2호
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• pp.40-47
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• 2019

The Half-depth precast deck is a structural system that utilizes pre-cast panels pre-built at the factory as formwork at the construction stage and as a major structural member at the same time after completion. These systems have joints between segments, and the detail and performance of the joints are factors that have a very large impact on the quality, such as the constructability and durability of the bridge decks. In this study, strength performance evaluation was performed for improved joints using connecting rebar by experimental method. Static loading tests were conducted on the test specimen with improved joint, those with existing joint and those without joint. The test results of the specimens were compared to each other, and the flexural strength required by the design was compared. The flexural strength required in the design was presented by finite element analysis. It has been shown that the flexural strength of the specimens with joints were more than twice that required by the design. But the flexural strength of the specimen with existing joint was about 84% of that without joint. The flexural strength of the specimen with improved joints was a nearly similar degree of that compared to the specimen without joint. And a comparison of the moment-deflection relationship curves of the two specimens also shows a very similar flexural behavior. It is confirmed that improved joint has sufficient flexural strength. In addition to strength, the bridge decks require serviceability, such as deflection and cracking, and in particular, fatigue resistance due to repetitive live loads is an important performance factor. Therefore, further verification studies are required.