• 디지털산업정보학회논문지
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• 제5권2호
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• pp.141-156
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• 2009

As the TCP is the protocol designed for the wired network that packet loss probability is very low, because TCP transmitter takes it for granted that the packet loss by the wireless network characteristics is occurred by the network congestion and lowers the transmitter's transmission rate, the performance is degraded. The Snoop Protocol was designed for the wired network by putting the Snoop agent module on the BS(Base Station) that connect the wire network to the wireless network to complement the TCP problem. The Snoop agent cash the packets being transferred to the wireless terminal and recover the loss by resending locally for the error occurred in the wireless link. The Snoop agent blocks the unnecessary congestion control by preventing the dupack (duplicate acknowledgement)for the retransmitted packet from sending to the sender and hiding the loss in the wireless link from the sender. We evaluated the performance in the wired/wireless network and in various TCP versions using the TCP designed for the wired network and the Snoop designed for the wireless network and evaluated the performance of the wired/wireless hybrid network in the wireless link environment that the continuous packet loss occur.

• KIEAE Journal
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• 제13권2호
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• pp.39-46
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• 2013

Recently, the field of construction is putting a variety of effort into reducing CO2, since global warming is being accelerated due to climate changes and the increase of greenhouse gas. For reduction of CO2 in the field of construction, it is required to make plans to cut down heating energy of buildings and especially, it is urgently needed to cut down energy of residential buildings in rural area where occupies the majority of consumption of petroleum-based energy sources. Therefore, this research compared and analyzed the actual energy consumption, by evaluating energy performance of a detached house applying passive house design components for reduction of energy. As the result, energy consumption showed remarkable differences, according to the operation of a heat recovery ventilation unit which is one of passive house design components, and building energy consumption displayed remarkable differences, too, depending on the difference of airtightness performance during building energy simulation conducted in process of design. Based on these results, the importance of airtightness performance of passive house was verified. The result of the actual measurement of energy consumption demonstrated that LNG was most economical amongst several heat resources yielded, on the basis of LPG source energy consumption measured within a certain period of time, and it was followed by kerosene. LPG was analyzed to have a low economic efficiency, when used for heating.

• 한국학교수학회논문집
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• 제3권1호
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• pp.149-163
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• 2000

The Ministry of Education have had us practice the performance test as a substitute proposal, however, all the more for the idealistic purport, our education front does not have such a sufficient condition as to practice the performance test for many classes and miscellaneous duties and over-populated class, and that practice has been enforced so abruptly without any drastic preparation and has caused much confusion from the beginning of that enforcement. Thus, these problematic concerns are remained as the tasks of the teachers to be solved by themselves in the front of education, and herein I came to do this research. The followings are the conclusions that I got as the results of the research (1) Performance test style should be applied in consideration of the students' achievement level and the gap of the teachers' recognition; descriptive test, portfolio assignment and formative test styles were proper for the students lacking basic study ability. (2) Descriptive test should have its beginning with the question items to which students can write the problem solving procedure logically rather than those to evaluate the creation ability and thinking ability: and putting down specifically the assessment standard could prevent students' confusion and scheme the impartiality of the assessment. (3) Portfolio assignment evaluation should be given with as interesting and suitable amounts as possible so that the students can do by themselves. (4) Utilizing the performance test table enabled easy management of documentary evidence. And it is needless to say that the success of the performance test should have preceding conditions like the teachers' understanding and their positive participation. Therefore, I'd like to give suggestions herein like the followings; (1) The performance test should not always be made into grades, and there is a need to develop the test gradually in the condition that the education surroundings permit by checking time, frequency, ratio and contents of the test while practicing the multiple choice writing test. (2) As long as the performance test has the aims of improving the studying and learning activities, any performance test only for the sake of making numerals with the thought that assessment is the disposal of the grades should be avoided, and the change of the lecturing styles and development of various assessing types and studying materials should be endeavored to confirm with the aims.

• 한국건설관리학회논문집
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• 제10권2호
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• pp.14-25
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• 2009

많은 기업들은 그들의 기업 목적을 달성하기 위해 사업의 성과를 관리한다. 그 중 BSC의 개념을 적용한 성과측정 방법이 널리 사용되고 있고, 현재 건설 산업에서는 BSC 기반의 프로젝트 성과관리가 균형적인 성과 평가를 위해 도입되고 있다. 많은 건설 기업들은 BSC를 적용하는 단계에 있고 성과를 측정하는 데 많은 부분 노력을 기울이고 있다. 그러나 측정된 성과 결과에 대한 분석과 활용이 미비하다. 따라서 본 연구에서는 건설기업에서 성과를 적극적으로 활용할 수 있도록 성과관리 모델을 제시하고 시스템 구축을 최종목표로 한다. 이를 위해 분석 및 활용을 고려한 성과관리 프로세스를 정의하고 이에 따라 프로세스의 각 단계에 따른 방법을 제시한다. 다음으로 성과관리의 전반적인 흐름을 이해하고 시스템 구축을 가능하게 하는 모델을 수립하고 그 기대효과를 검토한다. 결론적으로 이 연구는 건설 산업의 성과관리 시스템과 건설 애플리케이션의 가치를 높이는 기회를 제공한다.

• 한국환경보건학회지
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• 제34권3호
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• pp.233-239
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• 2008

In order to improve reactor performance of existing sewage treatment plants, the feasibility of enhancing reactor performance by bioaugmentation using EM as bioaugmentation agent and the effects of anoxic: oxic time ratio on reactor performance were investigated. Continuous and intermittent aeration modes were compared under the 6 hr of HRT. Three different types of intermittent aeration modes, that is, 15 min, of anoxic:45 min of oxic, 30 min of anoxic: 30 min of oxic, and 45 min of anoxic: 15 min oxic respectively were chosen as test modes to study the effects of anoxic : oxic time ratios on reactor performance. The optimum anoxic: oxic time ratio was 30 min:30 min when considering simultaneous removal of organic, nitrogen and phosphorus. When applying EM into a continuously aerated reactor under the varying dosing rates of 50-200 ppm, reactor performance in terms of organic and nitrogen removal efficiencies was not improved at all. Nitrogen removal efficiency was increase when the EM dosing rate was increased. However the degree of improvement was slight when the EM was injected above 100 ppm. However optimum phosphorus removal was found at the EM dosing of 200 ppm. Thus it was found that optimum injection concentration of EM is 200 ppm. It is apparent that putting EM into a sewage treatment plant significantly affects the T-N removal efficiency of the reactor by enhancing denitrification efficiency especially in operational conditions of relatively long anoxic periods. To achieve reciprocal condition in a reactor with intermittent aeration it is necessary to enhance the reactor performance by EM injection. In the case of modifying existing continuously aerated reactors into intermittent aerated reactors, it is obvious that operating costs of aeration would be reduced by reducing aeration time when compared with existing conventional sewage treatment plants.

• 지식경영연구
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• 제18권2호
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• pp.1-22
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• 2017

Knowledge creation has become one of core assets for companies' survival and success, companies are putting their effort to find the way to stimulate sharing knowledge among their workers. In this vein, the purpose of this study was to examine the effect of supervisor support and co-worker support on knowledge sharing and the mediating effects of work engagement. 328 employees from varity of organizations located in Korea particiapted for questionnaire survey. Structural equation modeling was used to analyze the data. The result has shown that the static correlation exists between supervisor support, co-worker support and work engagement. Co-worker support had positive influences on knowledge sharing intention. However, supervisor support did not have any influence on knowledge sharing intention. There was a mediate effect of work engagement between both of supervisor and co-worker support and knowledge sharing intention. The study implies that co-worker support is important in order to improve organizational learning and work engagement as a strategy to enhance organizational performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.459-461
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• 1994

This paper proposed a new converter topology improving the split source type converter. In this converter. two switches and six diodes add to the split source type converter. The proposed converter has a performance minimized a negative torqe, putting a phase current off by double impressed voltage 2Vdc. Hence, a new converter results in increase of the average output power and improves converter efficiency in heavy load and high speed. Theoretical prediction is verified by experimental results got with a new proposed converter and 8/6 poles SRM.

• 지식경영연구
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• 제15권4호
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• pp.57-78
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• 2014

Since team performance has become one of the core factors for companies' success, companies are putting every effort to raise team productivity. In this vein, the purpose of this study was to examine the influence of team learning behavior upon team dynamic capabilities, team effectiveness, and to verify the mediating effect of team dynamic capabilities in corporations. 312 employees were randomly selected to participate in an questionnaire survey. The result has shown that the static correlation exists between team learning behavior, team dynamic capabilities, and team effectiveness. Team dynamic capabilities mediated the relationship between team learning behavior and team effectiveness. Based on the findings, the study implies that learning behaviors among team members should be supported in order to improve its outcome, and HR representatives must help to develop dynamic capabilities.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.956-959
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• 2007

The extension of a road system result from construction of the builling near the noise source as the roads, railroads. Many people who have a living space near the road are damaged by the noise generated the road system. Therefore, the damage will be reduced by the appropriate measure like putting some distance between receiver and source. The windows are weak among the building materials. But mainly we uses the windows as building exterior materials. So the sound insulation of the balcony windows was measured and compared.

• The Journal of the Acoustical Society of Korea
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• 제25권3E호
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• pp.131-136
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• 2006

The PML developed for the radio wave propagation is a powerful numerical domain truncation technique. We perform an analytic study on the reflection from the PML inserted in the ocean bottom. In the ocean bottom, we show the PML to have the improved performance but simultaneously the degeneration below the critical angle of the fast ocean bottom. The degeneration of the PML can be simply relaxed by stretching the thickness of the PML or putting the attenuation coefficient to the ocean bottom. As a better solution, we propose the improved truncation technique based on the PML and the non-local boundary condition. Finally, we apply the PML to the acoustic wave propagation using split-step Pade PE solver. For the problems of the ocean waveguide, the numerical efficiency of the PML is examined and the usefulness of the PML is confirmed.