• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.8-14
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• 2013

Hydrogen-natural gas blends(HCNG) engine is optimizing technology of performance and emission characteristics with use of hydrogen's fast flame speed and wide flammability limit. As lean-burn limit is extended, the improvement in thermal efficiency and harmful emissions can be achieved. However, the extension of lean-burn limit under a wide open throttle operation point could be realized with the increase in boosting capacity in a lean-burn engine with turbo-charging system. In the present study, the power output characteristics of HCNG engine with turbo-charger change is assessed and feasibility of the increase in boosting capacity is evaluated. The turbo-charger design with high efficiency at higher flow rate rather than higher boosting pressure makes efficient operation possible at relatively rich mixture condition.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.41-48
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• 2008

Background: Accurate assessment of the preload and the fluid responsiveness is of great importance for optimizing cardiac output, especially in those patients with coronary artery occlusive disease (CAOD). In this study, we evaluated the relationship between the parameters of preload with the changes in the stroke volume index (SVI) after fluid loading in patients who were undergoing coronary artery bypass grafting (CABG). The purpose of this study was to find the predictors of fluid responsiveness in order to assess the feasibility of using. certain parameters of preload as a guide to fluid therapy. Material and Method: We studied 96 patients who were undergoing CABG. After induction of anesthesia, the hemodynamic parameters were measured before (T1) and 10 min after volume replacement (T2) by an infusion of 6% hydroxyethyl starch 130/0.4 (10 mL/kg) over 20 min. Result: The right ventricular end-diastolic volume index (RVEDVI), as well as the central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP), failed to demonstrate significant correlation with the changes in the SVI (%). Only the right ventricular ejection fraction (RVEF) measured at T1 showed significant correlation. with the changes of the SVI by linear regression (r=0.272, p=0.017). However, when the area under the curve of receiver operating characteristics (ROC) was evaluated, none of the parameters were over 0.7. The volume-induced increase in the SVI was 10% or greater in 31 patients (responders) and under 10% in 65 patients (non-responders). None of the parameters of preload measured at T1 showed a significant difference between the responders and non-responders, except for the RVEF. Conclusion: The conventional parameters measured with a volumetric pulmonary artery catheter failed to predict the response of SVI following fluid administration in patients suffering with CAOD.

• 전기의세계
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• v.36 no.8
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• pp.568-571
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• 1987

레이저는 금세기의 최대이고 최후의 발명이라고 말한다. 1960년대에 처음 레이저의 발진이 실현된후 벌써 4분의 1세기가 지났으며 오랫동안 과학의 위대한 결과로 칭송만되었던 레이저는 최근 서서히 공업의 과실로서 산업계에 등장하고 있다. 양자효과라는 것은 대체로 마이크로의 세계에 나타나지 않지만, 레이저 현상은 마이크로의 세계에 실현된다. 이때 원자 및 분자의 기능은 그대로 집약되어 우리의 오감에 전달되는 것이다. 가간섭적인 레이저광은 전파로 할 수 있는 기술의 거의 전부를 빛의 영역으로 수용할 수 있다. 물질의 가공, 동위체분리, 모든 계측에 사용되며 최근에는 핵융합의 개발에 중요한 역할을 담당하고 있다. 레이저에는 무한의 가능성이 내장되어 있다.

• Journal of the Korean Institute of Gas
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• v.20 no.4
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• pp.58-64
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• 2016

The main engine of a vehicle is used an common rail diesel engine for improving the efficiency of the whole load area. However, the generator engines is still used mechanical fuel injection valve drive cams. In addition, most of generator engines is applied a part-load operation of less than 50%. Therefore, diesel engine of vehicle set at 100% load is necessary to readjust in order to perform efficient operation because of part-load operation. In this study, the objective is to report the results of the part-load fuel consumption improvement by injection timing readjust to identify the operational characteristics of a generator engine currently operated in the facilities.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.338-339
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• 2011

본 논문에서는 SRC를 이용한 고효율 차량탑재형 충전기를 제안한다. 제안한 컨버터는 앞단의 부스트컨버터가 역률보상과 동시에 배터리의 전압 전류 제어를 수행하고 후단의 SRC를 고정듀티와 고정주파수로 동작시켜 전 부하영역에서 스위치와 다이오드의 ZCS 턴온 턴오프가 가능하다. 3.3kW의 시작품으로 부터 CC-CV 충전을 통한 제안한 방식의 타당성을 검증한다.

• Journal of agricultural medicine and community health
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• v.42 no.1
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• pp.24-35
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• 2017

Objectives: This study aimed to evaluate the primary care quality of a public health center in a rural area using the Korean Primary Care Assessment Tool (KPCAT). It also examined some methodological issues in applying the KPCAT and interpreting its results. Methods: Seventy-nine patients who had visited their doctor more than four times responded to the KPCAT questionnaire. Descriptive statistics and a radar chart were used in analyzing data. Sign test was used to test the KPCAT score difference by don't know option scoring methods. Results: Median and interquartile range of the public health center's KPCAT scores were forty-five and sixteen points, respectively. Only the median of the first contact domain reached the expected value of seventy-five points. The proportions of those who scored under the expected value were under fifty percent in two of four comprehensiveness items, all of three coordinating function items, two of five personalized items and all of four family/community orientation items. There were some methodological issues including, how to score don't know option and make sure response scale consistency. Conclusions: There was much room to improve the primary care quality of the rural public health center. Especially, improvement is needed in the domain of coordinating function and family/community orientation. We also hope that methodological improvement of the KPCAT contributes to more valid and reliable primary care assessment.

• Korean Security Journal
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• no.39
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• pp.295-317
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• 2014

In advanced country, private investigation system is made up of private security and in domestic, there is growing need constantly to introduce private investigation but it is not passed until now in assembly so a messenger office which is run illegally is growing because of demand by subdividing business areas. That is a proof that both the police and private security don't meet demand of public peace to the public. that's why the police has own businesses like a investigation, traffic, intelligence, crime prevention and private security's business areas are limited like a facilities security, escort security, protection of a person, machine security, special security as the Private Security Act. This study attempts to know structural difference between private security system and private investigation system in case private investigation system becomes one of the private security. on some question, respondents reply like that private security and private investigation is very different(71.2%), different(22.4%), average(6.3%), similar(0.0%), very similar(0.0%). the result seems like respondents recognize private security and private investigation as different businesses. In the result of non-quantity analysis, the differences seem like a business character, expense, business scope, public power, scale of organization, object of threat, legislation. In domestic, effort to legislate private investigation system has undergone difficulty since congressman Ha Soon Bong's motion in 1999 and today, congressman Yoon Jae Ok's All Amendments Private Security Act and congressman Song Young Geun's Private Inveswtigation Act are pending in assembly. This study's result is intended for examining difference in exploration between private security and private investigation and then there is going to propose to the policy in case private investigation system is passed in assembly by amending Private Security Act like congressman Yoon Jea Ok's All Amendment Private Security Act.

• Journal of Korean Home Economics Education Association
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• v.23 no.2
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• pp.131-148
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• 2011

The purpose of this study was to analyze the contents of housing area in Technology Home Economics textbooks of the 2007 revised curriculum which was published in 2011. The structure and the contents of housing area which are consisted of housing/living environment and use of housing space were analyzed. This study aims to examine the changes in the newly revised textbooks as well as suggesting advice for the more improved revised one in the future. For this purpose, this study employed 11 different textbooks and the results were the followings: each textbook had different quantity of pages dedicated to housing area but commonly had the wide range of terminology, plentiful amount of tables/diagrams, reading and activity materials sufficient to have students to carry out in practice. Also, the newly added contents of local area and eco-friendly life are analyzed to be well reflecting the 2007 revised curriculum. In future textbook development, it will be important that the issue of low birth rate, population ageing and green-life to be included as well as emphasizing the content of the network within the local area in order to actively prepare for the environmental issues.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1531-1536
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• 2016

In this paper, we propose a fast motion estimation algorithm which is important in performance of video encoding. Even though so many fast algorithms for motion estimation have been published due to its tremendous computational amount of for full search algorithm, efforts for reducing computations in motion estimation still remain. In the paper, we propose an algorithm that reduces unnecessary computations only, while keeping prediction quality the same as that of the full search. The proposed algorithm does not calculate block matching error for each candidate at once to find motion vectors but divides the calculation procedure into several steps and calculates partial sum of block errors. By doing that, we can estimate the minimum error point early and get the enhancement of calculation speed by reducing unnecessary computations. The proposed algorithm uses smaller computations than conventional fast search algorithms with the same prediction quality as full search.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.34-39
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• 2018

Natural gas is attracting attention as an alternative to existing fossil fuels. Natural gas has a high octane number. Therefore, knocking does not occur even if the compression ratio is increased, so that the thermal efficiency and the output can be improved. And it is relatively easy to apply the natural gas supply system to the internal combustion engine hardware system. In this study, a gasoline direct injection turbo engine was converted into a natural gas port injection type turbo engine. Therefore, the combustion and performance of the engine are measured and compared comprehensively in the region where the turbo operates.