• Nuclear Engineering and Technology
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• 제28권2호
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• pp.175-184
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• 1996

해저에 건설된 방사성폐기물 처분장 방벽에서 핵 종 전달을 평가할 수 있는 한 모델이 제시되었다. 방벽의 출구에서의 물질전달계수와 각 방벽에 대하여 정의된 방벽응답함수를 이용하여 이들 방벽으로부터의 핵종의 전달률을 구할 수 있다. 이러한 접근은 단순하고 즉각적인 계산결과가보수적인 측면에서 요구되어지는 경우 방벽들을 연속된 별개의 매질로 다루어 각각의 응답함수를 적용할 수 있기 때문에 유용하다. 단점으로는 인접한 두 방벽사이에서, 이전의 방벽으로부터의 핵종의 유출율이 연속되는 방벽으로의 유입율로 되어 핵종속은 보존되는 반면 핵종의 농도는 반드시 보존되지는 않는다는 것으로, 이는 두 방벽 매질의 경계에서 핵종전달저항이 없다고 가정할 수 있는 것으로 해결될 수 있다. 물질전달계수는 방벽의 출구 쪽 경계에서의 핵 종의 농도가 일정하다고 보아 구할 수 있고, 매질의 응답함수는 각 방벽에 대하여 핵종의 단위 펄스입력에 대해 경계에서의 농도에 대한 해를 구한 후 물질전달계수를 적용하여 얻을 수 있다. 이리하여 한 방벽매질에 대한 시간 종속적인 핵종의 총전달률은 응답함수에 이전의 방벽에 대해 계산된 핵종의 전달률을 컨볼루트하여 구할 수 있다.

• 산업경영시스템학회지
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• 제43권3호
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• pp.1-9
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• 2020

Interest rate spreads indicate the conditions of the economy and serve as an indicator of the recession. The purpose of this study is to predict Korea's interest rate spreads using US data with long-term continuity. To this end, 27 US economic data were used, and the entire data was reduced to 5 dimensions through principal component analysis to build a dataset necessary for prediction. In the prediction model of this study, three RNN models (BasicRNN, LSTM, and GRU) predict the US interest rate spread and use the predicted results in the SVR ensemble model to predict the Korean interest rate spread. The SVR ensemble model predicted Korea's interest rate spread as RMSE 0.0658, which showed more accurate predictive power than the general ensemble model predicted as RMSE 0.0905, and showed excellent performance in terms of tendency to respond to fluctuations. In addition, improved prediction performance was confirmed through period division according to policy changes. This study presented a new way to predict interest rates and yielded better results. We predict that if you use refined data that represents the global economic situation through follow-up studies, you will be able to show higher interest rate predictions and predict economic conditions in Korea as well as other countries.

• 간호행정학회지
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• 제20권5호
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• pp.535-544
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• 2014

Purpose: This study was done to develop a schematized alarm-managing manual for continuous renal replacement therapy (CRRT) and to investigate its effects in maintaining continuity in the patients' treatment and promptly resolving alarms when CRRT is being carried out. Methods: Sixtynurses from two medical intensive care units (ICUs) (one experimental and one control) at one hospital were asked to answer a questionnaire including their CRRT nursing competency and satisfaction with the manual. Data on alarm resolution rate were collected by analyzing existing data, such as the details of each alarm and the number of resolutions around the clock in the CRRT device. Results: The alarm resolution rate and some of CRRT nursing competency scores in the experimental group were higher than those in the control group. The experimental group was also satisfied with the manual. Conclusion: The study confirmed that the schematized alarm-managing manual can be useful for ICU nurses to resolve alarms and can be used as a guideline. Application of this manual to clinical practices and its use can therefore, be encouraged through continuous education and promotion.

• 한국건설관리학회논문집
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• 제2권2호
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• pp.81-89
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• 2001

건설산업은 생산의 단속성, 시장의 불안정성 등 다른 산업과 비교하여 독특한 특성을 갖고 있다. 이러한 특성으로 인해 건설 공사의 비용은 일반 제조업분야에 비해 실제 투입되는 생산비용을 파악하기가 어려우며 프로젝트별로 많은 차이를 나타낸다. 따라서 건설비용을 표준화하는 것은 매우 어려운 작업이며, 비용의 정확한 측정과 분석은 매우 중요한 의미를 갖는다 본 연구에서는 원가계산에 의한 예정가격 산정시 문제점인 획일적인 비율적용에 의한 기존 간접노무비율 산정기준의 문제점을 완성공사 원가구성 분석자료를 통해 고찰한다. 이상의 분석자료를 바탕으로 합리적인 건설공사 간접노무비율의 산정방법 및 기준을 제시하여 실제공사의 예정가격 작성시 의사결정을 돕고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• 제20권5호
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• pp.82-92
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• 1996

A computer simulation with predict the fuel injection rates and the fuel injection pressure behaviors in diesel engine fuel injection systems would by very useful in designing or improving fuel injection systems. In this paper we developed computer program in order to predict the behaviors of the fuel injection rate and the injection pressure for Electronic Hydraulic Ultra-High Pressure Fuel Injection System. We've applied the continuity and momentum equations for the hydraulic phenomena and the dynamics of individual components of the Electronic Hydraulic Fuel Injection System. To solve all the equations numerically we've applied the Runge-kutta IV method. Water hammer equations were applied for the hydraulic pipe solution, and the method of characteristics was employed in our calculations. The simulation results were compared with the experimental results for: Accumulator pressure, Injection pressure and unjection rate. As a result, The simulation results agree very well with our experimental results. We found that a large accumulator and the high speed solenoid valve were required, and the compression volume of the fuel had to be as small as possible in order to acheive ultra-high pressure fuel injection.

• 한국해안해양공학회지
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• 제12권1호
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• pp.19-26
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• 2000

폭풍발생에 따른 해안종단방향의 표시이동은 경빈과 사구의 침식, 연안사주의 생성등 해안단면변화에 있어 주요한 요인의 하나로 알려져 있다. 그러나 폭풍발생에 따른 표사이동은 표사의 입경, 수면상승높이, 쇄파고 등 많은 요소들에 의해 복합적으로 작용하기 때문에 현재에도 정확한 예측이 어려운 실정이다. 본 논문에서는 해안단면에서의 평형에너지소산개념과 표사량 예측에 있어 주요한 요소인 표사량 파라미터를 차원해석을 통하여 변수화하고 수치모델에 도입하여 폭풍발생에 따른 해안종단방향의 해안단면변화와 해빈침식에 대하여 분석하여 보았다. 해안종단방향의 해빈침식은 단면형상 파라미터, 표사량 파라미터, 수면상승높이에 의해 크게 영향을 받음을 알 수 있다.

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.56-66
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• 1998

The absorption process of water vapor in a liquid film is an important process in LiBr-Water absorption system. The composition of the gas phase, in which a non-absorbable gas is combined with the absorbate, influences the transport characteristics. In the present work, the absorption processes of water vapor into aqueous solutions of lithium bromide in the presence of non-absorbable gas are investigated. The continuity, momentum, energy and diffusion equations for the solution film and gas are formulated in integral forms and solved numerically. It is found that the mass transfer resistance in gas phase increases with the concentration of non-absorbable gas. However the primary resistance to mass transfer is in the liquid phase. As the concentration of non-absorbable gas in the absorbate increases, the interfacial temperature and concentration of absorbate in solution decrease, which results in the reduction of absorption rate. The reduction of mass transfer rate is found to be significant for the addition of a small amount of non-absorbable gas to the pure vapor, especially at the outlet of tube where the non-absorbable gas accumulates. At higher non-absorbable gas concentration, the decrease of absorption rate seems to be linear to the concentration of non-absorbable gas.

• 보건교육건강증진학회지
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• 제21권1호
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• pp.171-182
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• 2004

Objectives： Smoking, especially among youth, has been increasing in Korea. This study was performed to evaluate the effects of a newly developing well-designed packaged smoking prevention program (PSPP) for middle school students and to propose further ideas about the program. Methods： The subjects were middle school students enrolled in one Busan city middle school. The effects of the PSPP were evaluated through intervention and follow-up. The PSPP was executed for 10 hours during the semester of middle school freshmen by the author as a position of health teacher, from 1999. After PSPP, cognitions and experiences about smoking were assessed annually from February, 2000 to 2002 by questionnaire. The responses of the educated group and the non-educated group (enrolled in the school at 1998) were compared through chi-square test and odds ratio (OR) and 95％ confidence interval (CI) using SPSS program (ver 10.0). Results： In the three years' follow-up study on the students enrolled in 1999, the proportion of habitual smoking increased significantly (p＜0.001); freshmen 0.2％, sophmore 1.7％, junior 5.0％. However, these level were lower than the results of national study； freshmen 1.1 ％, sophmorer 6.3％, junior 8.5％. Also, the risk of smoking based on the response of 'smoking is hazardous to my health' increased by higher grading. In the comparison of educated and non-educated group, the proportion of the habitual smoking was significantly lower in the educated group(5.0％) than in the non-educated group(13.5％) (OR [95％CI]＝0.33 [0.20∼0.57]). The response rate of 'smoking is hazardous to my health' was higher (OR [95％CI]＝4.42 [2.52∼7.77]), and that of 'maybe smoking in the future' was lower (OR [95％CI]＝0.43 [0.31∼0.59]) in the educated group than in the non-educated group. Conclusions： Though there is not enough information and it was a relatively short evaluation period, this PSPP is considered to be effective in smoking prevention in middle school students. Interests and continuity would be emphasized for the success of smoking prevention programs for younger subjects.

• 한국산학기술학회논문지
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• 제12권1호
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• pp.91-99
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• 2011

성인학습자는 일반적으로 자기조절학습이 뛰어나 학업성취도와 학업지속성이 높지만, 온라인 교육 환경에서는 오랜 기간 학습의 중단과 과거 집합교육에 익숙하여 성인학습자의 장점인 자기조절학습이 쉽지 않아 학업저하 및 학업포기 현상이 발생되고 있다. 본 연구에서는 자기조절학습과 UDL설계 학습모형을 개발하고 이것을 적용한 e-멘토링 시스템을 구축하였다. 실험결과를 분석하기 위하여 연구자는 H 사이버대학교 신.편입 학습자를 대상으로 통제집단과 실험집단으로 구분하고 집단별 100명을 대상으로 학습동기전략질문지(MSLQ)를 기반으로 총 36문항의 질문지로 구성된 학업만족도 설문조사를 하였으며, 학업성취도와 학업지속성에 대한 영향을 알고자 1학기의 성적, 재등록률, 학습시간을 추출하였다. 상관분석 결과는 실험집단에서 만족도가 높을수록 학업성취도(성적)와 학업지속성(재등록률, 학습시간)이 높음을 보이고 있다 본 연구의 결과로 원격대학교 성인학습자들에게 새로운 형태의 e-러닝 교육 부적응 문제를 해결을 할 수 있는 방향과 기준을 제시할 수 있을 것이다.

• 한국환경과학회지
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• 제25권9호
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• pp.1241-1251
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• 2016

A minimum threshold for the signal to noise ratio ($SNR_{min}$) has to be set in the data processing system of wind profiler radar (WPR). The data collection rate and the accuracy of the WPR wind vector depend on the $SNR_{min}$. The WPR at Uljin is operated with an $SNR_{min}$ of 1 dB which is a relatively large threshold. We found that the accuracy and the continuity of the WPR wind vector with height were directly related to the variability of the SNR and vertical gradient of the squared refractive index. We investigated a quantitative method for determining a new $SNR_{min}$ for the WPR at Uljin and it was evaluated with radiosonde data. The accuracy and continuity of the wind vector from an SNR of less than 1 dB, began to decrease at an altitude of 3.5 km. Most of the SNR values were less than -3.5 dB in altitudes higher than 3.5 km. We retrieved high-accuracy wind vectors at altitudes over 3 km where measurements were deficient with an $SNR_{min}$ of 1 dB.