• 대한토목학회논문집
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• 제44권1호
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• pp.117-124
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• 2024

가치공학(VE; Value Engineering)은 최적의 생애주기 비용으로 최상의 가치를 실현하는 것으로 준비단계(Pre-Study), 분석단계(Study), 실행단계(Post-Study) 3가지 단계로 구성된다. 본 연구에서는 VE 준비단계 중 현장방문 시 정보수집 및 분석을 위한 방법을 제안하고자 한다. 드론을 활용하여 생성된 3차원 공간모델은 연구 대상지를 중심에서 또는 외부에서 다양한 각도로 관찰 및 분석을 할 수 있었다. 준비단계부터 현장 방문 시 미시적 관점에서만 가능했던 현장조사는 드론을 활용함으로써 연구 대상지역의 3차원 공간모델링으로 거시적인 관점에서 검토가 가능하였으며, 실제 관측한 공간정보 데이터를 이용하여 설계 VE 워크숍 중에도 실시간으로 정보를 확인할 수 있어 효율적이고 신뢰성 있는 VE 수행을 할 수 있었다.

• 대한간호학회지
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• 제30권4호
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• pp.1055-1065
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• 2000

The purpose of this study was to develop, through the integration of instructional theory, a Courseware and to investigate the effectiveness of a web-based computer assisted instruction(WBI) program for preventing drug abuse, a serious problem for youth problem. During the first stage of this study done "Drug Abuse Prevention" Courseware was developed based on, Gagn & Brigg's instructional design theory, Keller's ARCS theory and the CAI model of Hannafin & Peck. For the second stage, the courseware was used to provide education for students adolescents in drug abuse prevention. This study used an quasi-experimental, one-group pretest-posttest design with a convenience sample of 36 male high school students who were at one high school located in Seoul. Data were collected using self-reported questionnaires which included a learning achievement tool, the Keller's IMMS (Instructional Material Motivation Survey), on attitudes to drug use, and on responses to the WBI instruction. Prior to the experiment, the "drug abuse prevention" learning method and the procedures of the study were explained to the students, and then the learning achievement of the subjects was measured as a pretest. The students were then given 2 weeks WBI utilizing the courseware. A post-test which included the pre-test learning achievement questionnaire and a survey of learning motivation and attitudes toward drug were given two weeks after the education was completed. The data analysis was done using SPSS/PC. Paired t-test was used to analyze the differences between the pre-test and post-test scores for learning achievement. The results of the analysis are as follows: There were significant differences in learning achievement between the pre-test and post-test(t=-18.62, p=0.000). The hypothesis, that learning achievement will be higher, after the class has used the courseware, than before was supported. The scores for learning motivation and attitudes toward drugs were also higher than the results of existing studies. In conclusion, this study suggests that WBI is an effective learning method in the prevention of drug abuse for adolescents as it can be used for self-learning and repeated learning as assisted instruction. Recommendation would be given that further research needs to be develped in the courseware by cognitive learning style and by multimedia courseware and virtual reality system.

• Journal of Advanced Marine Engineering and Technology
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• 제21권1호
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• pp.49-58
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• 1997

The membrane type LNG tank is non self-supporting tank which consists of both primary and secondary membrane supported through the insulation boxes by the adjacent hull struc¬ture. Although the membranes are not structural member. They are subject to periodical cyclic loads due to the thermal expansion and other expansions or contraction of membrane. At the design stage of the tank, an analytical and experimental approach on the fatigue strengths of membrane and its welds is necessary in order to assist the designer and the inpector. In this study the evaluation method of fatigue strength of membrane type LNG tank is pre¬sented with FEM analysis and fatigue test of lap welds and it contains the following:1) The fatigue tests and preparation of design S - N curve for lap welds 2) FEM analysis of test specimens 3) Estimation of cumulative damage factor of lap welds 4) Guideline for inspection of lap welds of membrane type LNG tank As the results of analytical and experimental approaches in this study, the evaluation method of fatigue strengths of membrane type LNG tank is proposed, which is expected to be useful for design and inspection of membrane type LNG tank.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.388-390
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• 2006

This paper presents a hybrid SoC design for phase detection of single tone signal. The designed hybrid SoC is composed of three functional blocks, i.e., an analog to digital converter module, a phase detection module and a controller module. A design of the controller module is based on a 16-bit RISC architecture. An I/O interface and an LCD control interface for transmission and display of phase measurement values are included in the design of the controller module. A design of the phase detector is based on a recursive sliding-DFT. The recursive architecture effectively reduces the gate numbers required in the implementation of the module. The ADC module includes a single-bit second-order sigma-delta modulator and a digital decimation filter. The decimation filter is designed to give 98dB of SNR for the ADC. The effective resolution of the ADC is enhanced to 98dB of SNR by the incorporation of a pre FIR filter, a 2-stage cascaded integrator- comb(CIC) filter and a 30-tab FIR filter in the decimation. The hybrid SoC is verified in FPGA and implemented in 0.35 CMOS Technology.

• 전자공학회논문지
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• 제50권10호
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• pp.207-216
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• 2013

본 연구의 목적은 수면상태 분석을 위한 분류기를 설계해줌과 동시에 생체신호를 기반으로 하여 수면상태 판별에 유효한 주요 특징벡터들을 추출함에 있다. 수면은 인간의 삶에 중요한 영향을 끼친다. 따라서 사람들이 수면부족 혹은 수면장애를 겪게 되면 집중력 감퇴, 인지기능 장애 등의 문제를 가질 우려가 생기게 되므로, 수면단계 판별에 관한 많은 연구들이 이루어지고 있다. 본 연구에서는 피험자가 수면을 취하는 동안 피험자의 생체신호를 획득하였다. 획득 된 생체신호로부터 필터링 등의 전처리 과정을 통하여 특징들을 추출하여 주었다. 추출된 특징들은 유전 알고리즘과 신경망을 결합하여 만든 새로운 알고리즘의 입력으로 사용되었으며, 알고리즘은 수면단계 분석을 위하여 높은 가중치를 가지는 특징을 선택하여 주었다. 이에 따른 결과로 뇌파 신호와 심전도 신호 모두 사용 시 알고리즘의 정확도는 약 90.26%가 나왔으며, 선택되어진 특징은 뇌파 신호의 ${\alpha}$파와 ${\delta}$파의 주파수 파워와 심전도 신호의 SDNN(Standard deviation of all normal RR intervals)이다. 선택된 특징은 수면상태를 분류하는데 중요한 역할을 함을 알고리즘을 반복적으로 수행하여 확인하였고, 이 연구는 추후 수면장애의 진단 혹은 수면분석의 지침을 만드는데 사용가능할 것으로 사료된다.

• 산경연구논집
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• 제10권4호
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• pp.57-66
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• 2019

Purpose - Present study aimed at investigating the factors that may affect consumers' decision confidence and decision comfort inducing choice commitment taken place at the stage of post-decision/pre-outcome. This study explored whether there are positive effects of dominance and instrumentality of chosen product on the decision confidence, and also identified whether there are positive effects of choice easiness and goal achievement-related affect felt at the chosen product on the decision comfort. Research design, data, and methodology - Portable digital camera as experimental product was used. 260 data were collected from college students. Four were removed from the analyses because they did not complete the questionnaire. Eighteen were removed because they indicated not experiencing the camera in the past. 238 data were used at the analyses to verify hypotheses by structural equation model in AMOS 21.0. Results - First, both of the consumers' decision confidence and decision comfort positively affected choice commitment. Second, the dominance as well as the instrumentality had positive impact upon the decision confidence. Third, the choice easiness and goal achievement-related affect felt at the chosen product had positive impact on the decision comfort. In sum, present study identified the mediation roles of the decision confidence in the effects of both dominance and instrumentality of the chosen product on forming choice commitment, and also found the mediation roles of the decision comfort in the effects of choice easiness and goal achievement-related affect felt at the product on forming choice commitment. Conclusions - Focusing on the stage of post-decision/pre-outcome in decision making process, present study contributes to advancing the choice commitment theories by exploring the positive effects of both dominance and instrumentality of chosen product on the decision confidence, and by finding the positive effects of both choice easiness and goal achievement-related affect felt at the chosen product on the decision comfort. Marketers should promote their products' dominance and instrumentality by showing the superior roles of their product attributes in achieving consumption goal, and should help consumers feel comfort by making choice process easier and giving information that could help feel the goal achievement-related affect at their product chosen.

• 한국도시환경학회지
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• 제18권4호
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• pp.401-408
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• 2018

하수처리 공정모델링 소프트웨어인 EQPS(Effluent Quality Prediction System, Dynamita, France)를 적용하여 A하수처리시설 생물반응조 설계의 적합성을 분석하였다. A하수처리장은 친수용수 수준의 목표수질을 준수하기 위하여 이차침전지 유출수 설계농도를 총질소와 총인, 각 10 mg/L, 1.8 mg/L로 설정하여 설계하였다. 4-Stage BNR 공정인 반응조의 체류시간은 총 9.6시간으로 전무산소조 0.5, 혐기조 1.0, 무산소조 2.9, 호기조 5.2시간이었다. 동절기 공정모델링 결과 친수용수 수준의 목표수질을 만족하기 위하여 혐기조의 체류시간을 0.2시간 늘렸고 당초 설계조건이던 외부탄소원 비상시 주입을 상시적으로 주입해야 하는 것으로 조사되었다. 모델링 결과의 왜곡을 배제하기 위하여 소프트웨어 제조사가 제시한 one step nitrification denitrification 모델의 Default 계수를 사용하였다. 공정모델링은 대체적으로 최적의 상태를 제시하기 때문에 생물반응조 여유율을 고려하면 4-Stage BNR의 체류시간은 9.8시간보다 증가시켜야 한다. 하수처리장 설계단계에서 공정 모델링의 정확한 사용은 하수처리장 건설 후 처리성능과 효율의 안정성을 담보할 수 있는 방법이므로 설계단계에서 철저한 평가가 필요하다.

• 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.

• Journal of Korean Biological Nursing Science
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• 제21권3호
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• pp.169-177
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• 2019

Purpose: The purpose of this paper was to identify blood pressure, interdialytic weight gain, thirst and intradialytic discomfort in subjects after applying individual low-sodium dialysis fluid (1,2,3 mEq/L) to hemodialysis patients for 12 weeks. Methods: This study was a non-equivalent pre-post design. For 12 weeks, dialysate concentration was maintained at 1 mEq/L or 2 mEq/L or 3 mEq/L based on average sodium concentration of each individual, and the difference was compared after applying individually. Results: Change in blood pressure significantly decreased in the group where in pre-hemodialysis systolic pressure decreased the gradient of sodium concentration in serum sodium and dialysis solution by 2mEq/L. Interdialytic weight gain, and thirst showed significant decrease in all three groups. But in all three groups, intradialytic discomfort among dialysis showed no significant changes. Conclusion: Although application of low sodium dialysis fluid showed no change in intradialytic discomfort, lowered blood pressure, thirst, and interdialytic weight gain, which could be used for individual showing increased interdialytic weight gain and increased blood pressure. There is need for continued study on this.

• 한국건설관리학회논문집
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• 제4권3호
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• pp.128-136
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• 2003

턴키공사의 업무수행체계는 기본설계, 입찰, 낙찰, 실시설계, 계약, 시공, 사업물 인도와 같은 절차로 구성되어 있다. 턴키발주 공사의 프로세스 중 이러한 설계업무는 일괄계약자인 기존의 건설회사에서 담당하지 않은 생소한 부분의 업무이다 이 중 실시설계 적격자 선정이후단계에서 계약단계까지의 과정에 해당하는 실시설계단계에는 사업내용에 대한 구체적인 조정 및 최종결정과 관련된 업무가 존재하므로 사업성패에 상당히 중요한 단계로 여겨지고 있으나, 기존의 시공단계의 관리업무만을 수행하던 일괄 사업자에게는 현실적으로 다소 생소한 업무분야이다 현재 국내 턴키공사에서는 실시설계단계에 대한 체계적이지 못한 업무관리로 인해 설계변경 요청, 클레임 제기 등이 발생하고 있다. 이러한 원인은 턴키공사라는 실시설계업무에 대한 구체적 문제점 인식과 이에 대한 관리방안이 체계화되어 있지 못함에 기인한다. 따라서 본 연구에서는 턴키수행공사 기존 설계시공 일괄사업 관련문헌 및 선행 연구고찰을 통한 사례조사연구를 설계하고 이를 토대로 현재 공사 중인 현장에 대한 사례조사를 수행하였다. 사례조사 내용을 분석함으로써 현행 턴키공사의 실시설계 주요 관리업무 및 수행상의 문제점을 구체화하였으며, 실제 실시설계 관리업무 담당자들의 개선방향에 의견을 정리하고 이를 통한 실시설계 관리업무에 대한 개선방안을 제시하였다.