• 한국자기학회지
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• 제5권5호
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• pp.507-510
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• 1995

A heat-treatment method of pre-annealing and then flash annealing(FA) has been used to improve the soft magnetic properties of nanocrystalline $Fe_{76}CuSi_{13}B_{10}$ and $Fe_{74}CuNb_{3}Si_{12}B_{10}$ alloys. Outstanding magnetic properties of nanocrystalline $Fe_{74}CuNb_{3}Si_{12}B_{10}$ alloy were attained by flash-annealing in air after annealed at $500^{\circ}C$ for 0.5hr below the crystallization temperature. The same results were obtained for $Fe_{74}CuSi_{13}B_{10}$ alloy. The measurment of relief of stress and X-ray diffraction were used to analyze the effect of flashannealing.

• Structural Engineering and Mechanics
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• 제87권6호
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• pp.575-583
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• 2023

The postoperative period for a carrier of total hip prosthesis (THP), especially in the first months, remains the most difficult period for a patient after each operation, even if traumatologist surgeons want the relief and success of their operations. In this investigation, selected three of the daily activities for a wearer of total hip replacement (THR), such as sitting in a chair, lifting a chair, and going downstairs, and was performed a numerical simulation by finite elements based on experimental data by Bergmann (Bergmann 2001) in terms of effort for each activity. Different stresses have been extracted, and a detailed comparison between two activities with different induced stresses such as normal, tensile, and compressive shear stresses.

• International Journal of Advanced Culture Technology
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• 제11권4호
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• pp.449-455
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• 2023

The purpose of this study is to explore adolescent depression, increase understanding of social problems, and develop prevention and intervention strategies. As a research method, social big data was used to collect information related to 'youth depression', and related factors were identified through data mining and analysis of related rules. We used 'Sometrend Biz Tool' to collect and clean data from the web and then analyzed data in various languages. The study found that online articles about depression decreased during the school holidays (January to March), then increased from March to the end of June, and then decreased again from July. Therefore, it is important to establish a government-wide depression management monitoring system that can detect risk signs of adolescent depression in real time. In addition, regular stress relief and mental health education are needed during the semester, and measures must be prepared to deal with at-risk youth who share their depressed feelings in cyberspace. Results from these studies can be expected to provide important information in investigating and preventing youth depression and to contribute to policy development and intervention.

• 한국지능시스템학회논문지
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• 제26권3호
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• pp.226-232
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• 2016

효율적으로 수학 및 과학 성적 향상을 위해서는 뇌 체조 및 스트레스 해소 및 감성 조명이 효과적이라는 연구가 이루어지고 있다. 이러한 원리는 과학 과목은 뇌파가 안정되고, 수학문제를 풀 경우에, 스트레스를 최소화 하고 안정감을 느낄 정도의 편안한 조도를 유지 시키면, 두뇌 회전을 빠르게 수행 한다는 연구 결과를 기반으로 이루어지고 있다. 본 논문에서는 과학 및 수학 학습을 효과적으로 하기위해서, 스트레스 치료 및 음악치료를 이용해서, 최적의 학습조건 모의실험을 하였다. 그러나, 사용자의 취향에 따라서, 좋아하는 음악이나 색깔은 많은 차이점이 있다. 그러므로, 본 논문에서는 이러한 문제점을 해결하기 위해서, 최적의 조명 치료및 음악치료를 제안하고 모의실험 하였다.

• 대한기계학회논문집A
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• 제35권10호
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• pp.1145-1153
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• 2011

본 연구의 목적은 극저온 열처리를 통해 Al6061 의 열처리 잔류응력을 제거하는 것이다. 이를 위해 유한요소해석을 이용하여 열처리 잔류응력을 예측하였으며, 열처리 조건에 따른 각 단계별 대류 열전달계수를 T6 와 극저온 열처리 실험을 수행하여 결정하였다. 예측된 잔류응력 결과는 X 선회절법(XRD)으로 측정된 잔류응력 결과와 비교하여 유한요소해석 결과의 타당성을 확인하였다. 또한 T6 와 극저온 열처리에 대해 각각 전기 전도도와 경도를 측정하여 기계적 특성을 평가하고 TEM 관찰과 XRD 회절 분석을 통해 석출물의 크기 및 성분을 파악하였다. 이를 통해 Al6061 의 T6 열처리와 비교하여 극저온 열처리를 적용함에 따른 잔류응력, 기계적 특성 및 미세조직변화를 조사하였다.

• Child Health Nursing Research
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• 제4권1호
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• pp.128-149
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• 1998

Cigarette smoking has been identified as the single most important source of preventable morbidity and mortality. Smoking behavior varies each individual, so individuality & subjectivity of smoking behavior must be specially focused upon to understand smoking behavior. The purpose of this study was to find attitudes of university students in the prediction of smoking behavior. Q-Methodological method was used as a research design and data were collected during the period from Jan.1, 1997 to Feb. 28, 1998. As the research method, Q-statements were collected through in- depth interviews and a literature review. For the study 33 Q-statements were selected. There were 45 university students as subjects for the research. The 45 university students sorted the 33 statements using the principle of Forced Normal Distribution. The principle of Forced Normal Distribution, which has nine scales to measure the individual opinions, Pc Quanl program was used for analysis and Q-factors were analyzed by using principal component analysis. According to the results of this study, there were four categories of opinion about the smoking behavior in university students. The first type is seeking the habitual dependency. The second type is seeking the stress relief : The third type is seeking the active disapproval : The fourth type is seeking the self control. As a result, The meaning of the smoking behavior is affected by perceived subjective experience, so we need to understand each persons meaning of the smoking behavior and to develop appropriate nursing interventions based on the typology of smoking behavior. Finally, The result of the study will provide basic data for smoking prevention and cessation program.

• 한국정밀공학회지
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• 제28권3호
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• pp.357-362
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• 2011

Air springs are prevalently used as suspension in train. However, air springs are seldom used in automobiles where they improve stability and comfort by enhancing the impact-relief, breaking, and cornering performance. Thus, this study proposed a new method to analyze air springs and obtained some reliable design parameter which can be utilized in vehicle suspension system in contrast to conventional method. Among air spring types of suspension, this study focused on sleeve type of air spring as an analysis model since it has potential for ameliorating the quality of automobiles, specifically in its stability and comfort improvement by decreasing the shock through rubber sleeve. As a methodology, this study used MARC, as a nonlinear finite element analysis program, in order to find out maximum stress and maximum strain depending on reinforcement cord's angle variation in sleeves. The properties were found through uniaxial tension and pure shear test, and they were developed using Ogden Foam which is an input program of MARC. As a result, the internal maximum stresses and deformation according to the changes of cord angle are obtained. Also, the results showed that the Young's modulus becomes smaller, then maximum stresses decrease. It is believed that these studies can be contributed in automobile suspension system.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.75-80
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• 2004

Vehicle structures are composed of many substructure connected to one another by various types of mechanical joints. In vehicle engineering it is important to study these connected structures under various dynamic forces for the evaluations of fatigue life and stress concentration exactly. It is difficult to obtain the accurate load history of specified positions because of the errors such as modeling, measurement and etc. In the beginning of design exact load data are actually necessary for the fatigue strength and life analysis to minimize the cost and time of designing. In this paper, the procedure of practical dynamic force determination is developed by the combination of the principal stresses of F. E. Analysis and experiment. Least square pseudo inverse matrix is adopted to obtain in inverse matrix of analyzed stresses matrix. The error minimization method utilizes the inaccurate measured error and the shifting error that the whole data is stiffed over real data. The least square criterion is adopted to avoid these non. Finally, to verify the proposed procedure, a bus is analyzed. This measurement and prediction technology can be extended to the structural modification of any geometric shape in complex structure.

• Current Optics and Photonics
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• 제4권4호
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• pp.293-301
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• 2020

In this paper we propose and theoretically analyze a monolithic multiparametric sensor consisting of a superstructure of surface-relief waveguide Bragg gratings (WBGs), a micro-machined diaphragm, and a cantilever beam. Diaphragms of two different configurations, namely circular and square, are designed and analyzed separately for pressure measurement. The square diaphragm is then selected for further study, since it shows relatively higher sensitivity compared to the circular one, as it incurs more induced stress when any pressure is applied. The cantilever beam with a proof mass is designed to enhance the sensitivity for acceleration measurement. A unique mathematical method using coupled-mode theory and the transfer-matrix method is developed to design and analyze the shift in the Bragg wavelength of the superstructure configuration of the gratings, due to simultaneously applied pressure and acceleration. The effect of temperature on the wavelength shift is compensated by introducing another Bragg grating in the superstructure configuration. The measured sensitivities for pressure and acceleration are found to be 0.21 pm/Pa and 6.49 nm/g respectively.

• The Korean Journal of Pain
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• 제11권2호
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• pp.235-240
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• 1998

Background: Preoperative blocking of surgical nociceptive inputs may prevent sensitization of CNS and reduce postoperative pain. The stress responses to surgical trauma consist of increase in catabolic hormones and decrease in anabolic hormones. We studied whether preoperative intravenous morphine could affect postoperative pain and change plasma cortisol and serum glucose levels. Methods: Thirty eight patients undergoing total abdominal hysterectomy were randomly assigned to one of three groups. Control group (n=11) did not received intravenous morphine, preoperative group (n=13) received intravenous morphine (0.1 mg/kg as a bolus 10 min before operation and followed by 1.5 mg/hr for 10 hours), postoperative group (n=14) received the same doses and method of intravenous morphine of preoperative group postoperatively. Postoperative pain relief was provided with i.v. fentanyl through Patient-Controlled-Analgesia Pump. Postoperative visual analogue scores (VAS), analgesic requirement (first request time, total amounts used), side effects, plasma cortisol and serum glucose levels were compared. Results: VAS were different between control group and the other two goups, but were not different between preoperative and postoperative group. Total amounts of used fentanyl were not different among groups, but first request time were significantly delayed in the preoperative group compared with the other two groups ($66.2{\pm}33.9$ vs $39.0{\pm}15.4$ and $45.0{\pm}14.9$ min respectively, p<0.05). Plasma cortisol and serum glucose levels were not different among groups. Conclusions: Above dosage of preoperative and postoperative morphine has analgesic effect, but could not block surgical stress induced plasma cortisol and serum glucose increase.