• Journal of Advanced Marine Engineering and Technology
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• 제39권5호
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• pp.563-569
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• 2015

A chemical reaction occurring in CSTR (Continuous Stirred Tank Reactor) is significantly affected by the concentration, temperature, pressure, and reacting time of materials, and thus it has strong nonlinear and time-varying characteristics. Also, when an existing linear PID controller with fixed gain is used, the performance could deteriorate or could be unstable if the system parameters change due to the change in the operating point of CSTR. In this study, a technique for the design of a fuzzy PD plus I controller was proposed for the temperature control of a CSTR process. In the fuzzy PD plus I controller, a linear integral controller was added to a fuzzy PD controller in parallel, and the steady-state performance could be improved based on this. For the fuzzy membership function, a Gaussian type was used; for the fuzzy inference, the Max-Min method of Mamdani was used; and for the defuzzification, the center of gravity method was used. In addition, the saturation state of the actuator was also considered during controller design. The validity of the proposed method was examined by comparing the set-point tracking performance and the robustness to the parameter change with those of an adaptive controller and a nonlinear proportional-integral-differential controller.

• 한국생산제조학회지
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• 제9권3호
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• pp.83-89
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• 2000

In hydraulic control system turbine and gear motor type flowmeters are widely used to measure the flow rate under steady flow conditions. With the recent growth of interest in the measurement of instantaneous values of unsteady flow rate the test of the transient response of these flowmeters are in some significance. however an unsteady flow rate mea-surment and its calibration method with a fast response and a high accuracy have not beendeveloped. In this research particularly the dynamic characteristics of turbine and gear motor type flowmeters are investigated experimentally and simple mathematical models are proposed. The measured flow rate waveforms are compared with those by remote instan-taneous flow rate measurement method(RIFM) which has been developed by author and used for calibration As the result of frequency response test gain and phase between the measured flow rate waveforms by turbine type flowmeter and those estimated by RIFM are in good agreement up to 70Hz For the gear motor type flowmeter th simulated results by a math-ematical model proposed here agree well with the experiment nearly up to 100Hz. Also it if sound that the pressure drop across the flowmeter is increased in proportion to the frequency of the flow rate variation in a high frequency region of more than 100Hz. It can be explained that the dealy of gear motor type flowmeter in high frequency regionis mainly attributed to a first order delay consisting of the inertia of gears and internal leakage of the gear motor.

• 한국콘텐츠학회논문지
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• 제15권6호
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• pp.259-266
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• 2015

본 연구는 비만인의 보행과 관련된 근거자료를 제시하고 근골격계 질환 예방을 위한 임상적 자료로 활용하고자 시행하였다. 신체 건강한 여대생 40명을 정상체중집단(20명), 비만집단(20명)으로 분류하여 보행패턴(smartstep), 균형지수(biodex balance SD), 근활성도(surface EMG)를 정량적으로 측정하여 비교하였다. 연구결과, 정상체중집단에 비해 비만집단의 경우 체중으로 인한 압력과 부하를 이겨내고, 체중 증가로 인한 신체 불균형 상태에서 발목관절 움직임을 증가시켜 보행함으로써 발목 움직임에 작용하는 근육의 활성도가 더 높아짐을 알 수 있었다. 따라서 비만인의 하지 근골격계 질환예방을 위해서는 하지 근육의 근력강화 및 지속적인 균형훈련과 보행 훈련이 필요할 것으로 생각된다.

• 대한두경부종양학회지
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• 제33권1호
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• pp.43-45
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• 2017

이하선 기종은 이하선 종대의 원인 중 매우 드문 질환으로, 이하선의 종창과 통증 등의 증상을 나타낸다. 이하선 기종은 유리 부는 직공이나 관악기 연주자 등 여러 구강 내 압력이 증가하는 상황에서 이하선 내로 공기가 들어가 발생할 수 있다. 저자들은 최근 습관적인 볼 부풀리기로 유발된 양측 이하선 기종 환자를 경험하고, 이에 대해 습관 교정을 통한 보존적 치료로 호전되었기에 문헌 고찰과 함께 보고하고자 한다.

• 한국의류학회지
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• 제37권1호
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• pp.113-123
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• 2013

Clothes that retain and emanate body odor feel uncomfortable and unclean; subsequently, the adsorption, desorption and removal amounts of malodorous compounds from fabrics with different polarities were examined. 1-Octen-3-one, octanal and isovaleric acid, which are important malodor compounds from the body, were used as volatile organic compounds (VOC). Samples were prepared with unfinished and ${\beta}$-CD finished cotton, nylon and PET fabrics. The amounts of VOCs retained on the fabrics were measured using headspace GC-MS; in addition, the odor intensity of the samples were evaluated by 10 trained panelists. The amounts adsorbed were estimated by weight gain; however, moisture was found to have a larger effect on the increase in weight than VOCs. The polarity of the VOCs decreased in the order of isovaleric acid, octanal and 1-octen-3-one. Despite the exceptionally large amounts of octanal adsorbed on the nylon sample, the amounts of malodorous compounds adsorbed on fabrics increased with the decreasing VOC molecular weight. The unfinished PET sample adsorbed more VOCs than the unfinished-fabric samples. The odor intensity was mostly weaker in the ${\beta}$-CD finished fabrics than in the unfinished fabrics. The odor intensity of the ${\beta}$-CD finished fabrics was lower than unfinished fabrics. The amount of VOCs that remained on the soiled fabric samples after storing in air for 24 hrs decreased with the increasing VOC vapor pressure. Most VOCs were removed by washing; however, more VOCs were left on the ${\beta}$-CD finished fabrics than unfinished fabrics. The intensity of the odor from the unfinished PET and ${\beta}$-CD finished fabrics was stronger and weaker, respectively, than that of other fabrics, even when the same amounts of VOCs remained.

• International Journal of Fluid Machinery and Systems
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• 제8권4호
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• pp.264-273
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• 2015

This presentation describes an experimental approach for the detection of cavitation in hydraulic machines by use of ultrasonic signal analysis. Instead of using the high frequency pulses (typically 1MHz) only for transit time measurement different other signal characteristics are extracted from the individual signals and its correlation function with reference signals in order to gain knowledge of the water conditions. As the pulse repetition rate is high (typically 100Hz), statistical parameters can be extracted of the signals. The idea is to find patterns in the parameters by a classifier that can distinguish between the different water states. This classification scheme has been applied to different cavitation sections: a sphere in a water flow in circular tube at the HSLU in Lucerne, a NACA profile in a cavitation tunnel and two Francis model test turbines all at LMH in Lausanne. From the signal raw data several statistical parameters in the time and frequency domain as well as from the correlation function with reference signals have been determined. As classifiers two methods were used: neural feed forward networks and decision trees. For both classification methods realizations with lowest complexity as possible are of special interest. It is shown that two to three signal characteristics, two from the signal itself and one from the correlation function are in many cases sufficient for the detection capability. The final goal is to combine these results with operating point, vibration, acoustic emission and dynamic pressure information such that a distinction between dangerous and not dangerous cavitation is possible.

• 디지털융복합연구
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• 제14권1호
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• pp.219-227
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• 2016

본 연구는 다중역할을 하는 간호전문직 기혼 여성의 대학원생활 경험을 이해하고, 그들의 생생한 경험의 의미를 밝히기 위하여 Colaizzi의 현상학적 연구방법을 사용한 질적연구이다. 연구대상은 간호전문직 기혼 여성으로서 대학원에 재학하여 일과 학업을 병행하고 있는 석 박사 과정생으로 이들을 대상으로 반구조적인 개인심층면담을 진행하였다. 연구결과 도출된 5개의 범주는 '시간에 쫓기며 살아감', '심도 깊은 학업 부담감에 짓눌림', '가족에 대한 죄책감', '많은 역할간의 갈등으로 몸부림침', '힘든 가운데 찾은 의미와 보람'으로 나타났다. 결론적으로 현대사회의 급속한 발전과 함께 인간의 건강에 대한 건강문제를 해결함으로써 건강증진에 기여 할 수 있는 전문적인 간호사가 될 수 있도록 다양한 지지체계를 통하여 대학원과정을 배려하고 지지해 준다면 간호학문에 대한 정체성 확립을 돕고 대상자들의 건강증진을 위하여 더욱 전문적인 간호를 할 수 있을 것이다. 본 연구결과는 간호전문직 기혼 여성의 대학원생활에 대한 생생한 경험을 바탕으로 범주화한 결과로 합리적인 중재 방안의 개발에 유용한 기초자료로 이용될 수 있다.

• Preventive Nutrition and Food Science
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• 제13권3호
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• pp.146-156
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• 2008

The enhancement of the human body fat reduction of conjugated linoleic acid (CLA) with the supplementation of $\gamma$-oryzanol (OZ) was investigated on overweight Korean women (n=51, BMI> 23). Subjects were divided into 4 groups of control, CLA, glyceride form of CLA (GCLA), and CLA plus OZ (CLA-OZ). The soft-gel capsule (500 mg) was used to deliver control (500 mg olive oil), CLA (500 mg CLA), GCLA (500 mg GCLA) and CLA-OZ (500 mg CLA plus 50 mg OZ). Three capsules were taken twice a day for 12 weeks. The CLA-OZ supplementation reduced 1.35% body fat that was 0.34% enhancement against CLA supplementation. As considered subject variations, CLA-OZ reduced body fat ranged from 7.9% to -2.7%, equivalent to 5.6 kg loss to 0.7 kg gain in body fat mass, against CLA. The CLA-OZ reduced body weight and body mass index (BMI), relative to control, but the reductions by CLA-OZ were not different from those by CLA and GCLA. All biochemical markers analyzed for safty were not significantly different within or between groups and were within the normal range. The CLA-OZ supplementation significantly reduced blood pressure, as compared to the supplementation of CLA, GCLA and control. These results suggest that OZ could be a useful ingredient to mix with CLA for the reduction of human body fat.

• 기본간호학회지
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• 제7권1호
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• pp.122-136
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• 2000

Stroke patient needs rehabilitation after receiving an acute treatment in a hospital. When stroke patient gets involved in an early discharge program, home care nurse plays a pivotal role to make them to gain a full strength and to come back to his/her prior life before he/she is sick. In spite of the importance of home care nursing intervention protocol for home care nurses to perform home care nursing autonomously, home care nursing intervention protocol for stroke patient is rarely developed. Therefore this study was conducted to develop home care nursing protocol that is applicable for stroke patients in home care nursing area. 41 home care nursing charts for stroke patients registered in home care nursing agencies from December 1st 1994 to August 31st 1999 at Y hospitals in Seoul and Won-Ju city were analyzed. 44 home care nurses who were having over three years' experience on stroke patients were participated in this study as a user validity validation group. The results of this study are as follows. 1. 28 nursing diagnoses were selected on the basis of evaluation of nursing diagnoses of stroke patients presented in a previous literature and case studies on home care nursing. 2. 17 nursing diagnoses were classified through the frequency analysis of home care nursing charts for 41 stroke patients who had received home care nursing. The order of sequence was like these: impaired skin integrity, risk for infection, nutritional deficit, impaired physical mobility, constipation, knowledge deficit, ineffective airway clearance, anxiety in family members, risk for aspiration, self care deficit, altered urinary elimination, ineffective individual coping, social isolation, risk for injury, self-esteem disturbance, impaired verbal communication, fatigue of family caregiver. 3. Based on validation on expert and user validities, 44 nursing interventions which were above ICV=.80 were chosen. 4. Nursing intervention protocols which showed above ICV=.90 were developed and were like these; pressure ulcer care, position change, preventive care for circulatory dysfunction, tube care : catheter, vital sign monitor, constipation/impaction management, artificial airway management, suction of airway secretion, environmental management : safety, and fall prevention.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.672-674
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• 2017

하이브리드 로켓의 연소 실험 과정에서 저 주파수 대역이 증폭하는 연소 불안정이 관찰되었다. 반면, 터빈 연소기에서는 혼합 특성 향상을 통하여 연소의 안정성을 얻기 위해 스월 유동을 사용한다. 본 연구에서는 하이브리드 로켓의 연소 불안정을 감소시키기 위하여 스월 인젝터를 사용하여 실험하였다. 그 결과, 하이브리드 로켓에서 스월 인젝터를 통하여 산화제를 주입한 경우 연소 불안정이 감소하였다. 산화제의 스월 유동의 변화는 연소실 내부의 난류유동 특성을 변화시키며 그 결과, 연소 불안정에 영향을 미친다. 따라서 스월 각도 변화를 통하여 스월 넘버 변화를 변화시킴으로써 유동 특성 변화에 대해 알아보았다. 유동 특성 변화가 주파수 특성에 미치는 영향, 압력진동과 연소진동의 상관관계에 대해 확인하였다.