• Journal of Advanced Marine Engineering and Technology
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• v.28 no.2
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• pp.300-308
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• 2004

The formation mechanism of anodic oxide films on Mg alloys when anodized in NaOH solution. was investigated by focusing on the effects of anodizing potential. Al content. and anodizing time. Pure Mg and Mg-Al alloys were anodized for 10 min at various potentials in NaOH solutions. $Mg(OH)_2$ was generated by an active dissolution reaction at the surface. and the product was affected by temperature. The intensity ratio of $Mg(OH)_2$ in the XRD analysis decreased with increasing applied potential. while that of MgO increased. The anti-corrosion properties of anodized specimens at each constant potential were better than those of non-anodized specimens. The specimen anodized at an applied potential of 3 V had the best anti-corrosion property. And the intensity ratio of $Mg_{17}Al_{12}$/Mg increased with aluminum content in Mg-Al alloys. During anodizing. the active dissolution reaction occurred preferentially in ${\beta}\;phase(Mg_{17}Al_{12})$ until about 4 mins. and then the current density increased radually until 7 mins. The dissolution reaction progressed in a phase(Mg) which not formed the intermetallic compound. which had a lower Al content. In the anodic polarization test of $0.017\;mol{\cdot}dm^-3$ NaCl and $0.1\;mol{\cdot}dm^-3\;Na_2SO_4$ at 298 K. the current density of Mg-15 mass% Al alloy anodized for 10 mins increased. since the anodic film that forms on the a phase is a non-compacted film. The anodic film on the phase for 30 mins was a compact film as compared with that for 10 mins.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.13-15
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• 2011

전원 공급이 제한되거나 전원 공급이 불가능한 소형 요트, 작업선, 바지선 등에도 항해 안전을 위한 다양한 항법장치가 필요하고, 해양사고 발생 시 사고원인을 분석하기 위한 기능이 필요하다. 그러나 기존 상선 및 수상레저용 개별 항법 장치는 고가, 대용량 전원공급, 조작의 어려움, 넓은 설치 공간의 필요 등의 문제점이 있다. 본 연구에서는 3축 반도체 가속도 센서와 3축 반도체 경사 센서 및 다양한 기상 측정 센서와 CCD 카메라, 방수 캡슐에 내장된 메모리 등을 이용한 소형 스마트 항법 장치(Multi-Tasking Integrated Navigation System, MINS)를 설계하였다. 기존에 개발된 다양한 기술과 상용 센서 등을 이용하면 MINS 개발이 가능함을 알았고, 이러한 MINS 개발에 필요한 시스템을 제안하였다.

• Toxicological Research
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• v.4 no.2
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• pp.181-188
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• 1988

This study was carried out to investigate whether the use of the high endotoxin-sensitive or the low endotoxin-sensitive rabbits (New Zealand White strain) are more suited for the pyrogen test regulated by the Korean Pharmacopeia and United State Pharmacopeia. The results obtained were as follows. 1. The ferbrile responese were increased according to increased endotoxin doses used (i.e., 0.1, 1, 5, 10ng/kg) and the febrile responses reached to its maximum between 90 mins and 120 mins after the intravenous injection of endotoxin.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.9
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• pp.663-670
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• 1988

Advances in VLSI technology have made it possible to have a larger number of processing elements to be included in highly parallel processor system. A system with a large number of processing elements and memory requires a complex data path. Multistage Interconnection networks(MINS) are useful in providing programmable data path between processing elements and memory modules in multiprocessor system. In this thesis, the performance of MINS for the star network has been analyzed and compared with other networks, such as generalized shuffle network, delta network, and referenced crossbar network.

• Applied Microscopy
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• v.28 no.3
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• pp.315-328
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• 1998

The present study was carried out to investigate the effect of ultrasonic bath in tissue preparation for transmission electron microscopy. The method used standard reagents and media, and employed ultrasonic bath agitation to accelerate fluid exchange. The liver kidney, stomach and cardiac muscle tissues of male Sprague-Dawley rats were used for the experiment, and the experimental design was divided into 4 groups; The control group using rotators (Traditional method, 1,625 mins) and the three experimental groups using ultrasonic bath (UB) in the primary fixation through the infiltration processes (UB I; 62.5 mins, UB II; 125 mins, UB III; 250 mins). The results were as follows; 1. In the control group, tissues were easily sectioned, and showed well preserved intact membranes, and cell organelles such as mitochondria, lysosome, peroxisome, rough endoplasmic reticulum and smooth endoplasmic reticulum. 2. In the UB treated group I, tissues showed holes due to the inadequate removal of both water and fluids used in the dehydration process. Also the mitochondria of cell organelles, especially, showed swollen intracristal spaces and dense matrices due to poor fixation. 3. In the UB treated group II, tissues showed good preservation of cell organelles and specimen slice sections. Also, no holes were observed. 4. In the UB treated group III, tissues showed leaching of structural components in the cytoplasm, but no holes were observed. In conclusion, the ultrasonic bath procedure takes approximately 120 minutes from specimen fixation to resin infiltration and gives excellent results.

• Safety and Health at Work
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• v.11 no.2
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• pp.207-214
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• 2020

Background: Prolonged sitting at work can lead to adverse health outcomes. The health risk of office workers is an increasing concern for the society and industry, with prolonged sitting work becoming more prevalent. Objective: This study aimed to explore the variation in muscle activities during prolonged sitting work and found out when and how to take a break to mitigate the risk of muscle symptoms. Methods: A preliminary survey was conducted to find out the prevalence of muscle discomfort in sedentary work. Firstly, a 2-h sedentary computer work was designed based on the preliminary study to investigate the variation in muscle activities. Twenty-four participants took part in the electromyography (EMG) measurement study. The EMG variations in the trapezius muscle and latissimus dorsi were investigated. Then the intervention time was determined based on the EMG measurement study. Secondly, 48 participants were divided into six groups to compare the effectiveness of every break type (passive break, active break of changing their posture, and stand and stretch their body with 5 or 10 mins). Finally, data consisting of EMG amplitudes and spectra and subjective assessment of discomfort were analyzed. Results: In the EMG experiment, results from the joint analysis of the spectral and amplitude method showed muscle fatigue after about 40 mins of sedentary work. In the intervention experiment, the results showed that standing and stretching for 5 mins was the most effective break type, and this type of break could keep the muscles' state at a recovery level for about 30-45 mins. Conclusions: This study offers the possibility of being applied to office workers and provides preliminary data support and theoretical exploration for a follow-up early muscle fatigue detection system.

• Journal of Veterinary Clinics
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• v.36 no.3
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• pp.159-165
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• 2019

Pimobendan is an inodilator used to treat canine heart failure, and pentoxifylline is reported to be beneficial for microcirculation and heart disease. The purpose of this study was to evaluate the pharmacokinetic and pharmacodynamic profiles of a novel pimobendan-pentoxifylline liquid mixture after oral administration to dogs. Eight healthy Beagle dogs were included in the study. The dogs were divided into the control group (orally administered water; n = 4) and experimental group (orally administered pimobendan-pentoxifylline liquid mixture [pimobendan 0.25 mg/kg, pentoxifylline 15 mg/kg]; n = 4). Plasma samples were obtained and echocardiographic indices were measured for 24 hours after administration. The concentrations of pimobendan and pentoxifylline were quantified by using a liquid chromatography-mass spectrometer (LC-MS). The elimination half-life ($T_{1/2}$) was $32.96{\pm}9.80mins$ for pimobendan and $29.49{\pm}6.67mins$ for pentoxifylline. The time to reach maximum concentration ($T_{max}$) were $52.50{\pm}31.22mins$ for pimobendan and $41.25{\pm}18.87mins$ for pentoxifylline. The maximum blood concentration ($C_{max}$) was $96.92{\pm}75.64ng/mL$ for pimobendan and $7074.07{\pm}3261.1ng/mL$ for pentoxifylline. Of the echocardiographic indices, fractional shortening (FS) and left ventricular internal diameter at end systole (LVIDs) were significantly altered at 1-3 hours after the administration of pimobendan-pentoxifylline liquid mixture. The pimobendan-pentoxifylline liquid mixture was well tolerated by the dogs, with no adverse effects observed during the study.

• Korean Journal of Exercise Nutrition
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• v.13 no.3
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• pp.211-216
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• 2009

This study was conducted to investigate the changes of exercise-induced stress response with acute anaerobic exercise in elite soccer players of university. The subjects were divided into elite soccer players of university (SG, n=10) and control group (CG, n=10). Subjects were tested three consecutive Wingate test for 30 seconds involving 2 times of 3 mins of resting time. In addition, whole blood and capillary blood were collected at rest, immediately post-exercise and 60 mins. of recovery time. Obtained results were as follows: Evaluated mean power and peak power of SG group was significantly higher than that of CG group in the all phase of Wingate test, respectively (p<.01). Although resting serum TG, TC, HDLC levels were not significant difference between SG and CG group, resting serum glucose of SG group was significantly lower than that of CG group. In addition, serum CRP levels of SG group were significantly lower than that of CG group at rest, immediately post-exercise and 60 mins of recovery time, respectively (p<.01). In serum cytokines, in spite of no significant differences in IL-1β levels between SG and CG group, IL-6 levels of SG group were significantly lower than that of CG group at immediately post-exercise and 60 mins. of recovery time, respectively (p<.05, p<.01). From these results, long-term combination training have a crucial role in amelioration of acute exerciseinduced stress response in elite soccer players.

• The Journal of Korean Academic Society of Nursing Education
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• v.4 no.2
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• pp.249-263
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• 1998

The competence of newly graduated nurses is based on various clinical expriences gained when they were students. Therefore, instructors of nursing students, professors in nursing schools or directors in hospitals must play a critical role in assisting them to obtain various knowledge and experienced nursing skills. The purpose of this study was to investigate nursing care activities and nursing care hours practiced by nursing students in a general hospital. The subject students were total 214 nursing students, 2nd graders(sophomores) and 3rd graders(juniors) from 5 Junior Nursing Colleges in Seoul and they practiced at S general hospital to gain clinical experience. The data were collected for 4 days. The tools for this study were the direct nursing care activity list consisted of 15 nursing areas and the indirect nursing care activity list consisted of 9 nursing areas. The subject students were supposed to record their own score. The results of this study are ; 1. The nursing care hours per nursing student 1) The average total nursing care hours a day per each nursing student are 362.65 mins(6.04hr), the direct nursing care hours per each nursing stuent are 202.09 mins(direct nursing care rate 56.0%) and it is higher than the indirect nursing care hours, 159.75mins(indirect nursing care rate 44.0%). The direct nursing care rate of each student by a team approach in the evening shift(56.3%) is higher than that in the day shift(55.8%). 2) The hours of checking vital signs are the longest(47.35mins) among the direct nursing care activites and next is in order of counseling 8l emotional support, nurse rounds, and accompaning a patient during examination. The hours of reporting are the longest(32.39mins) among the indirect nursing care activites, and next is the activities related to education such as reviewing chart, looking up references, etc. 3) The freqency of checking vital signs practiced by nursing student is the highest(the average of 55.7 times) among the direct nursing care activities and next is in order of nurse rounds, assistance of feeding, and counseling & emotional support. The required time for nursing students to accompany their patient during examination is the longest(20.7mins) and next are in order of restriction on patient' activity, orientated by a head nurse, skin care, sitz bath, bathing & hair shampoo, and assisting with patients' exercise. 2. The nursing care hours per grader 1) The average hours of total nursing care per a nursing student are 369.2mins(6.2hrs) to 2nd graders, 355.9mins(5.9 hrs) to third graders. The direct nursing care rate per each nursing student to 3rd graders(59.3%) was higher than that to End graders(52.8%). 2) For 2nd graders, the highly marked nursing activities are teaching associated with direct nursing care activities such as drawing up papers, looking up references, reviewing charts, and being orientated by staff nurses. For 3rd graders, measurments, observations, and nurse rounds in indirect nursing care activities are taken highly 3) The most frequent practice of the nursing care activites is checking vital signs : 65 times to 3rd graders and 46.5 times to 2nd graders. Our suggestions based on the results of this study are : 1. It is recommanded to repeat the same designed study in a variety of clinical fields for further study. 2. It is recommanded to collect data not by self-record method but by observated method. 3. It is needed for nursing instructors in Nursing Schools and in hospitals to develop the guidelines and check-list of clinical practice courses.

• Journal of Nutrition and Health
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• v.22 no.6
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• pp.457-465
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• 1989

Guar gum, a storage polysaccharide galactomannan was administered to 11 patients with type-II diabetes mellitus for 7 days and 3 weeks. They took 5 grams of guar gum 30 mins before each of three meals daily. The dinner 2-h postprandial values of their blood glucose were significantly lowered (P<0.05) after their guar treatment for 7 days compared with before taking guar gum. The 2-h postprandial values of blood glucose were significantly lowered(P<0.05) after 3 weeks of gual treatment compared with before taking guar gum. In an oral glucose tolerance test, their blood glucose values were significantly lowered at 120 mins(P<0.02) and 180 mins(P<0.05) after guar treatment. Total-lipid(P<0.01) and triglycerides(P<0.02) of their blood were significantly decreased and HDL-cholesterol(P<0.02) was significantly increased after guar treatment. HbA1C was significantly reduced (P<0.05) from 11.3% to 10.1% The body weight, total-cholesterol and insulin activity of the patients after guar treatment were not significantly changed and the satiety ratings of the patients with guar treatment was not significantly changed and the satiety ratings of the patients with guar treatment was not significantly changed, however, the subjects that answered from 'Want to eat but can wait' to 'No desire to eat' were 81.1%. It is concluded that guar gum improves their carbohydrate and lipid metabolism in Korean type-II diabetic subjects with high fiber diets.