• 디지털융복합연구
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• 제11권4호
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• pp.361-368
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• 2013

본 연구에서는 스프린터와 스케이터 패턴을 통합한 PNF 통합 패턴 운동이 만성 요통 노인 환자의 정적 균형과 동적 균형의 변화를 알아보고자 실시하였다. 본 연구는 만성 요통의 질환이 있는 노인 환자 34명을 대상으로 하였고, 34명을 무작위로 각각 PNF 통합 패턴 운동군(17명)과 스위스볼 운동군(17명)으로 나누었다. 운동전후에 정적 균형 능력 측정을 위해 GOOD BALANCE system(Metitur Oy, Palokka, Finland, 2003)을 사용하였다. 동적 균형 능력 측정을 위해 기능적 팔 뻗기 검사(functional reach test; FRT)와 일어나 걸어가기 검사(timed up and go test; TUG)를 시행하였다. 정적 균형 능력과 동적 균형 능력의 거의 대부분의 항목에서 유의한 차이를 나타내었다(p<.05). 군간 비교에서도 다수의 항목에서 스위스볼 운동군과 PNF 통합 패턴 운동군 사이에 유의한 차이를 나타내었다(p<.05). 이와 같은 연구 결과로 볼 때 PNF 통합 패턴 운동은 만성 요통 노인 환자의 균형 능력을 개선시키는데 효과적임을 알 수 있었으며, 임상에서 PNF 통합 패턴 운동을 이용할 수 있는 기초 자료를 충분히 제공하였다고 할 수 있을 것이다.

• Physical Therapy Rehabilitation Science
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• 제6권2호
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• pp.96-104
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• 2017

Objective: The purpose of this study was to investigate the effect of the hip joint strengthening exercises using proprioceptive neuromuscular facilitation (PNF) on the clinical symptoms and the treatment effects in balance, sit to stand, and gait abilities in patients with TBI. Design: A single case study. Methods: A 13-year-old adolescent with quadriplegia and hip joint control impairment participated in this four-week training intervention. The patient, diagnosed with TBI, wastreated with hip joint strengthening exercises using PNF. In the first week, we focused on strengthening the body, relaxing the hip flexors and activating the hip extensor muscles in order to solve the patient's physical function and body structure. From the 2nd and 4th week, we improved the motivation through the task-oriented method, and then weight-bearing training of the right lower extremity was proceeded by kicking a soccor ball with the left lower extremity. The exercises were performed for 4 weeks, 5 days a week, for 60 minutes with the exercise intensity gradually increased according to the subject's physical abilities. Results: As a result of the study, the patient demonstrated improvements in the physical examination, which were evaluated before and after intervention and included the manual muscle test, modified Ashworth scale, sensory assessment, coordination assessment, Berg balance scale, 5-time sit to stand test, and the 10 meters walk test. Conclusions: The results of this case suggest that a hip joint strengthening exercise program using PNF may improve hip control ability, balance, sit to stand and gait ability in a patient with TBI.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.421-428
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• 2011

최근 지구 온난화와 더불어 급격한 기후 변화 등으로 여름철 주간 냉방 수요가 급격히 증가하여 이에 따른 전력 수요량이 증가하고 있다. 또한 주간 전력 피크로 인한 급격한 전력부하 상승은 전력 수급의 불균형을 가져 와 사회적 문제로 대두되고 있다. 이를 위해 개발된 축냉시스템은 전력사용량이 상대적으로 적은 심야시간에 냉열을 만들어 탱크에 저장해 두었다가 그것을 주간 냉방 전력 사용 피크시간에 이용함으로써, 냉동기의 용량이 작아지고 냉동기를 고효율로 운전할 수 있으며, 갑작스런 부하 증가에 적절히 대응할 수 있는 등 여러 가지 장점을 갖고 있다. 이로 인하여 주간전력 피크를 줄여주는 효과를 가진다. 축냉시스템 중 하나인 슬러리아이스형은 슬러리아이스가 과냉되지 않은 작은 입자형태를 갖고 있어 해빙특성이 뛰어나므로 부하변동에 빠르게 반응할 수 있으며, 그 저장과 재생 및 수송 분야에서 그 장점과 기능이 입증되었다. 본 실험에서는 슬러리아이스 생성 효율을 높이기 위하여 역전유동층을 이용하였다. 이러한 역전유동층은 냉각관 표면에 얼음 부착이 심화되기 전에 얼음 입자를 분리시켜 수 내지 수십 미크론 단위(0.1~0.001 mm)의 슬러리아이스를 생성하도록 하였다.

• Journal of Biosystems Engineering
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• 제37권6호
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• pp.373-384
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• 2012

Purpose: In EU, the animal welfare regulations are strengthening. Also, in Korea, for strengthening of animal protection laws, animal welfare farm certification scheme is being prepared to enforce. To get the certification of animal welfare farm, especially for sows, individual specific feeding in sow group is necessary in accordance with the animal welfare regulation. Also, liquid feeding is reported to be more effective for farrowing as well as dry sow. Therefore, in this study, a electronic liquid sow feeder using RFID which could be fed to farrowing sow simultaneously is developed. Methods : We manufactured a prototype of appropriate elements which were evaluated in the preliminary test for selecting RFID tag, supply pump, mixing type, etc. With the prototype, the performance test for liquid feeding gilt was done in group raising training barn. Results : The performance test result shows the C.V.(coefficient of variation) of liquid mixing and feeding is 0.77~1.97% and 2.4~5.3%, respectively, which means the system could feed sows uniformly. The feeding time of pneumatically activated ball valve is 2 seconds per 0.9 kg of liquid feed. The eating time for gilt were 65 seconds in average. Conclusions : The prototype could feed sow uniformly, and deliver the liquid feed 9 times for a sow continuously. Also, total eating time for a sow was 18 minutes in one visit to the prototype of feeding station.

• 한국재료학회지
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• 제15권4호
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• pp.224-232
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• 2005

Dry sliding wear behavior of electro-pressure sintered Fe-Ni and Co-Fe-Ni compacts was investigated. Pin-on-disk wear tests were performed on the sintered Fe-Ni, Co-Fe-Ni disk specimens against alumina $(Al_2O_3)$ and silica $(SiO_2)$ ball counterparts at various loads ranging from 3N to 12N. A constant sliding speed of 0.1m/sec was employed. Wear rate was calculated by dividing the weight loss measured after the test by specific gravity and sliding distance. Worn surfaces and cross sections of them were examined by a scanning electron microscopy, and wear mechanism of the compacts was investigated. Wear characteristics of the compacts were discussed as a function of composition of the compacts. Relationship between the wear rate and mechancial properties of the compact was explored, and effects of the oxide layer that was formed on wearing surface of the compacts on the wear were also studied.

• 대한기계학회논문집A
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• 제26권5호
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• pp.835-842
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• 2002

In this paper, static and fatigue bending strengths and failure mechanisms of CFRP (carbon fiber reinforced plastics) laminates having impact damages have been evaluated. Composite laminates used for this experiment are CF/EPOXY orthotropy laminated plates, which have two-interfaces $[0^0_ 4/90^0_4]_{ sym}$. A steel ball launched by the air gun collides against CFRP laminates to generate impact damages. The damage growth during bending fatigue test is observed by the scanning acoustic microscope (SAM) and also, the fracture surfaces were observed by using the SEM (scanning electron microscope). In the case of impacted-side compression, fracture is propagated from the transverse crack generated near impact point. On the other hand, fracture is developed toward the impact point from the edge of interface-B delamination in the case of impacted-side tension. Eventually, failure mechanisms have been confirmed based on the observed delamination areas and fracture surfaces.

• 전기전자학회논문지
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• 제20권2호
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• pp.200-204
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• 2016

본 연구에서는 유로형(EURO type) 클린 디젤 CRDI(common rail direct injection) 엔진용 오버플로우 밸브 성능 평가 시스템을 구현한다. 친환경 조건에 맞도록 정밀 기능을 구비한 오버플로우를 위해 스프링의 하중을 고려한 구현이 중요하다. 특히 정밀제어에 따른 디젤 차량의 성능평가는 연비 향상과 환경 규제 만족이 필연적이다. 이에 성능평가를 위한 평가 알고리즘의 기본 조건은 100cc 미만에서 3.0 bar, 150 cc 이상에서 3.3 bar, 250 cc이상에서 4.0 bar를 사용하여 시험한다.

• 대한기계학회논문집A
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• 제20권6호
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• pp.1836-1842
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• 1996

In this paper, static and fatigue bending strengths of CFRP(carbon fiber reinforced plastic laminates having impact damage(FOD) are evaluated. Composite laminates used for this experiment are CF/EPOXY and CF/PEEK orthotropy laminated plates, which have two-interfaces[${0^0}_4{90^0}_4}$]$_sym$. A steel ball launched by the air gun colides against CFRP laminates to generate impact damages. The damage growth during bending fatigue test is observed by the scanning acoustic microscope(SAM). When the impacted side is compressed, the residual fatigue bending strength of CF/PEEK specimen P is greater that that of CF/EPOXY SPECIMEN B. On the other hand, when the impacted side is in tension, the residual fatigue bending strength of CF/PEEK speicemen P is smaller than that of CF/EPOXY specimen B. In the case of impacted-side compression, fracture is proposed from the transverse crack generated near impact point. On the other hand, fracture is developed toward the impact point from the edge of interface-b delamination in the case of impacted-side tension.

• Tribology and Lubricants
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• 제24권4호
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• pp.179-185
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• 2008

Microporous polymer lubricants(MPLs) are solid polymer materials containing micropores which are filled with liquid lubricants, and which are molded or formed to suit rolling bearings or other machine parts requiring lubrication. MPLs can be effectively applied to provide long-term, maintenance-free lubrication of a variety of machine elements without fully replacing of oils and greases. The application of rolling bearings packed fully with an MPL could reduce or eliminate the problems such as grease deterioration, leakage, under-lubrication caused by insertion of water or foreign matters under severe operation conditions. This paper discuss the application of MPLs for lubrication of rolling ball bearings. Two different MPLs were synthesized and the features of MPLs were tested. Characteristics of the bearings which are packed fully with synthesized MPLs were investigated using SEM, TG/DSC, extents of oil leakage, OIT, and life time test. After these preliminary tests twelve MPLs were synthesized and evaluated by measuring extents of oil leakage and OIT values. Then synthesis conditions for the optimum MPL were selected by SSRED(Six Sigma Robust Engineering Design) pro gram using extents of oil leakage and OIT values respectively. The optimum MPL by means of OIT value showed higher performance such as long life time and application at higher temperature of $140^{\circ}C$ than previous temperature of $100^{\circ}C$.

• The Journal of Asian Finance, Economics and Business
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• 제6권4호
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• pp.139-145
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• 2019

This study examines the dynamic linkages between food price inflation and its volatility in the context of Sri Lanka. The empirical evidence derived from the monthly data for the period from 2003M1 to 2017M12 for Sri Lanka. The relationship between inflation rate and inflation volatility has attracted more attention by theoretical and empirical macroeconomists. Empirical studies on the relationship between food inflation and food inflation variability is scarce in the literature. Food price inflation is defined as log difference of food price series. The volatility of a food price inflation is measured by conditional variance generated by the FIGARCH model. Preliminary analysis showed that food inflation is stationary series. Granger causality test reveals that food inflation seems to exert positive impact on inflation variability. We find no evidence for inflation uncertainty affecting food inflation rates. Hence, the findings of the study supports the Friedman-Ball hypothesis in both cases of consumer food price inflation and wholesale food price inflation. This implies that past information on food inflation can help improve the one-step-ahead prediction of food inflation variability but not vice versa. Our results have some important policy implications for the design of monetary policy, food policy thereby promoting macroeconomic stability.