• 한국식품과학회지
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• 제38권1호
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• pp.147-151
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• 2006

본 연구에서는 저열량식이요법의 부작용 증세중 체력저하를 개선할 수 있도록 동의보감의 처방중 체력 증진과 연관된 보음(補陰), 보혈(補血) 기능을 갖는 사물탕(四物楊)을 기반으로 하여 개발된 생약 조성물의 체력 증진 기능을 규명하고자 실시하였다. 저열량식이요법의 모델로서 섭취 식이량의 50%를 제한하는 제한식이를 2주간 실시한 결과 제한식이를 섭취한 군은 강제 수영 모델에서 총 수영 시간이 감소하고 근육내 ATP 함량의 감소, 혈액중 젖산 함량의 증가가 나타나 식이 제한에 의해서 체력 감소가 나타남을 확인할 수 있었다. 본 연구에서 사용된 산야초 추출물을 동일하게 식이제한을 한 실험동물에게 섭취시킨 결과 총수영시간의 증가와 근육내 ATP의 증가, 젖산 함량의 감소가 나타나 저열량식이에 의한 부작용인 체력 저하를 산야초 추출물이 완화시킬 수 있는 기능이 있음을 확인 할 수 있었다. 또한, 산야초 추출물의 투여는 체력과 높은 연관성이 있는 것으로 알려진 혈중 IGF-1의 농도를 증가시키는 것이 관찰되어 체력 향상에 도움을 주는 것으로 추측된다. 식이 제한 환경에서 나타날 수 있는 천연물 추출물의 독성을 확인하기 위하여 간기능 지표인 GOT, GPT를 측정한 결과 특별한 변화가 나타나지 않아 산야초 추줄물의 안전성을 확인할 수 있었다.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1669-1677
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• 2020

이 연구의 목적은 14주 고유수용성 저항운동이 사회복지시설 이용 여성 노인의 근지구력, 동적 평형성 및 보행능력에 미치는 영향이었다. 이 연구에 참여한 대상자는 평균연령이 70세 전후의 30의 여성 노인을 운동집단 15명과 통제집단 15명으로 구성하였다. 대상자들은 운동프로그램 전과 후에 근지구력(30초 의자 앉았다 일어서기), 동적 평형성(3m 왕복 걷기)과 보행능력(10m 걷기, 400m 걷기)을 검사하였다. 운동집단은 주 3회 60분간 스위스 볼을 이용한 고유수용성 저항운동을 하였다. 연구 결과 하체 근지구력에서는 유의한 개선이 있었고, 동적 평형성을 평가하는 3m 왕복 걷기에서도 유의한 개선이 있었다. 보행능력인 10m 걷기와 400m 걷기에서도 유의한 개선이 있었다. 결론적으로 고유수용성 저항운동에 의한 동적평형성과 보행능력의 개선은 여성 노인의 낙상 관련 가능성을 감소시킬 것이다.

• 정보과학회 논문지
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• 제42권3호
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• pp.379-389
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• 2015

Phase Change Memory (PCM 또는 PRAM), Magneto Resistive RAM (MRAM)과 같은 차세대 비휘발성 메모리가 등장하면서, Dynamic Random-Access Memory (DRAM)을 PRAM으로 대체하는 연구가 활발히 진행되고 있다. 본 논문에서는 PRAM을 메인 메모리로 사용하는 시스템에서 지금까지 널리 사용되고 있는 기존의 조인 알고리즘(블록 네스티드 조인, 소트-머지 조인, 그레이스 해시 조인, 하이브리드 해시 조인)들을 사용했을 때 발생하는 내구성과 성능 문제를 비교, 분석한다. 본 연구의 실험결과에 의하면 기존의 조인 알고리즘들을 PRAM에 맞게 재설계해야 하는 필요성이 제기되었다. 특히, 본 연구는 조인 알고리즘들을 PRAM에 적용했을 때 발생하는 이슈들을 과학적으로 규명한 첫 시도이다. 그리고 기존의 조인 알고리즘들을 PRAM에 적용했을 때 발생하는 내구성과 성능을 비교하기 위한 PRAM 기반의 시스템을 모델링하고 시뮬레이터를 구현한 것에 연구의 의의를 둘 수 있다.

• Tribology and Lubricants
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• 제36권2호
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• pp.75-81
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• 2020

In this paper, we present an experimental investigation of the leakage and endurance performances of mechanical face seals in a 75-tonf turbopump for the Korea Space Launch Vehicle II first-stage engine. A mechanical face seal is used between the fuel pump and turbine to prevent mixing of the fuel and turbine gas. However, excessive leakage occurs through the carbon attached to the mechanical face seal bellows. To reduce this leakage, we redesign the mechanical face seal such that the contact area between the fuel and carbon is reduced, height of the carbon nose is reduced, and stiffness of the bellows is increased. Then, we conduct static and dynamic leakage tests and endurance tests to compare the performances of the original and modified mechanical face seals. The investigation of the leakage of the old and new mechanical face seals confirms that the leakage performance is significantly improved, by 80%, in the new design in comparison with the old design. The endurance tests demonstrate that the average wear rate of carbon in the new mechanical face seal is 0.1094 ㎛/s. The service lifetime is predicted to be 4,200 s, which is 28 times greater than the requirement. Finally, we present a new mechanical face seal in a 75-tonf turbopump, and perform a validation test in the real-propellant test facility at the NARO Space Center. Based on the test results, we can confirm that the modified mechanical face seal works well under real operating conditions.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.388-395
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• 2013

PURPOSE. The purpose of this study was to estimate the effects of occlusal stability to identify action mechanisms of mouthguards, known to have a modulatory effect on limb muscle function. MATERIALS AND METHODS. This study included 20 male subjects to perform the isokinetic muscle tests and the Wingate anaerobic power test on both knee joints under five closed-mouth conditions: without or with 4 types of mouthguards with thickness of 2 mm based on premolar area: (1) full-coverage, (2) anterior partial-coverage, (3) right posterior partial-coverage, and (4) left posterior partial-coverage. The obtained results were subjected to One-way ANOVA with repeated measures, followed by post hoc test of the contrast method (${\alpha}$=.05). RESULTS. There was no significant difference between the closed position with and without a full-coverage mouthguard in all variables. However, significant differences were observed between with and without a partial-coverage mouthguard in muscular endurance during extension of the left knee, muscular power and endurance during flexion of the right knee. Additionally, significant differences were found between occlusal states with full- and partial-coverage mouthguards in muscular power and endurance during extension of the left knee. CONCLUSION. These findings indicate the elevation of vertical dimension by 2 mm or the inducement of occlusal stability had little effect on isokinetic muscle strength and anaerobic performance, while uneven distribution of occlusal force might have some positive effects.

• 한국구조물진단유지관리공학회 논문집
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• 제10권2호
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• pp.143-152
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• 2006

건축물의 초고층화에 따라 최근 고성능 콘크리트의 사용이 증가하고 있다. 이러한 고성능 콘크리트는 고강도, 고유동, 고내구성 등 다양한 성능을 발휘하지만, 화재시 폭열에는 약한 것으로 알려져 있다. 본 연구는 PP섬유 혼입 및 마감재 변화에 따른 고성능 RC 기둥의 폭열방지 성능을 검토한 것이다. 실험결과 내화시험 후 폭열특성으로, 먼저 플레인의 경우 심한 파괴 폭열과 함께 철근이 노출됐고 내화뿜칠로 마감한 고성능 콘크리트는 내부 수분의 영향으로 플레인보다 더욱 심한 폭열을 나타냈다. 또한, 마감재 변화에 따른 시험체의 폭열특성으로는 내화도료로 마감한 경우가 가장 우수한 폭열방지 효과를 나타냈으며 폴리프로필렌 섬유를 0.1%혼입한 콘크리트는 3시간 가력 내화시험 후 가장 안전한 폭열방지 성능을 입증하였다.

• 대한물리치료과학회지
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• 제29권1호
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• pp.47-54
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• 2022

Background: Plyometric exercise is an exercise exerting forceful power in a brief period using isotonic activation. It is effective to improve reaction of muscle, agility, endurance and athletics performance. Weight training is an exericse improving muscular strength, endurance and respirating ability applying diversely in frequency and load of exercise Plyometric exercise and Weight training is to facilitate the athletics performance though improving the function of lower limb muscle, there is a difference that Plyometic jump squats is the way to improve agility and Weight training is the way to improve muscular strength. Therefore, it is necessary to know how this difference effects on athletics performance as measuring ankle, ROM, and jumping ability. Design: Randomized controlled trial. Method: This study was conducted with the voluntary participation of 40 university students, who were randomly assigned to jump squat and calf raise groups (n=20 per group). For each subject, we measured the range of motion of the ankle joint before and after exercise, as well as a standing broad jump and vertical jump test performance. We compared the performance indices before and after exercises using paired t-tests, and between groups using independent-samples t-tests. Conclusions: Both jump squat and calf raise exercises improved ankle joint dorsiflexion and plantar flexion, as well as standing broad jump and vertical jump height performance. However, there were no significant differences before versus after exercise, or between exercise types. Although jump squats and calf raises have different purposes, it is thought that, in combination, these exercises improve performance more effectively than either alone, and that such a combined exercise program improves the quality of training in both the general public and athletes in various sports.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.775-776
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• 2012

• 대한물리치료과학회지
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• 제8권1호
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• pp.745-758
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• 2001

The purpose of study to phenomenological examine and the mechanism regarding the gene(DNA, RNA, Protein) and sports to studied, analyzed. and evaluated. This review considers the evidence for genetic effects in several determinants of endurance performance and resistance performance, namely: body measurements and physique, body fat pulmonary functions, cardiac and circulatory functions, muscle characteristics. substrate utilization, maximal aerobic power and other. Moreover, the response to aerobic training of indicators aerobic work metabolism and endurance performance is reviewed, with emphasis on the specificity of the response and the individual differences observed in training ability. This study indicate that improvement of 'Enhancer Action' in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. and think that occurred with exercise influence on skeletal muscle into cell have to Myosin Heavy Chain (MHC) changed was after exercise performance, which accompanied into skeletal muscle that were exercise-induces gene-modulation that is, take gene mutations. This study known that existed hormone(epinephrine)-immune system with interaction. Exercise were altered insulin binding and MAP Kinase signaling increased into immune cells. This review suggested that the high rate of glutamine utilization by cells of the immune system serves to maintain a high intra cellular concentration of the intermediates of biosynthetic pathways such that optimal rates of DNA, RNA and protein synthesis can be maintained. In the absence of glutamine, lymphocytes do not proliferate in vitro: proliferation increase greatly as the glutamine concentration increase. Glutamine is synthesized in skeletal muscle. Skeletal muscle and plasma glutamine levels are lowered by sepsis, injury, bums, surgery and endurance exercise and in the overtrained athlete. The study of result show that production of ET-1 is markedly increased tissue specifically in the heart by exercise without appreciable changes in endothelin-converting enzyme and endothelial receptor expressions, suggest that myocardial ET-1 may participate in modulation of cardiac function during exercise. Conclusionally, this study indicate that improvement of 'Enhancer Action' in RNA genes changed by exercise or sports. Moreover exercise was effect on Central Dogma with DNA makes RNA makes Protein. This study is expected to contribute the area of sports science, medicine, hereafter more effort is required to establish the relation between gene alters and exercise amount.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.349-352
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• 2007

Asphalt overlay resurfacing techniques have been widely utilized in maintaining asphalt concrete in Korea, causing severe traffic congestions while being in construction and difference in level due to the repeated overlay. Besides on these technical difficulties, there have been financial disadvantages associated with technique, mainly because overlay method has been executed for pavements with intact foundations, which is contrary to the norm. This study is aiming to increase the expected life length of the asphalt pavement up to the endurance period, to raise the efficiency of the pavement by maximizing the social benefit and to enhance public character of the street through combining ceramics with epoxy resins, which has advantages in compatibility with the existing pavement materials, durability to abrasion and endurance. It has been expected that the adoption of new method and pavement materials to the actual work sites will develop the performance of the pavements, and to lengthen the durability of the existing materials. The other advantages of the 'thin surfacing' method could be the improved adhesiveness, waterproof, corrosion-proof and bending strength.