• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1261-1265
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• 2003

Axial piston pumps of bent axis have been commonly used in hydraulic systems because of high pressure level. best efficiency, low shear force on pistons and low operating costs. The other side, they have a few demerits like that they have the relatively high number of moving parts and more discharge pressure ripples. Especially, the discharge pressure ripples bring about vibrations and noises in hydraulic system components such as connecting pipes and control valves, so that these deteriorate the stability and accuracy of the systems. Therefore, the hydraulic systems having the axial piston pumps of bent axis require the methods to reduce the discharge pressure ripples. So, the purpose of this paper is to reduce the discharge pressure ripples by the phase interference of pressure wave and to develope the analysis model of the pumps to predict the discharge pressure ripples. In this paper, the analysis model of the axial piston pumps of bent axis was developed using the AMESim software, and the reliability of that was verified by the comparison with the experimental results. The hydraulic pipeline with a parallel line was used as the method to generate the phase interference of pressure wave. the dynamics characteristics of the hydraulic pipeline with a parallel line were analyzed by a transfer matrix method. the usefulness of the phase interference of pressure wave was investigated through the experiment and simulation. The results from the experiment and simulation said that the phase interference of pressure wave by the hydraulic pipeline with a paralle linel could reduce the discharge pressure wave of the pump well. The analysis model of the axial piston pumps of bent axis developed in this paper and the method of the phase interference by the hydraulic pipeline with a parallel line are expected to be helpful to achieve the design of the pump and to reduce the discharge pressure wave of the pump effectively.

• 대한기계학회논문집B
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• 제40권6호
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• pp.373-381
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• 2016

본 연구는 고 레이놀즈 영역에서 후류측에 분리된 분할판(Detached splitter plate)을 가진 원주의 유동장 특성을 양 항력측정 실험과 PIV를 이용한 가시화 실험으로 파악한 것이다. 실험파라메터는 원주 한변의 길이에 대한 분할판의 폭비(H/B=0.5~1.5) 및 원주 후면에서부터 분할판의 앞전까지의 거리(G/B=0~2)로 했다. 분할판의 폭비를 고정시킨 경우 원주의 항력감소율은 간격비가 증가할수록 증가한 후 감소하는 특성을 보였다. 또한 같은 간격비에서는 분할판의 폭비가 클수록 원주의 항력감소율이 컸다. 분리된 분할판의 설치에 의해 분할판의 상, 하부에는 서로 반대방향의 볼테스가 발생되었고, 이 볼텍스가 원주 후류측에 역류를 발생시켜, 원주에 작용하는 항력을 감소시켰다.

• 대한한방내과학회지
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• 제19권1호
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• pp.524-552
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• 1998

Purgation therapy has played an important role as a influential remedy from the begining of the Chinese medicine. Especially purgation therapy is raised as the effective remedy on the acute infectious disease in the book of 'Treatise on Febrile Disease'. But It was inclined to cold-nature and available only in the excess syndrome. Nevertheless it is evident that the book has showed an example of this therapy. During the middle age, purgation therapy is classified into several subtype; hydrogogue therapy, laxation with lubricants, purgation with cold-natured drugs and purgation with warm-natured drugs. Comparing with the ancient times, it must be a progression. It was investigated earnestly by a school leaded by Zhang Congzheng. They were not restricted to several diseases, but applied it to the wide range of diseases. They thought as following. 'One is ill from pathogenic factor so that you should eliminate it from the human body'. Hence, they frequently used three major remedies such as diaphoresis, emesis and purgation. In this process, purgation therapy had showed eye-opening progress. But opposition to it was not little. Li Gao was a representative man on the opposite side. He expressed a critical opinion and placed great importance on the genuine energy, the natural healing force. Under his influence, a large number of doctors evaded purgation and put it under taboo. On account of these trend, purgation therapy had took a backward step and retrograded. Therefore cathartics such as Rhei Radix et Rhizoma, Rharbitidis Semen, cold drugs such as Gypsum Fibrosum, etc. had been excluded for preservation of the genuine energy, and came about an obnoxious custom to value only 'tonity deficiency', or 'warm and tonify'. As it had came into fashion to approach most disease from the point of view, purgation therapy was merely fall into a remedy of constipation. After the eighteenth century purgation therapy encountered the new period of rivival. It was introduced by them who strived for the study of Epidemics to the new current of thought, so called '增水行舟'. It was because 온병 was apt to dissipate one's Yin fluid. Therefore purgation therapy of this period was characterized by establishing nourishment Yin and body fluid with or without use of timely purgation of accumulation of heat. From the time of Zhang Congzheng, it was accomplished by Lee Je-ma to the most epoch-making change. He caused an improvement in the use of purgation therapy by regarding innate constitutional contradiction as importance than representing clinical symptoms. He warned that existing remedies that depend only upon symptoms and signs, not upon individual characteristics including constitutional features didn't bring round to but kill them. And he understood all the pathologic processes in his constitutional theory, investigated specific drugs on four constitution, made indications of each prescriptions clear. For giving to differentiation of constition before differentiation of syndrom, his new slant on the pathologic phenomena overcome the limitations of 변증시치, and revaluate purgation therapy from remedy impaire the genuine energy to that restore it by recover the balance between the internal organ. It is the product of him to fundamentally upset the cause to be in disregard of purgation therapy.

• 한국운동역학회지
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• 제25권3호
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• pp.311-322
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• 2015

Objective : The purpose of this study was to investigate the effects of landing height and knee joint muscle fatigue on the movement of the lower extremity during cutting after landing. Method : Subjects included 29 adults (age: $20.83{\pm}1.56years$, height: $172.42{\pm}9.51cm$, weight: $65.07{\pm}10.18kg$). The subjects were asked to stand on their dominant lower limb on jump stands that were 30 and 40 cm in height and jump from each stand to land with the dominant lower limb on a force plate making a side step cutting move at a $45^{\circ}$ angle with the non-dominant lower limb. The fatigue level at 30% of the knee extension peak torque using an isokinetic dynamometer. Results : The results showed that the difference of landing height increased maximum range of motion and angular velocity of hip, knee, and ankle joints in the sagittal plane, and in the angular velocity of motion of the hip joint in the sagittal plane. The maximum range of motion of the knee joint in the sagittal plane and the frontal plane decreased on landing from both heights after the fatigue exercise. The angular velocity of the hip joint in the sagittal plane, and the maximum range of motion of the hip joint in the transverse plane decreased for both landing heights after the fatigue exercise. The angular velocity of the hip joint in the frontal plane decreased for the 30 cm landing height after the fatigue exercise. On the other hand, the angular velocity and maximum range of motion of the ankle joint in the sagittal plane for both landing heights, and the angular velocity and maximum range of motion of the ankle joint in the frontal plane increased on landing from the 40 cm height after the fatigue exercise. Conclusion : Different landing heights of 30 and 40 cm and 30% fatigue of peak torque of knee extensor found a forefoot and stiff landing strategy, when cutting after landing. These results might be due to decline in the shock absorption capability of the knee joint and the movement capability related to cutting while increasing the contribution of the ankle joint, which may cause increased ankle joint injuries.

• 한국축산식품학회지
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• 제25권4호
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• pp.409-414
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• 2005

The effects of slaughter weight on blood profile and pork qualities of japan berkshires were investigated A total 72 pigs were divided into 3 groups$(125\~130,\;105\~110\;or\;95\~104\;kg)$. At each slaughter weight pigs were conventionally slaughtered and then chilled overnight The carcass characteristics (carcass weight backfat thickness and grades) were determined on those carcass, the muscle longissimus dorsi was removed from each left side at 5th to 13th rib and meat qualities were evaluated. Blood profile including cortisol, creatine phos-phokinase (CPK), lactate dehydrogenase (LDH), glucose and phosphorus was not significantly (p>0.05) different among all slaughter weight, However, the calcium contents of pigs at $95\~104\;kg$ were significantly (p<0.05) higher than the other weights. The carcass weight and backfat thickness of pigs slaughtered at $125\~130\;kg$ were higher than those of $105\~110\;or\;95\~104\;kg$. The carcass grade of pigs slaughtered at $125\~130\;kg$ were significantly (p<0.05) lower than the other weight. The moisture contents of pigs slaughtered at $125\~130\;kg$ were significantly lower than the other weights, but crude protein contents were significantly (p<0.05) higher, Cooking loss and shear lone values of pigs slaughtered at $95\~104\;kg$ were significantly (p<0.05) lower than the other weight. CIE $a^*\;and\;b^*$ values of pigs slaughtered at $105\~110\;kg$ were significantly higher than the other weights. These results imply that the carcass characteristics (carcass weight and backfat thickness) could be affected by slaughter weight the cooking loss and shear force values of pigs slaughtered at $125\~130\;kg$ resulted in higher than those of $105\~110kg\;or\;95\~104\;kg$.

• 한국축산식품학회지
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• 제27권2호
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• pp.137-141
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• 2007

본 연구는 버크셔종의 성별에 따른 육질 특성을 파악하고자 실시되었으며, 60일령의 Berkshire 40두를 2 돈방에 암컷과 거세돼지 각각 20두씩 배치하여 출하 시(약 110 kg)까지 비육한 후 도축하여 실험에 공시하였다. 일반성분은 성 간에 차이를 보이지 않았고, pH는 암퇘지보다 거세돼지가 높게 나타났다(p<0.05). 보수력, 가열감량, 전단가 및 콜레스테롤 함량은 성 간에 차이를 보이지 않았다(p>0.05). 육색의 밝기를 나타내는 명도는 암퇘지보다 거세돼지가 높게 나타났으나(p<0.05), 적색도와 황색도는 유의적인 차이를 나타내지 않았으며, 지방색도 성 간에 차이를 보이지 않았다(p>0.05). 돈육의 물리적인 특성 중 표면경도, 경도, 검성은 암퇘지보다 거세돼지가 더 낮게 나타났으나(p<0.05), 응집성, 탄력성 및 씹힘성은 성 간에 유의적인 차이는 나타나지 않았다(p>0.05). 종합적으로 볼 때 암퇘지에 비해 거세돼지 육이 pH와 명도가 높고 표면경도, 경도 및 검성이 낮아 부드러운 조직을 나타내었다.

• 한국보건간호학회지
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• 제5권1호
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• pp.5-22
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• 1991

This study was conducted to provide information of affective area in developing a nursing curriculum. The sample consisted of 38 sophomores and 43 seniors in Department of Nursing, College of Medicine, Han Yang University. Data were collected by using a structured questionnaire, which consisted of social, home and self control aspects in self concept. The results are summarized as follows; 1. CD In sophomore, as father's academic career were higher, the self concept In social aspects became higher. The students whose father's job was profesion and a white-collar job and who applied for nursing by force and were satisfied with their educational expenses had more positive self concept in social aspects. In senior, as their age were higher, the self concept in social aspects became higher. The students who had religion, recognized the visions of nursing, and were satisfied with their major, had more positive self concept in social aspects. In self concept in social aspects, home environment explained the major variable in sophomore. On the other side, the variable related to major was important in senior. (2) In sophomore, the students who were satisfied with educational expenses and their major had more positive self concept in home aspects. In senior, the students who counseled of their problems with their parents and recognized the visions of nursing had more positive self concept in home aspects. Counsel of their personal problem with their parents explained the most affective variable $(9.6\%)$ for self concept in home aspects in senior. But, it explained only $1.1\%$ of the variance for self concept in home aspects in sophomore. (3) In senior, the students who were unsatisfied with their educational expenses had more negative self concept in self control aspects. 2. There was no significant difference accord ing to the academic year m social, home and self control aspects. 3. The aspects with the highest positive perception of the self concept was home aspects. Self concept in social aspects was more positive perception than in self control aspects. Self concept in self control aspects was lower than in other aspects. 4. Significant relationship a revealed between social aspects and home aspects in sophomore. In senior, the positive correlation were found between social aspects and home aspects and between social aspects and self control aspects. In conclusion, the self concept m home aspects was more positive perception than in other aspects. It resulted from the fact that the nursing uniqueness was based on the spirit of humanity and service. But, when we consider social and self control aspects, good relationship between subjects and nurse is important in nursing, so it is desirable that nursing curriculum include human relationship program. Therefore. in order to strengthen positive self concept, professors and parents must pay attention to student's problems and counsel with then is required.

• 대한토목학회논문집
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• 제33권3호
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• pp.1173-1180
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• 2013

한국의 건설산업은 국가 경제 발전의 중추적인 역할은 해온 기간산업으로서 경제성장의 주요한 동력이 되어 왔다. 건설 산업은 한국 경제 규모의 GDP 대비 15% 이상을 차지해 오며, 70년대 이후의 급속한 근대화와 산업화를 주도하였다. 그러나 이를 위한 성장정책에 따른 부작용은 건설산업 전반에 걸쳐 대두되고 있으며, 그 중 최근의 주목 받은 이슈 중에 하나가 탄소배출권을 중심으로 한 지속가능한 환경구축이다. 이러한 추세에 맞추어 최근 들어 탄소배출절감, 녹색산업화를 슬로건으로 하는 녹색성장이 핵심적인 경제모델로 주목받고 있으며 건설 산업에도 녹색화의 변화가 가속화되고 있는 실정이다. 본 연구에서는 이러한 건설의 녹색화 정책의 핵심 요소 중의 하나인 녹색 인증 제도에 대한 선진국 제도 및 사례 벤치마킹 연구 분석을 수행하였다. 기존의 녹색건설 관련 연구는 주로 건축물을 대상으로 하는 녹색빌딩 부문이 주를 이루어 왔으며, 인프라와 교통시설의 녹색화에 대한 연구는 상대적으로 부족하였다. 이에 본 연구에서는 국내외의 다양한 녹색도로 인증제도에 대하여 조사/분석을 실시하여 향후 인프라 부문의 녹색 건설 정책의 방향성을 제시하고자 한다. 연구의 결과는 국내에서도 추진되고 있는 녹색도로의 인증제도 구축의 기반정보를 제공할 수 있을 것으로 기대된다.

• 한국산학기술학회논문지
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• 제20권12호
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• pp.224-229
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• 2019

본 연구는 고등학교 야구선수를 대상으로 신체정렬과 족저압 분포 분석하여 올바른 자세지도와 스포츠 손상 및 부상 예방 프로그램에 참고 자료를 제공하는데 그 목적이 있다. 연구 대상자 32명을 대상으로 실시하였다. 신체정렬은 척추에서 몸통의 좌우기울기, 등뼈의 뒤굽음각, 허리뼈의 앞굽음각, 골반에서는 골반의 기울기, 골반의 뒤틀림을 측정하였고 족저압은 각 발의 좌우 체중분포, 각 발의 최대압력을 측정하였다. 측정항목에 대한 평균과 표준편차를 산출하여 도표화하였고, 신체정렬과 족저압 분포의 상관관계를 알아보기 위해 pearson's cerrelation analysis를 사용하여 분석하였다. 모든 통계학적 유의 수준은 0.05로 설정하였다. 신체정렬과 족저압 분포 간의 상관관계를 분석한 결과 척추에서 허리뼈의 앞굽음각과 좌우 최대압력에서 양의 상관관계가 나타났다. 몸통의 좌우기울기, 등뼈의 뒤굽음각, 골반의 기울기, 골반의 뒤틀림과 각 발의 좌우 체중분포, 각 발의 최대압력에서는 상관관계가 나타나지 않았다. 본 연구를 통해 허리뼈의 앞굽음각이 증가될수록 발의 한쪽에 힘이 더 실리게 되어 최대압력이 증가하는 양의 상관관계를 나타내는 것을 알 수 있었다. 향후 운동선수들의 신체정렬과 족저압 분포에 대한 운동프로그램의 참고 자료가 될 것으로 사료된다.

• 수산해양기술연구
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• 제29권3호
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• pp.200-213
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• 1993

A model experiment on a midwater rope trawl net which is used in the North Pacific to catch alaska pollack is carried out in the circulating tank to examine the basic efficiency of the net. The prototype is the net used by M/S Hanil(1, 179GT, 2, 700PS), a Korean trawler. The model net was made according to the Tauti's Similarity Law of Fishing Gear in 1/100 scale by considering the condition of the tank. To measure the basic efficiency of the standard model net, the vertical opening and width between some points marked on the net were measured, and the hydrodynamic resistance were determined. Then the constructive conditions of the net were varied as follows and the factors were measured again to compare the efficiency of those nets with that of the standard net(A-1 type) front weight multiplied 1.5 times: A-2 type. buoyancy and depressing force multiplied 1.7 times: A-3 type. front weight multiplied 1.5 times on A-3 type: A-4 type. depressors rigged at ground rope: B type. cod-end stuffed with cashmylon wad: C type. The results obtained can be summarized as follows: 1. The vertical opening at the center of head rope was steeply decreased with the flow velocity increasing and the vertical opening H(m) can be expressed in H=1.2v super(-1.2)(v : flow velocity in m/sec). The width of the net varied a little when the flow velocity was over 0.4m/sec, and the width of net mouth showed about 37% of the distance between the fore tips of net pendant. The shape of net mouth was almost a circle at 0.2m/sec and then steeply flatted elliptically with the flow velocity increasing and the area of mouth S(m super(2)) can be expressed in S=(1.65-2.3v)$\times$10 super(-2). The hydrodynamic resistance of the net increased almost linearly with the flow velocity increasing and the resistance R(kg) can be expressed in R=3.2$\times$d/l$\times$abv. where d/l denotes the mean of d(diameter of netting twine) and l(length of a leg in a mesh) from wing tip to the end of bag-net except cod-end on the side pannel, and a denotes the strectched circumference of the net at the fore end of a meshed part and b the stretched length of the whole net from wing tip to the end of cod-end. 2. In the condition-varied nets, the vertical opening of head rope showed some increase in every type net except the C type, and the increase showed the greatest in the B type by 30~54%, whereas it showed decrease in the C type by 5~10%. Variation of the area of net mouth showed almost the same tendency as the vertical opening and the increase showed the greatest in the B type by 20%, whereas it showed decrease in the C type by 12%. Hydrodynamic resistance showed some increase in every type compared with the standard net, and the rate of increase indicated 5~10% in the A-2, A-3 and A-4 type, 22% in the B type and 3% in the C type.