• 대한인간공학회지
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• 제29권3호
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• pp.279-286
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• 2010

The purpose of this study was to compare the electromyographic(EMG) activities of trunk and hip muscles between right and left sides while subjects performed prolonged manual task in asymmetric and symmetric weight-bearing posture. Fifteen healthy male college students were recruited for this study. The subjects were asked to perform bimanual upper extremity task for 6 minutes in two different standing postures. In the symmetric weight-bearing posture, the subjects were standing with evenly distributed body weights to both legs. In the asymmetric weight-bearing posture, the subjects distributed about 90% of their body weight onto their preferred(supporting) leg and 10% of their body weight onto the opposite leg while they were standing. EMG activities of the right and left internal oblique, erector spinae, gluteus maximus, and gluteus medius were measured and normalized as % MVIC. Then the EMG data were statistically analyzed using paired t-tests. The EMG activities of all measured muscles were not significantly different between the right and left side in the symmetrical weight-bearing posture(p>0.05). However, the EMG of the supporting side internal oblique was significantly lower than the opposite side(p<0.05), and the EMG of the erector spinae, gluteus maximus, and gluteus medius were significantly greater on the supporting side(p<0.05). The results of this study support that unbalanced use of right and left muscle possibly causes the changes in muscle length which results in asymmetry of trunk and hip muscles. Furthermore, the uneven weight support onto right and left legs will cause a distortion of viscoelastic ligaments around hip and sacroiliac joints in the long run. Further studies to determine the effect of various manual tasks on the trunk and hip muscles as well as the effect of asymmetrical weight-bearing standing posture on hip and back muscle fatigue may be required.

• Elastomers and Composites
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• 제47권1호
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• pp.43-53
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• 2012

물을 반응매체로 하고 스티렌과 부틸메타크릴레이트 (BMA)를 단량체로 하여 $65^{\circ}C$에서 $95^{\circ}C$ 사이의 선택된 온도에서 현탁중합을 실시하였다. 소수성 실리카를 안정제로, azobisisobutyronirile (AIBN)을 개시제로 선택하였다. 안정제의 최적 분산은 pH 10에서 이루어졌으며 반응은 pH 7에서 진행하였다. TGA 및 EDS 측정으로 사용한 실리카의 90%는 안정제로 10%는 입자 내로 유입되는 것으로 분석되었다. 안정제의 농도가 증가할수록 평균입경은 감소하였다. 분자량은 안정제의 농도가 1.67 wt%에 이르며 증가하였다. 개시제의 농도 및/혹은 반응온도의 상승에 따라 반응속도는 증가하였으나 분자량은 감소하였다. 입자의 입경은 개시제의 농도 및 반응온도에 거의 무관하였다. BMA의 비가 증가하면서 유리전이온도는 감소하였으며 불규칙한 형상의 입자가 증가하였다. 카본블랙을 함유하는 스티렌/BMA의 중합반응은 반응완료에 보다 많은 시간이 소요되었다. 소수성 실리카를 안정제로 하는 현탁중합반응을 이용하여 카본블랙을 함유하는 평균입경이 $1-30{\mu}m$의 구형 폴리(스티렌-BMA) 공중합체 복합체 입자를 합성할 수 있다는 사실을 확인하였다.

• 물과 미래
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• 제5권2호
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• pp.17-29
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• 1972

The persent study aims at finding out a means of prevention cool spell damages on the hilly areas. The irrigation plots of 24 hour stored water warm water way and warm water plots, cool water way are respectively established to find out water temperature and influnce on the growing rice plants. The results obtained are summed up as follows. 1. Warm water areas consisted of $5 m^2 Q=0.93 1{\ell}/sec$, V=31 cm/sec, S=1/1, 000, L=81.6m, B=5cm, h=6cm, t=4min 33sec, drops=9 areas, are constructed to help the water temperature of $14.5^{\circ}C$ rise to that of $21.6^{\circ}C$. This indicates lower temperature than $23^{\circ}C$ of critical water temperature in irrigation facilities by $1.45^{\circ}C$ and than $26.2^{\circ}C$ of balanced water temperature of Seoul arears by $4.6^{\circ}C$. But this does not give much influance on rice plant cultivation. 2. The rising of water temperature is influened according to the temperature, solar radiation but the water temperature changes according to the heat absorption of organized materials, weather and terraces. The difference of water temperature could be found in the first growing stage. 3. Through the warm water way of water rises to the temperature of $21.6^{\circ}C$ which also rises to the temperature of around $30^{\circ}C$ in the paddy field of submerged irrigation. The rice plants are comparatively free from prolonged cool damage, reproduction abstructive damage. 4. The water temperature in rice field in proportion to temperature influence of weather condition but the water temperature approaches to that of weather in the days of later growing stage and water temperature become lower than the air temperature in the fruit stage. 5. The water in the submreged field is $10^{\circ}C$ warmer than in the warm water way during the first growing stage period but the water temperature in the warm water way is warmer in the later growing stage period. The cool water of $14.5^{\circ}C$ is warmed to $30.1^{\circ}C$ and rice plants cultivation is free from other damages. 6. The 12% increased production or 570.98kg/10a is made cool water plot by rising the temperature of water from $14.5^{\circ}C$ to $21.6^{\circ}C$ making the water run through warm water way. 7. The damage inflicted by the cool water irrigation during the first growing stage period is the obstruction of peak tillering stage and the obstruction of heading the later growing stage period and the obstruction of fruiting and number of panides per fill.

• KDI Journal of Economic Policy
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• 제30권2호
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• pp.61-97
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• 2008

본 연구는 공무원의 전문성 축적을 저해하는 것으로 지속적으로 지적되는 순환보직의 실태를 파악하고 그 개선방안을 제시하는 것을 목적으로 한다. 우리나라 중앙부처 과장급 이상 공무원의 평균재직기간은 1년 남짓으로 매우 짧아 업무의 인수 인계에서 오는 비효율 및 업무공백, 전문성 축적기회의 감소, 책임성 저하, 정책의 일관성 및 연속성 결여 등 여러 문제를 낳으며, 특히 고도의 전문성을 요하는 대외 협상 분야에서 큰 국가적 손실을 낳는 것으로 파악된다. 이의 개선을 위해서는 전문성을 고려하는 보직이동, 전보범위의 축소, 전보제한기간의 강화 등의 조치가 필요하나, 근본적으로 현재와 같은 과도한 순환보직이 연공서열에 기초한 계급제에 기인하므로 장기적으로 공직분류제도를 계급제에서 직위분류제로 전환하고 실적주의적 요소를 강화해야 할 것이다.

• The Korean Journal of Physiology
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• 제7권1호
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• pp.23-31
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• 1973

Numerous factors concern with the absorption of substances through the membrane of the gastrointestinal tract. To simplify the experimental condition, present work has been restricted to observe the disappearance rate of substance from the intestinal loop which was made in the jejunum, 70 cm apart from the pylorus of the adult rabbit. The purpose of the study is to clarify the absorption of urea through the jejunal wall is solely attributable to the concentration difference between the luminal fluid and plasma, and to observe the effect of adding red pepper upon the rate of absorption. The rabbits were anesthetized with nembutal, 35mg/kg I.V. Jejunal loop was made by ligating at 2 spots, 70 cm and 80cm apart from the pylorus. After rinsing with normal saline solution through the polyethylene tubing inserted from the end of the loop, 8 ml of test solution was placed through the same tubing. The test solution contained 200 mg% of urea and 150mg% of polyethylene glycol(M.W. 4,000) in normal saline solution. Right after placing the test solution the first specimen was taken through the tubing, and successive samplings were performed at 5, 10, 20, and 30 minutes. Logarithm of the difference of urea concentration between the luminal fluid and plasma was plotted against time elapsed after the onset of the experiment. If straight line is revealed, it would verify the nature of transport mechanism as diffusion, obeying the Fick's principle. The concentration of polyethylene glycol (PEG) was also measured in order to examine the change in the volume. PEG was used as the marker substance because it is not absorbable in the intestinal tract. Consequently the concentration of PEG relates inversely to the volume of the loop. Instantaneous concentration of urea in the loop times the volume will give the amount of urea remaining in the luminal fluid. The change in the amount of any substance is directly relate to the volume of the compartment and differs from the change in the concentration which is independent of the volume. After completion of the experiment without red pepper, it was added in the test solution and was centrifuged after thorough mixing. Supernatant of the mixture was placed in the loop and similar sampling were performed with the same time intervals that of previous run in order to observe the effects of the red pepper on the passive transport of the water soluble small substance, urea. The results obtained were as follows: 1. Logarithm of the concentration difference of urea between the luminal fluid and plasma was diminished exponentially as time elapsed. The decay constant in the experiment without red pepper was 0.0563/min. By adding red pepper in the test solution as much as the concentration rose to 4,000 mg% and 8,000 mg%, the decay constants were lowered to 0.0493/min and to 0.0506/min, respectively. The time interval by which the concentration difference dropped to one half of the initial value was prolonged. Without red pepper the half concentration time was 13.30 minutes, and by adding extract of red pepper, 15.31 minutes and 15.71 minutes were revealed. 2. The profile of the diminishing rate of tile amount of urea was quite different from that of the concentration because of the change in the volume of the loop during the observed period. 3. By adding the extract of red pepper, it slowed down the rate of absorption of urea in the intestinal loop, suggesting an increase in the diffusional barrier. 4. Larger dosage of red pepper brought an increase in the secretion of intestinal fluid with concomitant expansion of the luminal volume, and the retardation of the absorption of urea was noticed. This effect was largely dependent on the sensitivity of the individual animal to the red pepper, extract. The amount of urea remained after 10 minutes interval was 55.5% of the initial amount in the experiment without red pepper. On the other hand it was not consistent after administration of red pepper, showing 50.6% and 66.5% of the initial figures by adding 400 mg and 800 mg of red pepper in the test solution, respectively. It was postulated that symptom of diarrhea often encountered by taking a hot (red pepper) food might be attributable to the increase of secretion and the retardation of absorption in the intestinal tract.

• 벤처창업연구
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• 제16권5호
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• pp.75-89
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• 2021

본 연구는 국내 소상공인의 사업성과에 영향을 미치는 요인 중 개인 요인인 창업가 특성과 환경요인인 시장특성이 사업성과에 미치는 영향과 디지털 리터러시의 매개효과를 밝히는 것을 목적으로 한다. 현재 소상공인은 디지털 기술의 확산과 코로나 19의 장기화로 인해 기존의 방식으로 사업을 영위해 나가기 어려운 상황에 직면해 있다. 이들에게 필요한 역량의 하나로 본 연구에서는 디지털 리터러시에 주목하였으며, 디지털 리터러시가 소상공인 개인·시장의 특성, 사업성과와 어떠한 관계에 있는지 살펴보았다. 선행연구에서 소상공인의 사업성과를 설명하는 다양한 요인을 검토하였으며 소상공인의 창업가특성인 혁신성과 자기결정성, 시장특성인 시장의 경쟁정도와 성장성을 독립변수로 도출하고 재무적 성과와 비재무적 성과를 종속변수로 설정하였다. 디지털 리터러시는 독립변수와 종속변수 간의 관계를 매개하는 역할을 할 것으로 보고 가설을 설정하였다. 실증연구를 위해 전국의 소상공인을 대상으로 설문조사를 실시하였고 분석결과를 정리하면 다음과 같다. 소상공인의 혁신성과 자기결정성은 재무적 성과와 비재무적 성과에 정(+)의 유의한 영향을 미치는 것으로 나타났다. 또한 시장의 경쟁정도는 재무적·비재무적 성과에 유의한 영향이 없으며 시장의 성장성은 재무적 성과와 비재무적 성과에 유의한 정(+)의 영향이 있음을 확인하였다. 디지털 리터러시의 매개효과의 경우, 혁신성이 비재무적 성과에 미치는 영향에 대해 부분매개효과가 있으며 시장의 경쟁정도가 재무적 성과와 비재무적 성과에 미치는 영향에 대하여 디지털 리터러시는 완전매개효과가 있음을 확인하였다. 마지막으로 성장성이 비재무적 성과에 미치는 영향에 대하여 디지털 리터러시는 부분매개효과가 있음을 확인하였다. 결과를 살펴보면, 혁신성과 자기결정성에 해당하는 소상공인의 창업가 특성은 직접적으로 사업성과를 높이는 요인으로 작용하며, 시장특성은 간접적으로 디지털 리터러시를 높여서 성과를 올리는 효과가 있음을 알 수 있다. 이상의 연구결과를 토대로 연구의 시사점과 한계점, 그리고 향후 연구방향을 함께 제시하였다.

• 농촌의학ㆍ지역보건
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• 제1권1호
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• pp.5-9
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• 1976

The categories of national health problems may be mainly divided into health promotion, problems of diseases, and population-economic problems which are indirectly related to health. Of them, the problems of diseases will be exclusively dealt with this speech. Rurality and Disease Problems There are many differences between rural and urban areas. In general, indicators of rurality are small size of towns, dispersion of the population, remoteness from urban centers, inadequacy of public transportation, poor communication, inadequate sanitation, poor housing, poverty, little education lack of health personnels and facilities, and in-accessibility to health services. The influence of such conditions creates, directly or indirectly, many problems of diseases in the rural areas. Those art the occurrence of preventable diseases, deterioration and prolongation of illness due to loss of chance to get early treatment, decreased or prolonged labour force loss, unnecessary death, doubling of medical cost, and economic loss. Some Considerations of Innovative Approach The followings art some considerations of innovative approaches to the problems of diseases in the rural Korea. 1. It would be essential goal of the innovative approaches that the damage and economic loss due to diseases will be maintained to minimum level by minimizing the absolute amount of the diseases, and by moderating the fee for medical cares. The goal of the minimization of the disease amount may be achieved by preventive services and early treatment, and the goal of moderating the medical fee may be achieved by lowering the prime cost and by adjusting the medical fees to reasonable level. 2. Community health service or community medicine will be adopted as a innovative means to disease problems. In this case, a community is defined as an unit area where supply and utilization of primary service activities can be accomplished within a day. The essential nature o the community health service should be such activities as health promotion, preventive measures, medical care, and rehabilitation performing efficiently through the organized efforts of the residents in a community. Each service activity should cover all members of the residents in a community in its plan and performance. The cooperation of the community peoples in one of the essential elements for success of the service program, The motivations of their cooperative mood may be activated through several ways: when the participation of the residents in service program of especially the direct participation of organized cooperation of the area leaders art achieved through a means of health education: when the residents get actual experience of having received the benefit of good quality services; and when the health personnels being armed with an idealism that they art working in the areas to help health problems of the residents, maintain good human relationships with them. For the success of a community health service program, a personnel who is in charge of leadership and has an able, a sincere and a steady characters seems to be required in a community. The government should lead and support the community health service programs of the nation under the basis of results appeared in the demonstrative programs so as to be carried out the programs efficiently. Moss of the health problems may be treated properly in the community levels through suitable community health service programs but there might be some problems which art beyond their abilities to be dealt with. To solve such problems each community health service program should be under the referral systems which are connected with health centers, hospitals, and so forth. 3. An approach should be intensively groped to have a physician in each community. The shortage of physicians in rural areas is world-wide problem and so is the Korean situation. In the past the government has initiated a system of area-limited physician, coercion, and a small scale of scholarship program with unsatisfactory results. But there might be ways of achieving the goal by intervice, broadened, and continuous approaches. There will be several ways of approach to motivate the physicians to be settled in a rural community. They are, for examples, to expos the students to the community health service programs during training, to be run community health service programs by every health or medical schools and other main medical facilities, communication activities and advertisement, desire of community peoples to invite a physician, scholarship program, payment of satisfactory level, fulfilment of military obligation in case of a future draft, economic growth and development of rural communities, sufficiency of health and medical facilities, provision of proper medical care system, coercion, and so forth. And, hopefully, more useful reference data on the motivations may be available when a survey be conducted to the physicians who are presently engaging in the rural community levels. 4. In communities where the availability of a physician is difficult, a trial to use physician extenders, under certain conditions, may be considered. The reason is that it would be beneficial for the health of the residents to give them the remedies of primary medical care through the extenders rather than to leave their medical problems out of management. The followings are the conditions to be considered when the physician extenders are used: their positions will be prescribed as a temporary one instead of permanent one so as to allow easy replacement of the position with a physician applicant; the extender will be under periodic direction and supervision of a physician, and also referral channel will be provided: legal constraints will be placed upon the extenders primary care practice, and the physician extenders will used only under the public medical care system. 5. For the balanced health care delivery, a greater investment to the rural areas is needed to compensate weak points of a rurality. The characteristics of a rurality has been already mentioned. The objective of balanced service for rural communities to level up that of urban areas will be hard to achieve without greater efforts and supports. For example, rural communities need mobile powers more than urban areas, communication network is extremely necessary at health delivery facilities in rural areas as well as the need of urban areas, health and medical facilities in rural areas should be provided more substantially than those of urban areas to minimize, in a sense, the amount of patient consultation and request of laboratory specimens through referral system of which procedures are more troublesome in rural areas, and more intensive control measures against communicable diseases are needed in rural areas where greater numbers of cases are occurred under the poor sanitary conditions.