• 한국환경과학회지
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• 제25권8호
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• pp.1097-1105
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• 2016

The present study was performed to investigate the psychological effects of spring flowers blossoms, which is one of the elements influencing to human psychology, in order to provide scientific evidence on the psychological benefits of green plants. A self-reporting survey was conducted by using self reporting questionnaires on the impression (semantic differential method: SD method) and mood states (profile of mood states: POMS) of eighty university students in their twenties. Korean forsythia, Korean rosebay, Japanese apricot, Cherry blossom, and Magnolia were chosen as spring flowers. The results of impression evaluation and mood states changes showed that spring flower blossom had beautiful, soft, warm, moist, familiar and full impressions, and changed our mood positively by reducing depression and anger, or by increasing vigor. In addition, different psychological effects can be differently observed depending on the species; for example, Cherry blossom had a greater effect in changing the impression and feeling than others. The findings would provide support toward the active usage in green space as well as its design maximizing the psychological effects of nature.

• 소성∙가공
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• 제21권8호
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• pp.473-478
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• 2012

The yoke, a component of conventional motor-driven power steering system, often contains welding defects from its manufacturing process. To eliminate these defects, the precision cold forging process has been tried. In this study, the double-action complex forging has been used to manufacture a torsion joint yoke. The backward extrusion proved faster than the forward extrusion in forging of the product. The double-action complex forging process utilized an upper die composed of a punch, a punch guide, a disc spring and a coil spring. The forged material pushes up the punch guide, and then the disc spring and the coil spring balances the backward extrusion force. Consequently, the flow of material was essentially in the forward direction, resulting in a successful forging operation. The forging load of Al 6061-T6 was higher than that of the automotive structural hot rolled plate.

• 한국지하수토양환경학회지:지하수토양환경
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• 제11권4호
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• pp.41-47
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• 2006

온천공에 대한 일일 적정양수량 및 영향평가는 온천법에서 지정된 온천전문기관이 수행하여야 하는 중요한 조사 항목이다. 온천전문조사는 1996년 이전까지 한국지질자원연구원에서 수행하였으나, 2006년 현재에는 8개 온천전문기관이 온천법에 등록되어 있어 일관된 조사가 이루어지지 않고 있는 실정이다. 따라서 이 논문은 온천법 및 온천업무처리지침에서 규정된 사항을 사례적용하는 방법을 통해서 온천전문기관 및 관련 업체에서 온천조사시 동일한 해석을 할 수 있도록 하는 것이 그 목적이다. 적정양수량 산출시 온천공은 양수후 수위회복이 느린 것이 많아 수위회복시간이 고려되었다. 따라서 단계양수시험후 수위회복이 상대적으로 느린 온천공은 적정양수량이 감소하게 된다. 온천공간 영향평가는 2개 이상 온천공사이의 영향관계를 규명하는 것으로서, 신규공에서 양수시험을 실시하고 주위 공들에서의 수위강하를 관측하여 온천공간 영향의 정도를 평가하고 있다.

• 드라이브 ㆍ 컨트롤
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• 제13권3호
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• pp.8-14
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• 2016

This study describes the effect of the critical pressure ratio of a control valve on the performance of an air spring system composed of an air spring, auxiliary chamber, control valve and mass in order to suggest a more efficient design for an air spring system. The critical pressure ratio of the control valve is assumed to have a fixed value, but the critical pressure ratio of the control valve is known to have various values between 0.05 and 0.6, and the effect of the variation of the critical pressure ratio on the performance of the air spring system has not yet been reported. The analysis derives nonlinear and linear governing equations of the air spring system, including the critical pressure ratio of the control valve. This simulation study is presented to show that the impedance and transmissibility characteristics of the air spring system change due to variations in the critical pressure ratio of the control valve as well as its sonic conductance. As a result, the critical pressure ratio of the control valve should be maintained as large as possible to improve the vibration isolation characteristics of the air spring system.

• 한국지하수토양환경학회지:지하수토양환경
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• 제13권1호
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• pp.1-12
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• 2008

이 연구는 한반도 동해안 일대에 분포하고 있는 주요 온천에 대하여 화학성분, 안정동위원소, 삼중수소 그리고 헬륨과 아르곤 같은 영족기체의 동위원소 특성을 분석하여 온천유형별 온천수의 지화학적 특성을 밝히고, 영족기체의 기원을 규명하고자 하였다. 이를 위하여 동해안 일대의 6개 온천지에서 11개의 온천수 시료와 14개의 가스시료를 채취하여 분석하였다. 온천수의 수리화학적 특성을 보면 오색탄산온천수를 제외한 모든 온천수의 pH는 $7.0{\sim}9.1$ 범위의 약알카리성 내지 알카리성을 보이며 오색탄산온천의 pH는 5.7의 약산성의 특성을 보였다. 온천수의 토출온도는 $25.7{\sim}68.3^{\circ}C$ 범위를 보였으며 전기전도도는 $202{\sim}7,130{\mu}S/cm$의 넓은 범위로 해운대와 동래온천은 평균 $3,890{\mu}S/cm$으로 높은 값을 보인다. 온천을 용존성분에 따른 분류하면 오색, 척산, 백암, 덕구온천은 소량의 유황가스 함유한 알카리성의 Na-$HCO_3$형으로 분류되고, 해운대와 동래온천은 높은 TDS(총용존고형물질)의 해수형 Na-Cl형을 보인다. 그리고 오색탄산온천은 약산성으로 탄산을 함유한 Na-$HCO_3$형으로 분류된다. 연구지역 온천수의 ${\delta}^{18}O$와 ${\delta}D$값은 각각 $-7.8{\sim}-11.7%o$과 $-57.3{\sim}86.4%o$의 범위를 보여 온천수가 순환수 기원임을 지시한다. 위도가 높아질수록 낮은 동위원소 조성 값을 보이는 위도효과가 잘 나타난다. 일부 해수형온천수의 삼중수소 함량은 거의 0 TU에 가까운 값을 보여 최소 약 50년 이상 체류한 물임을 알 수 있다. 오색탄산온천수를 제외한 온천수의 $^3He/^4He$ 동위원소비는 $0.1{\times}10^{-6}{\sim}1.1{\times}10^{-6}$ 범위를 보여, 대기-지각 혼합선보다 상위에 분포한다. 이는 온천수내 He 가스가 대부분 대기와 지각기원이며, 일부는 맨틀기원의 He 가스가 부분적으로 존재한다는 것을 의미한다. 판 경계부에 위치한 일본의 온천수내 He가스는 대부분이 맨틀기원으로 알려져 있어 판 경계부에서 떨어진 우리나라의 경우와 뚜렷한 차이를 보인다. 그러나, 오색탄산온천에서는 대기기원 He 동위원소비보다 2.4배 높은 값인 $3.3{\times}10^{-6}$을 보여주어 지하 심부의 맨틀기원의 가스가 지각상부 대수층까지 공급된 것으로 해석된다. 온천수의 $^{40}Ar/^{36}Ar$ 비는 대기기원의 값과 유사한 범위를 보인다.

• 원자력산업
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• 제11권10호통권104호
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• pp.66-71
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• 1991

• 한국농림기상학회지
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• 제17권4호
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• pp.275-280
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• 2015

미래 기후조건에서 농업부문 가뭄양상을 전망하기 위해 우리나라 농업의 중심지인 전주지역을 대상으로 1951-2100 기간의 기후변화시나리오(RCP8.5) 일자료를 이용하여 토양의 물수지에 근거한 농업가뭄지수를 계산하였다. 계산결과는 과거(1951-1980), 현재(1981-2010), 그리고 3개의 미래 기후학적 평년기간(2011-2040, 2041-2070, 2071-2100)으로 분류하여 분석하였다. 그 결과 과거부터 현재까지 계절적으로 가장 부족한 이른봄의 토양수분은 점차 개선되어 금세기말이면 수분부족현상이 해소될 것으로 전망되며, 봄철 가뭄발생빈도 역시 지금보다 줄어들어 이른봄에는 가뭄이 거의 나타나지 않을 것이다. 반면 여름작물 생육기간에는 토양수분상태가 악화되며 가뭄발생빈도가 대체로 증가할 것으로 전망되었다.

• 농업과학연구
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• 제44권3호
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• pp.400-408
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• 2017

This experiment was conducted to estimate the livestock carrying capacity per unit area of Hanwoo heifer with determine the quality of the forage by evaluating the productivity and nutritive value of spring seeding oats (Avena sative L.) according to different seeding and harvesting timings. Dry matter yields were the highest at 13.62 tons per ha when oat was seeded on March 15 and harvested on June 8 (p < 0.05), while the lowest yield of 6.29 tons per ha was obtained when seeded on February 25 and harvested on May 19 (p < 0.05). The highest crude protein yield of 1.27 tons per ha (p < 0.05) was obtained when seeded on March 5 and harvested on June 8. The total digestible nutrient yield was the highest at 7.38 tons per ha when harvested on June 8, the last harvest of the experiment (p < 0.05). In the northern part of Gyeongbuk province, spring seeding oats at the beginning of March, rather than in the middle of March, showed good annual livestock carrying capacity per unit area. According to harvest timing, the plot harvested on June 8 showed the highest livestock carrying capacity with an average of 6.53 heads (p < 0.05). In conclusion, in the northern part of Gyeongbuk province in spring, it is better to seed oat early in March and to harvest early in June to increase the livestock breeding capacity, considering dry matter productivity and feed value.

• 한국동물위생학회지
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• 제20권3호
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• pp.261-279
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• 1997

The study for a effect of monitoring on bovine mastitis was conduced for improvement of raw milk from Jan. to Dec. in 1996. Sampling the milk of 367 cows(1, 406 quarters) from 5 herds in Inchon and were carried out California mastitis test(CMT), somatic cell count(SCC), isolation of pathogens and antibiotic sensitivity tests. The results were summarized as follows, 1. The number of bovine mastitis was 177 cows(48.2%) and 371 quarters(26.4%) : clinical mastitis : 25 cows(6.8%), 32 quarters(2.3%) and subclinicsl mastitis : 152 cows(41.4% ), 339 quarters(24.1%). Incidence rate of mastitis by season were Summer 52.0%, Fall and Winter 48% and Spring 41%. Incidence rate of mastitis by quarters were Summer 30%, Fall 28%, Winter 25% and Spring 21%, respectively. 2. In the distribution of CMT degree by quarter, CMT positive(CMT$\pm$) of 1, 406 quarters milk were 50.1% (704 quarters). The ratio of CMT positivity by quarter were left front quarter 55.8%, right front quarter 48.9%, right hind quarter 48.6% and left hind quarter 47% The ratio of CMT positivity by season were Summer 54.1%, Fall 49.7%, Spring 48.5% and Winter 48% 3. The highest mean SCC by season among 5 herds was "A" herd. Mean SCC (cell/ml) of A herd were Summer 2, 032, 000cells/ml, Fall 1, 109, 000cells/ml, Winter 782, 000cells/ml and Spring 577, 000cells/ml. The lowest mean SCC by season among 5 herds was "E" herds. Mean SCC of E herd were Summer 1, 064, 000cells/ml, Spring 795, 000cells/m1, Fall 429, 000cells/ml and Winter 400, 000cells/ml. Mean SCC of the other herds by season were little difference. 4. The milk samples of "A" herd were collected from 10 cows. In 3 seasons, mean SCC of No. 2 and 3 cows were than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 6, 7 and 8 cows were than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows by season were distributed Summer 4 cows, Winter 3 cows, Spring and Fall 1 cow respectively. The milk samples of "B" herd were collected from 14 cows. In 3 seasons, mean SCC of No. 1 cow was more than 1, 000, 000cells/ml. In 2 seasons, mean SCC of No. 5, 9 and 14 cows were more than 1, 000, 000cells/ml. In 1 season, No. 3, 6 and 7 cows were more than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows by season were distributed Fall and Winter 4 cows respectively, Summer 3 cows and Spring 1 cow. The milk samples of "C" herd were collected from 18 cows. In 2 seasons, mean SCC of No. 16 cow was more than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 1, 2, 6, 7, 13, 15 and 18 cows were more than 1, 000, 000cells/ml respectively. The more than mean SCC 1, 000, 000cells/ml of cows by season were distributed Summer 5 cows, Fall 3 cows, Spring 2 cows and Winter 1 COW. The milk sampes of "D" herd were collected 24 cows. In 3 season, mean SCC of No. 14 cow was more than 1, 000, 000cells/ml. In 2 seasons, mean SCC of No. 14 and 18 cows were more than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 1, 2, 3, 8, 12, 17, 19, 20 and 21 cows were more than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows were distributed Fall 15 cows, Spring and Winter 4 cows respectively and Summer 3 cows. The milk samples of "E" herd were collected from 27 cows. In 2 seasons, mean SCC of No. 6, 7 and 21 cows were more than 1, 000, 000cells/ml. In 1 season, mean SCC of No. 2, 4, 7, 11, 14, 16 and 23 cows were more than 1, 000, 000cells/ml. The more than mean SCC 1, 000, 000cells/ml of cows were distributed Spring and Fall 5 cows respectively, Summer and Winter 2 cows, respectively. 5. The rate of isolated pathogenic microorganisms from bovine mastitis were summarized as follows : Staphylococcus sp 168 strains(45.8%), Streptococcus sp 82 strains(22.3%), Gram(-) sp 45 strains(12.3%), Gram(＋) sp 51 strains and the other sp 21 strains(5.7%). 6. The highest of antibiotic sensitivity test of each microorganism was summarized as follows : Staphyolcoccus sp - cephalosporin 76%, gentamicin 55%, Streptococcus sp - ampicillin 61%, cephalosporin 63%, Gram(-) sp - gentamicin 58%, Gram(＋) sp - cephalosporin 63%, The other sp - cephalosporin 90%. Microorganisms showed the highest sensitivity(68%) to cephalospsorin. Microorganisms showed the highest sensitivity(68%) to cephalospsorin.

• 한국분무공학회지
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• 제6권1호
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• pp.1-8
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• 2001

Fuel injection system is very important in diesel combustion. Recently electronic control of fuel injection system and common rail systems are introduced to reduce the emission and to increase the energy efficiency from diesel engine by control of the injection timing and duration. In this study, evaluation possibility of the system for electronic control by spool valve, one of the accumulator type injection systems with spool valve using solenoid was composed and the operating characteristics were investigated to evaluate the effects of spring coefficient, initial spring force, solenoid driving time, fuel supply pressure on the injection timing and duration. We could confirm the capability that diesel injection was electronically controlled by spool valve.