• 제목/요약/키워드: good balance system

검색결과 196건 처리시간 0.028초

콘빔 전산화단층촬영(CBCT) 시스템에서 기계적 오류에 관한 연구 (A Study on Mechanical Errors in Cone Beam Computed Tomography(CBCT) System)

  • 이이성;유은정;김승근;최경식;이정우;서태석;김정구
    • 대한방사선기술학회지:방사선기술과학
    • /
    • 제36권2호
    • /
    • pp.123-129
    • /
    • 2013
  • 본 연구는 선형가속기의 회전불균형의 영향으로 발생 되는 CBCT 영상의 setup 오차 변화를 분석하여, 회전불균형에 대한 정도관리의 필요성을 연구 하였다. CBCT 시스템의 3차원 체적영상모드를 이용하여 $360^{\circ}$ 회전과 $180^{\circ}$ 회전으로 Catphan503 팬텀과 균질 팬텀의 3차원 영상을 획득하였고, setup 오차를 측정하기 위해 나선형 CT의 기준영상과 함께 비교 분석 하였다. 표준 정도관리의 절차를 시행하여 정상적인 상태를 확인하고, 임의적으로 갠트리의 회전균형을 조절한 후, 균형상태와 불균형상태의 각각 CBCT 영상에 대하여 X, Y, Z, Roll, Pitch, and Yaw의 6차원적 관점에서 setup 오차를 측정하고 분석하였다. Setup 오차의 변화율은 갠트리 회전균형의 조정 전 후를 확인한 결과, 직교 좌표계는 $360^{\circ}$의 회전에서 X축 방향으로 0.6 mm, Y축 방향으로 0.5 mm, Z축 방향으로 0.5 mm의 최대 변화율을 보였다. $180^{\circ}$의 회전은 X축 방향으로 0.9 mm, Y축 방향은 0.2 mm, Z축 방향은 0.3 mm의 최대 변화율을 보였다. 또한 회전 변환계는 회전 불균형이 커질수록 평균적인 값의 차이가 점점 증가하였고, 최대값은 $1.1^{\circ}$를 나타내었다. 영상의 분해능은 균형 조정 전 후 영상분석 툴에서 2 lp/cm 차이를 나타내었다. CBCT 시스템의 정도관리는 기준 권고안을 만족하였다. 갠트리의 회전 불균형이 클 때, setup 오차의 직교 좌표계의 변화는 크지 않았으나, 회전 변환계의 변화율은 기준 권고 값인 $1^{\circ}$에 해당하는 값과 초과하는 $1.1^{\circ}$를 나타내었다. 이는 갠트리의 불균형이 setup 오차에 영향을 미치는 것을 알 수 있었으며, 또한 회전 변환계의 setup 오차에 대한 6차원적인 보정이 더욱 요구됨을 알 수 있다. 그러므로 정확하고 정교한 영상유도 방사선치료를 수행하기 위해서는 갠트리의 균형도를 확인해야 하며, 정도관리 항목으로 추가되어야 한다고 사료되어진다.

여헌(旅軒) 장현광(張顯光)의 교육관 탐구 - 성리학적 본질의 심화 - (Quest for Yeoheon Jang Hyeon-gwang's View on Education - Deepening of the intrinsic nature in accordance with the Neo-Confucianistic thought)

  • 신창호
    • 동양고전연구
    • /
    • 제33호
    • /
    • pp.31-56
    • /
    • 2008
  • 여헌 장현광은 조선시대 여타의 유학자에 비해 철저하게 성리학의 본질을 충실하게 탐구하고, 심도 있게 학설을 확장시킨 학자이다. 여헌은 성리학적 교육의 기본 체계인 "대학"과 "중용"에 의거하여 자신의 학설을 강화한다. 이러한 사유의 전개에 근거하여 여헌의 교육사상은 세 측면에서 조명해 볼 수 있다. 첫째, 여헌은 교육의 기준으로서 성인군주론(聖人君主論)을 심화한다. 그것은 본질적으로 존천리알인욕(存天理?人欲)을 추구하며, 도덕적 각성과 덕치주의를 강조한다. 둘째, 여헌은 교육의 양식으로서 성경(誠敬)의 공부론을 강조한다. 여헌은 마음에 성(誠)과 경(敬)을 세울 것을 강조하고, 두 가지의 차별성을 인정하면서도 동일한 맥락에서 이해한다. 셋째, 여헌은 교육의 방법으로서 분합(分合)의 조화를 주창한다. 여헌은 그의 독특한 리기경위설(理氣經緯說)을 통해, 역(易)의 논리에 따라 어느 한쪽으로 치우치거나 지나치지 않는 중용의 관점을 유지한다. 이러한 여헌의 교육적 사유는 현대 교육적 의미에서 볼 때, 교육의 표준을 도덕의 확립에 두고, 교육의 양식과 방법에서 중용적 통찰을 고려하는 아이디어를 제공한다. 요컨대, 여헌의 교육사상은 일관성을 지닌 전통 성리학의 교육적 지혜를 담고 있는데, 현대 교육의 기준 혼란, 내용의 비체계화, 방법적 치우침에 대한 균형 감각의 중요성을 재검토하는 데 주요한 시사점을 준다.

고객만족이 기업의 신용평가에 미치는 영향 (The Effect of Customer Satisfaction on Corporate Credit Ratings)

  • 전인수;전명훈;유정수
    • Asia Marketing Journal
    • /
    • 제14권1호
    • /
    • pp.1-24
    • /
    • 2012
  • 본 연구는 고객만족과 기업가치 성과간의 관계를 분석하는 것이 목적이다. 기업가치성과는 주가와 신용등급으로 나눌 수 있는데, 전자는 기업의 시장가치이고 후자는 자금조달비용이라 구분하여 사용되고 있다. 고객만족과 주가와의 관계는 비교적 오래전부터 연구되어 왔으나 신용등급과의 관계는 최근 들어 연구되기 시작하였다. 대표적으로 Anderson and Mansi(2009)의 연구에서는 양자가 긍정적으로 관련된 것으로 밝혀졌으나, 윤상운(2010)이 국내자료를 사용한 연구에서는 그 관계가 입증되지 못하였다. 일치하지 않는 두 연구의 결과에서 아이디어를 얻어 본 연구에서는 고객만족이 신용등급에 긍정적 영향을 미치는 것으로 보고 이를 검증하였다. 두 연구에서 사용한 모델을 참고로 하였고 특히 우리나라 실정에서는 정부지원이 중요한 변수임을 감안하여 이를 포함한 연구모형을 설정하여 검증한 결과 긍정적 관련성이 있는 것으로 나타났다. 추가분석에서 자산규모가 큰 기업보다 작은 기업에서, 제조업보다 서비스업에서 고객만족이 신용등급에 더 유의한 긍정적 영향을 미치는 것으로 나타났다.

  • PDF

새만금간척지 사료작물 재배시 질소증비 효과 (Effects of Nitrogen Fertilization Increment on Forage Crops Cultivation in Saemangum Reclaimed Land)

  • 양창휴;김선;이장희;백남현;김택겸;최원영;정재혁;이상복;이경보
    • 한국토양비료학회지
    • /
    • 제45권2호
    • /
    • pp.235-240
    • /
    • 2012
  • 본 연구는 새만금간척지 (광활지구) 신간척지에서 조사료의 안정생산을 위하여 사료작물 재배시 질소 증비효과, 생육 및 수량성을 검토코자 2008년 10월부터 2009년 10월까지 수행하였다. 동계 사료작물로 청보리 (영양), 하계 사료작물로 옥수수(광평옥), 수수${\times}$수단그라스 (G7)를 재배하여 토양화학성, 양분흡수량, 생육 및 수량성을 검토하였다. 공시토양은 유기물, 유효인산 및 치환성칼슘 함량이 매우 적었고 치환성 마그네슘 나트륨 함량이 많은 강알칼리성 염류토양 이었다. 재배기간 동안 토양염농도 변화는 0.1%이하를 나타냈고 염피해는 없었다. 동 하계작물 경엽 및 곡실 중 무기양분 함량은 질소증비로 증가하는 경향을 나타냈으며 옥수수에서 높았다. 특히 청보리 무기성분 중 T-N, CaO, MgO 함량은 일반농경지에서 재배된 것에 비하여 2배정도 낮은 반면에 $P_2O_5$, $Na_2O$ 함량은 2배정도 높았다. 청보리는 질소증비로 초장이 길고 경수 확보가 많았으며 $10,740{\sim}13,170kg\;ha^{-1}$ 건물수량을 나타냈다. 또한 하계작물은 질소증비로 초장이 길고 경직경이 굵었으며 옥수수 $13,120{\sim}15,050kg\;ha^{-1}$, 수수${\times}$수단그라스 $14,400{\sim}19,440kg\;ha^{-1}$ 건물수량을 나타냈다. 결론적으로 간척지토양은 생산성을 향상시키고 양분균형을 이루기 위하여 종합적인 토양관리가 선행되어야 할 것으로 생각된다.

국경을 넘는 해양환경오염에 대한 국가책임과 적용의 한계 -중국의 산샤댐 건설로 인한 동중국해 해양환경 영향을 중심으로- (Limitations of National Responsibility and its Application on Marine Environmental Pollution beyond Borders -Focused on the Effects of China's Three Gorges Dam on the Marine Environment in the East China Sea-)

  • 양희철
    • Ocean and Polar Research
    • /
    • 제37권4호
    • /
    • pp.341-356
    • /
    • 2015
  • A nation has a sovereign right to develop and use its natural resources according to its policies with regard to development and the relevant environment. A nation also has an obligation not to harm other countries or damage environments of neighboring countries as consequences of such actions of developments or use of natural resources. However, international precedents induce a nation to take additional actions not to cause more damages from the specific acts causing environmental damages beyond national borders, when such acts have economic and social importance. That is to say that there is a tendency to resolve such issues in a way to promote the balance between the mutual interests by allowing such actions to continue. A solution to China's Three Gorges Dam dilemma based on a soft law approach is more credible than relying on a good faith approach of national responsibilities and international legal proceedings since the construction and operation of the dam falls within the category of exercising national sovereign rights. If a large scale construction project such as the Three Gorges Dam or operation of a nuclear power plant causes or may cause environmental damage beyond the border of a nation engaged in such an undertaking, countries affected by this undertaking should jointly monitor the environmental effects in a spirit of cooperation rather than trying to stop the construction and should seek cooperative solutions of mutual understanding to establish measures to prevent further damages. If China's Three Gorges Dam construction and operation cause or contain the possibility of causing serious damages to marine environment, China cannot set aside its national responsibility to meet international obligations if China is aware of or knows about the damage that has occurred or may occur but fail to prevent, minimize, reverse or eliminate additional chances of such damages, or fails to put in place measures in order to prevent the recurrence of such damages. However, Korea must be able to prove a causal relationship between the relevant actions and resulting damages if it is to raise objections to the construction or request certain damage-prevention actions against crucial adverse effects on the marine environment out of respect for China's right to develop resources and acts of use thereof. Therefore, it is essential to cumulate continuous monitoring and evaluations information pertaining to marine environmental changes and impacts or responses of affected waters as well as acquisition of scientific baseline data with observed changes in such baseline. As China has adopted a somewhat nonchalant attitude toward taking adequate actions to protect against marine pollution risks or adverse effects caused by the construction and operation of China's Three Gorges Dam, there is a need to persuade China to adopt a more active stance and become involved in the monitoring and co-investigation of the Yellow Sea in order to protect the marine environment. Moreover, there is a need to build a regular environmental monitoring system that includes the evaluation of environmental effects beyond borders. The Espoo Convention can serve as a mechanism to ease potential conflicts of national interest in the Northeast Asian waters where political and historical sensitivities are acute. Especially, the recent diplomatic policy advanced by Korea and China can be implemented as an important example of gentle cooperation as the policy tool of choice is based on regional cooperation or cooperation between different regions.

한국의 지역개발과 댐건설 (Regional Development And Dam Construction in Korea)

  • 안경모
    • 물과 미래
    • /
    • 제9권1호
    • /
    • pp.38-42
    • /
    • 1976
  • Because of differences in thoughts and ideology, our country, Korea has been deprived of national unity for some thirty years of time and tide. To achieve peaceful unification, the cultivation of national strength is of paramount importance. This national strength is also essential if Korea is to take rightful place in the international societies and to have the confidence of these societies. However, national strength can never be achieved in a short time. The fundamental elements in economic development that are directly conducive to the cultivation of national strength can be said to lie in -a stable political system, -exertion of powerful leadership, -cultivation of a spirit of diligence, self-help and cooperation, -modernization of human brain power, and -establishment of a scientific and well planned economic policy and strong enforcement of this policy. Our country, Korea, has attained brilliant economic development in the past 15 years under the strong leadership of president Park Chung Hee. However, there are still many problems to be solved. A few of them are: -housing and home problems, -increasing demand for employment, -increasing demand for staple food and -the need to improve international balance of payment. Solution of the above mentioned problems requires step by step scientific development of each sector and region of our contry. As a spearhead project in regional development, the Saemaul Campaign or new village movement can be cited. The campaign is now spreading throughout the country like a grass fire. However, such campaigns need considerable encouragement and support and the means for the desired development must be provided if the regional and sectoral development program is to sucdceed. The construction of large multipurpose dams in major river basin plays significant role in all aspects of national, regional and sectoral development. It ensures that the water resource, for which there is no substitute, is retained and utilized for irrigation of agricultural areas, production of power for industry, provision of water for domestic and industrial uses and control of river water. Water is the very essence of life and we must conserve and utilize what we have for the betterment of our peoples and their heir. The regional and social impact of construction of a large dam is enormous. It is intended to, and does, dras tically improve the "without-project" socio-economic conditions. A good example of this is the Soyanggang multipurpose dam. This project will significantly contribute to our national strength by utilizing the stored water for the benefit of human life and relief of flood and drought damages. Annual average precipitation in Korea is 1160mm, a comparatively abundant amount. The catchment areas of the Han River, Keum River, and Youngsan River are $62,755\textrm{km}^2$, accounting for 64% of the national total. Approximately 62% of the national population inhabits in this area, and 67% of the national gross product comes from the area. The annual population growth rate of the country is currently estimated at 1.7%, and every year the population growth in urban area increases at a rising rate. The population of Seoul, Pusan, and Taegu, the three major cities in Korea, is equal to one third of our national total. According to the census conducted on October 1, 1975, the population in the urban areas has increased by 384,000, whereas that in rural areas has decreased by 59,000,000 in the past five years. The composition of population between urban and rural areas varied from 41%~59% in 1959 to 48%~52% in 1975. To mitigate this treand towards concentration of population in urban areas, employment opportunities must be provided in regional and rural areas. However, heavy and chemical industries, which mitigate production and employment problems at the same time, must have abundant water and energy. Also increase in staple food production cannot be attained without water. At this point in time, when water demand is rapidly growing, it is essential for the country to provide as much a reservoir capacity as possible to capture the monsoon rainfall, which concentarated in the rainy seaon from June to Septesmber, and conserve the water for year round use. The floods, which at one time we called "the devil" have now become a source of immense benefit to Korea. Let me explain the topographic condition in Korea. In northern and eastern areas we have high mountains and rugged country. Our rivers originate in these mountains and flow in a general southerly or westerly direction throught ancient plains. These plains were formed by progressive deposition of sediments from the mountains and provide our country with large areas of fertile land, emminently suited to settlement and irrigated agricultural development. It is, therefore, quite natural that these areas should become the polar point for our regional development program. Hower, we are fortunate in that we have an additional area or areas, which can be used for agricultural production and settlement of our peoples, particularly those peoples who may be displaced by the formation of our reservoirs. I am speaking of the tidelands along the western and southern coasts. The other day the Ministry of Agriculture and Fishery informed the public of a tideland reclamation of which 400,000 hectares will be used for growing rice as part of our national food self-sufficiency programme. Now, again, we arrive at the need for water, as without it we cannot realize this ambitious programme. And again we need those dams to provide it. As I mentioned before, dams not only provide us with essential water for agriculture, domestic and industrial use, but provide us with electrical energy, as it is generally extremely economical to use the water being release for the former purposes to drive turbines and generators. At the present time we have 13 hydro-electric power plants with an installed capacity of 711,000 kilowatts equal to 16% of our national total. There are about 110 potential dams ites in the country, which could yield about 2,300,000 kilowatts of hydro-electric power. There are about 54 sites suitable for pumped storage which could produce a further 38,600,000 kilowatts of power. All available if we carefully develop our water resources. To summarize, water resource development is essential to the regional development program and the welfare of our people, it must proceed hand-in-hand with other aspects of regional development such as land impovement, high way extension, development of our forests, erosion control, and develop ment of heavy and chemical industries. Through the successful implementation of such an integrated regional development program, we can look forward to a period of national strength, and due recognition of our country by the worlds societies.

  • PDF