• 제목/요약/키워드: minimal condition

검색결과 369건 처리시간 0.026초

인공물과 책임귀속 조건 (Artifacts and Conditions for Attribution of Responsibility)

  • 김남호
    • 철학연구
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    • 제147권
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    • pp.59-76
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    • 2018
  • 어떤 존재 x를 도덕적 행위자로 만들어주는 조건은 무엇인가? 인공물도 도덕적 행위자일 수 있는가? 도덕적 행위자는 옳고 그름을 판단할 수 있는 이성적 존재로 간주된다. 본 논문에서는 우선 이성적 존재에 대한 조건에 대한 데이빗슨의 입장을 비판적으로 분석하면서, 명제적 태도(propositional attitude)를 가지는 믿음과 그 배경으로서의 믿음들의 연결망은 이성적 존재의 필요조건이 될 수 없음이 논증된다. 그런 뒤에 도덕적 행위자의 조건에 대한 프로케소바(Eva $Proke{\check{s}}ov{\acute{a}}$)의 입장에 대한 분석을 통해서 프로케소바가 제시한 조건들은 단지 피상적인 요소들의 병렬적 나열에 불과함이 밝혀진다. 본 논문에서 도덕적 행위자는 이성적 행위자를 포함하며, 강한 일인칭 시점이 이성적 행위자와 도덕적 행위자의 필요충분조건임이 논증된다. 결론적으로 도덕적 행위자로서의 가능성을 완강하게 부정하는 강한 회의론 대신에 도덕적 행위자의 조건을 제시함으로써 인공물의 행위자 가능성에 잠정적 한계를 설정해주는 온건한 회의론의 밑그림이 제시될 것이다.

도시철도 운영환경에서 파상마모에 의한 레일체결장치 클립의 진동 특성 (Rail Corrugation Effects on the Dynamic Behavior of Clips of Rail Fastening System in Operation Environment of Urban Railway)

  • 김만철;유원희;심형보
    • 한국철도학회논문집
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    • 제19권4호
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    • pp.489-497
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    • 2016
  • 레일체결장치는 레일을 침목 등에 결속시켜 정해진 궤간의 유지와 열차 하중을 하부의 침목 및 도상 등에 전달하는 역할을 수행하는 주요 궤도 구성품이다. 본 논문에서는 도시철도 운영환경에서 파상마모에 대한 레일체결장치 클립의 진동 특성 분석을 위해서 조립상태에서 레일체결장치 클립의 모달테스트를 수행하여 고유진동수를 측정하였으며, 이를 파상마모에 의한 통과주파수와의 비교를 통해 공진 영향을 검토하였다. 또한 열차 주행시 파상마모에 따른 레일 및 레일체결장치 클립의 가속도와 레일체결장치 클립의 변형률을 계측하였다. 분석결과 레일 및 레일체결장치 클립의 가속도는 파상마모와 매우 밀접한 관계를 가지고 있으나, 레일체결장치 클립의 변형률과의 관계는 미비한 것으로 나타났다.

스월 분사와 삽입연료에 의한 하이브리드 로켓 연소의 저주파수 연소불안정 조절 (Controlling Low Frequency Instability in Hybrid Rocket Combustion With Swirl Injection and Fuel Insert)

  • 현원정;이창진
    • 한국항공우주학회지
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    • 제49권2호
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    • pp.139-146
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    • 2021
  • 하이브리드 로켓 연소에서 산화제 스월 분사는 회전방향 속도성분이 경계층 유동에 영향을 미쳐 연소안정화에 기여한다. 그러나 스월 강도가 증가할수록 연소성능을 과도하게 변화시키는 문제점이 나타난다. 따라서 참고문헌[7]의 삽입연료와 함께 사용하여 연소성능 변화를 최소화 하면서 연소불안정 억제를 시도하였다. 이를 위해, 일련의 실험을 계획하여 스월 강도와 삽입연료 위치를 변화하며 연소불안정의 발생과 연소성능 변화를 관찰하였다. 실험결과, 스월 각 6°, 삽입연료 위치 310 mm 조합에서 연소불안정이 억제되었으며 연소압력, O/F 비 그리고 연료 후퇴율 등의 변화가 최소인 것으로 확인하였다. 또한 고주파수 대역의 압력진동(p')와 열방출진동(q')의 위상차가 π/2로 음의 결합을 형성하도록 연소조건을 유지하는 것이 저주파수 연소불안정 발생을 억제하는 필요충분조건임을 재확인하였다.

The alternative Method to Finish Modular Exponentiation and Point Multiplication Processes

  • Somsuk, Kritsanapong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권7호
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    • pp.2610-2630
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    • 2021
  • The aim of this paper is to propose the alternative algorithm to finish the process in public key cryptography. In general, the proposed method can be selected to finish both of modular exponentiation and point multiplication. Although this method is not the best method in all cases, it may be the most efficient method when the condition responds well to this approach. Assuming that the binary system of the exponent or the multiplier is considered and it is divided into groups, the binary system is in excellent condition when the number of groups is small. Each group is generated from a number of 0 that is adjacent to each other. The main idea behind the proposed method is to convert the exponent or the multiplier as the subtraction between two integers. For these integers, it is impossible that the bit which is equal to 1 will be assigned in the same position. The experiment is split into two sections. The first section is an experiment to examine the modular exponentiation. The results demonstrate that the cost of completing the modular multiplication is decreased if the number of groups is very small. In tables 7 - 9, four modular multiplications are required when there is one group, although number of bits which are equal to 0 in each table is different. The second component is the experiment to examine the point multiplication process in Elliptic Curves Cryptography. The findings demonstrate that if the number of groups is small, the costs to compute point additions are low. In tables 10 - 12, assigning one group is appeared, number of point addition is one when the multiplier of a point is an even number. However, three-point additions are required when the multiplier is an odd number. As a result, the proposed method is an alternative way that should be used when the number of groups is minimal in order to save the costs.

Choice Stepping Reaction Time under Unstable Conditions in Healthy Young and Older Adults: A Reliability and Comparison Study

  • Lim, Ji Young;Lee, Seong Joo;Park, Dae-Sung
    • The Journal of Korean Physical Therapy
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    • 제33권6호
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    • pp.265-271
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    • 2021
  • Purpose: We aimed to analyze the reliability of the test for choice stepping reaction time (CSRT) under an unstable surface and determine whether there were differences in CSRT between support surface conditions (stable vs. unstable conditions) and between age groups (young adults vs. community-dwelling older adults). Methods: Twenty healthy community-dwelling older adults and twenty young adults performed the stepping task under an unstable condition over two visits. The mean of the two trials measured for each visit was used for the analysis. The test-retest reliability was analyzed using intra-class correlation coefficient (ICC) with a 95% confidence interval, standard error of measurement (SEM), and minimal detectable change (MDC). Differences in CSRT between support surface conditions and age groups were analyzed using the independent t-test with Bonferroni correction. Results: Excellent consistency was observed for ICC >0.90 in both groups. Moreover, the SEM and MDC values of the CSRT in older and young adults were 0.03 and 0.09 and 0.01 and 0.04, respectively. There was a significant difference in the CSRT between the age groups under stable (p<0.001) and unstable conditions (p<0.001). Conclusion: The findings demonstrated that the test for CSRT under an unstable condition had reliable results in both groups. Although older adults demonstrated longer reaction times than younger adults in all surface conditions, increasing the balance control demand by implementing a choice stepping task concomitant with a balance task had no influence on the reaction time in both age groups.

Optimal Decomposition of Convex Structuring Elements on a Hexagonal Grid

  • Ohn, Syng-Yup
    • The Journal of the Acoustical Society of Korea
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    • 제18권3E호
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    • pp.37-43
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    • 1999
  • In this paper, we present a new technique for the optimal local decomposition of convex structuring elements on a hexagonal grid, which are used as templates for morphological image processing. Each basis structuring element in a local decomposition is a local convex structuring element, which can be contained in hexagonal window centered at the origin. Generally, local decomposition of a structuring element results in great savings in the processing time for computing morphological operations. First, we define a convex structuring element on a hexagonal grid and formulate the necessary and sufficient conditions to decompose a convex structuring element into the set of basis convex structuring elements. Further, a cost function was defined to represent the amount of computation or execution time required for performing dilations on different computing environments and by different implementation methods. Then the decomposition condition and the cost function are applied to find the optimal local decomposition of convex structuring elements, which guarantees the minimal amount of computation for morphological operation. Simulation shows that optimal local decomposition results in great reduction in the amount of computation for morphological operations. Our technique is general and flexible since different cost functions could be used to achieve optimal local decomposition for different computing environments and implementation methods.

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구치 편측확장을 위한 Precision Lingual Arch 적용시 응력분포에 관한 유한요소법적 연구 (AN ANALYSIS OF STRESS DISTRIBUTION IN THE CASE OF UNILATERAL MOLAR EXPANSION WITH PRECISION LINGUAL ARCH BY FINITE ELEMENT METHOD)

  • 구본찬;손병화
    • 대한치과교정학회지
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    • 제24권3호
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    • pp.721-733
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    • 1994
  • Orthodontic tooth movement is closely related to the stress on the periodontal tissue. In this research the finite element method was used to observe the stress distribution and to find the best condition for effective tooth movement in the case of unilateral molar expansion. The author constructed the model of lower dental arch of average Korean adult and used $.032'\times.032'\times60mm$ TMA wire. The wire was deflected in the horizontal and vertical direction to give the 16 conditions. The following results were obtained ; 1. When the moment and force were controlled properly the movement of anchor tooth was minimized and the movement of moving tooth was maximized. 2. As the initial horizontal deflection increased the buccal displacement of both teeth was also increased. As the initial horizontal deflection increased the lingual movement of anchor tooth and the buccal movement of moving tooth increased. 3. When the initial horizontal and vertical deflection rate was 1.5 the effective movement of moving tooth was observed with minimal displacement of anchor tooth.

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Two Pediatric Patients with Herbal Medicine-Induced Nephrotic Syndrome

  • Yang, Sohyoung;Oh, Arum;Ha, Tae-Sun
    • Childhood Kidney Diseases
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    • 제19권2호
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    • pp.171-175
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    • 2015
  • Nephrotic syndrome (NS) is a common chronic disease in children; in 90 percent of cases, the condition is primary (idiopathic). Toxic nephropathy can be induced by herbal medicines, and is mainly manifested as tubulointerstitial nephritis and rarely, as glomerulopathy. Here in, we describe two cases of steroid-sensitive NS, which developed after the patients received herbal medicines. A 5-year-old boy and an 8-year-old girl were separately admitted within a short time period with acute onset of generalized edema, proteinuria, hypoalbuminemia, and hypercholesterolemia. Each patient had previously taken herbal medicine, which had been prescribed by different oriental medical clinics for different conditions. The patients were diagnosed with herbal medicine-induced NS and were treated empirically by a standard steroid therapy, with subsequent resolution of their NS. One patient relapsed, but her NS again responded to steroid therapy. We described two unusual cases of prototypical pediatric, steroid-sensitive NS, which was presumed to be minimal-change disease that developed after the administration of herbal medicines. We also reviewed the literature.

프라이머 중합체를 이용한 원위치 중합효소 연쇄반응 In situ PCR 방법의 개발 (Development of In situ PCR Method Using Primer Polymers)

  • 장진수;이재영
    • 미생물학회지
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    • 제40권2호
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    • pp.167-171
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    • 2004
  • 효과적인 원위치 중합효소 연쇄반응 (In situ PCR)을 위해서는 증폭된 PCR 산물의 세포외 유출을 감소시켜야 한다. 이를 위한 한 방법으로 거대분자 PCR 산물을 합성시키기 위한 5'쪽에 서로 상보적인 꼬리서열을 가진 프라이머(꼬리 프라이머; tailed primer)가 사용되었으나 많은 PCR 횟수로 인해 시간의 낭비와 세포조직의 형태보존성이 저하되는 문제가 발생하였다. 따라서 PCR 조건을 가능한 최적화시키고, 최소의 PCR 횟수로써 세포외 유출을 막을 수 없는 방법이 필요하게 되었다. 이러한 방법의 일환으로 꼬리 프라이머를 이용하여 PCR 튜브 속에서 목표 핵산없이 프라이머 중합체(primer polymers)의 형성을 유도하였고, 이를 유리 슬라이드위에 고정시킨 Molt/LAV 세포들에 처리하여 20 회의 짧은 시간에서도 적절한 탐침을 할 수 있게 되었다. 이로 인해 프라이머 중합체의 원위치 중합효소 연쇄반응에서의 사용가능성을 타진하였다.

Treatment Cost Comparison and Development of Sustainability Indices for Microwave Soil Remediation of TPHs(Total Petroleum Hydrocarbons)

  • Kim, Dong Uk;Koo, Ja-Kong
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제20권5호
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    • pp.11-15
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    • 2015
  • The three processes of 1) high- & low-temperature microwave heatings, 2) the soil washing, and 3) the thermal desorption processes in soil remediation are analysed on the treatment cost data for 2003-2012 years. The cost of microwave heating method with at temperature 500-700℃, for 30 minutes, and at 4-6 kW is approximately 10 $/ton (13,000 ₩) due to the deep through heating of micro-wave, the soil washing with chemicals is about 80 $/ton (85,000 ₩) due to the chemicals & duration, and the thermal desorption process is around 40 $/ton (41,000 ₩) from the less efficiency. Furthermore the sustainability has been assessed, and suggestions are made. 1) Green; the minimal environmental footprint, 2) Growth; the least cost, 3) Shared; the social & environmental justice, 4) Smart; the microwave characteristics of deep through irradiation & heating, and 5) Mutuality; the flexibility of the technology. More additives including water, the government support, and public relation are suggested realizing the microwave in this condition is not harmful to human beings.