• 제목/요약/키워드: non-substitution model

검색결과 29건 처리시간 0.02초

Strength prediction of steady laminar fluid with normal velocity distribution: A simplified truncation technique

  • Mohamed A. Khadimallah;Muzamal Hussain;Elimam Ali;Abdelouahed Tounsi
    • Advances in concrete construction
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    • 제15권5호
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    • pp.313-319
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    • 2023
  • In this paper, the analytic solution has been found by using truncation approach. With the help of suitable substitution, different physical parameters are yielded in their non-dimensional form. The governing boundary layer partial differential equations are reduced to a set of ordinary ones by using appropriate similarity transformations. The velocity profile across the domain have also been taken into account. The effect normal velocity profiles buoyancy parameter, slip parameter, shrinking parameter, Casson fluid parameter on the heat profile. It is found that the normal velocity profiles rise with the buoyancy parameter and for the slip parameter. It is observed that the normal velocity profile decreases with the increase of shrinking parameter. The reverse behiour is found for the Casson fluid parameter. The results are numerically computed, analyzed and discussed. For the efficiency of present model, the results are compared with earlier investigations.

아이핀 기반 본인확인서비스의 안전성 강화 방안 (Safety Improvement Methods of Personal Identification Services using the i-Pin)

  • 김종배
    • 한국IT서비스학회지
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    • 제16권2호
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    • pp.97-110
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    • 2017
  • Due to development of IT, various Internet services via the non-face-to-face are increasing rapidly. In the past, the resident registration numbers (RRN) was used a mean of personal identification, but the use of RRN is prohibited by the relevant laws, and the personal identification services using alternative means are activated. According to the prohibition policy of RRN, i-PIN service appeared as an alternative means to identify a person. However, the user's knowledge-based i-PIN service continues to cause fraudulent issuance, account hijacking, and fraud attempts due to hacking accidents. Due to these problems, the usage rate of i-PIN service which performs a nationwide free personal identification service, is rapidly decreasing. Therefore, this paper proposes a technical safety enhancement method for security enhancement in the i-PIN-based personal identification service. In order to strengthen the security of i-PIN, this paper analyzes the encryption key exposure, key exchange and i-PIN authentication model problems of i-PIN and suggests countermeasures. Through the proposed paper, the i-PIN can be expected to be used more effectively as a substitution of RRN by suggesting measures to enhance the safety of personal identification information. Secured personal identification services will enable safer online non-face-to-face transactions. By securing the technical, institutional, and administrative safety of the i-PIN service, the usage rate will gradually increase.

Amino acid Thiohydantoin 유도체(誘導體)의 질량분석(質量分析) (제II보)(第II報) (Mass Spectrometric Identification of Thiohydantoins Derived from Amino Acids (II))

  • 송경덕
    • 한국식품영양과학회지
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    • 제3권1호
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    • pp.69-76
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    • 1974
  • The method of amino acid sequence determination from the C-terminal amino acid is proposed and mass spectrometric identification of thiohydantoins described previously. In this paper was discussed the fragmentation of thiohydantoin-ring by deutero substitution and model tripeptide have been degraded through three stages each, with interpretable results. The conditions employed in this method are mild enough for biological materials. The main features of the method are the following. 1. Thiohydantoins were formed in a non-aqueous medium a mixture of acetic anhydride, acetic acid and ammonium thiocyanate. 2. Mass sepectra of thiohydantoins derived from 20 amino acids were obtained with a mass spectrometer, JEOL model JMS-06H. 3. Cleavage of peptidyl thiohydantoin was made with an acidic from of a cation-exchange resin. (Amberlite IR-120) 4. Separation of the cleaved thiohydantoin and the parent peptide less one amino acid moiety was made by chromatography on a Sephadex G-10 column. 5. The peptide fraction was concentrated by freezedrying. 6. Thiohydantoin derivative of carboxyl terminal amino acid residue was introduced with a direct inlet probe in methanol solution.

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비시장재의 가치평가 : WTP의 추정과 부분-전체 편의의 검토 (Valuation of Nonmarketed Goods: WTP and Part-Whole Bias in CV Studies)

  • 박용치
    • 한국조사연구학회지:조사연구
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    • 제3권1호
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    • pp.1-24
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    • 2002
  • CV 연구에서는 연구대상에 대한 지불 용의액을 계산하는 것 못지 않게 연구과정에서 나타나는 여러 가지 편의 즉, 부분전체편의, 출발전 편의 등이 문제된다. 본 논문에서는 우리나라에 있는 4대강의 수질을 수영이 가능한 수질을 개선시킨다는 전제 아래 시민들은 얼마를 지불할 용의가 있는지를 추정하고, 이 과정에서 나타날 수 있는 부분-전체 편의의 문제를 검토하였다. 추정 결과 한강모델의 경우는 WTP가 5,435.69원이었고, 4대강 모델의 경우는 WTP가 7,182.68이었으며, 이 과정에서 부분-전체 편의는 존재하는 것으로 생각되며 그 원인으로는 대체효과와 순편의 효과로 설명된다.

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Synthesis and Luminescent Properties of Tetrafluorophenyl Containing Poly(p-phenylenevinylene) Derivatives

  • Ahn, Taek
    • Transactions on Electrical and Electronic Materials
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    • 제16권3호
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    • pp.162-167
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    • 2015
  • To investigate the effect of fluoro groups substitution on poly(p-phenylenevinylene) derivatives, poly(2,3,5,6- tetrafluoro-p-phenylenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene), PCTF-PPV, and poly[2,3,5,6-tetrafluoro-p-phenylenevinylene-alt-2-methoxy-5-(2-ethylhexyloxy)-p-phenylenevinylene], PMTF-PPV, were synthesized by the well-known Wittig condensation polymerization process. To compare the influences of fluoro groups, no fluoro groups containing model polymers, poly(p-phenylenevinylene-alt-N-ethylhexyl-3,6-carbazolevinylene), PCPPPV and poly[p-phenylenevinylene-alt-2-methoxy-5-(2-ethylhexyloxy)-p-phenylenevinylene], p-PMEH-PPV, were also synthesized. The resulting polymers were completely soluble in common organic solvents and exhibited good thermal stability up to 300℃. The polymers showed UV-visible absorbance and photoluminescence (PL) in the ranges of 259~452 nm and 500~580 nm, respectively. The tetrafluorophenyl containing PCTF-PPV and PMTF-PPV showed relatively red-shifted PL peaks at 521 nm and 580 nm, respectively, compared to that of non-fluoro groups containing polymers (PCP-PPV: 500 nm and p-PMEH-PPV: 539 nm). The single-layer light-emitting diode was fabricated in a configuration of ITO/polymer/Al. Electroluminescene (EL) emissions of PCP-PPV, PCTF-PPV, p-PMEH-PPV and PMTF-PPV were shown at 507, 524, 556, and 616 nm, respectively.

A CoMFA Study of Phenoxypyridine-Based JNK3 Inhibitors Using Various Partial Charge Schemes

  • Balasubramanian, Pavithra K.;Balupuri, Anand;Cho, Seung Joo
    • 통합자연과학논문집
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    • 제7권1호
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    • pp.45-49
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    • 2014
  • The (c-Jun N-terminal kinase 3) JNK3 is a potential therapeutic target for various neurological disorders. Here, a three dimensional quantitative structure-activity relationship (3D-QSAR) study on phenoxypyridine as JNK3 inhibitors was performed to rationalize the structural requirements responsible for the inhibitory activity of these compounds. The comparative molecular field analysis (CoMFA) using different partial atomic charges, was employed to understand the structural factors affecting JNK3 inhibitory potency. The Gasteiger-Marsili yielded a CoMFA model with cross-validated correlation coefficient ($q^2$) of 0.54 and non-cross-validated correlation coefficient ($r^2$) of 0.93 with five components. Furthermore, contour maps suggested that bulky substitution with oxygen atom in $R^3$ position could enhance the activity considerably. The work suggests that further chemical modifications of the compounds could lead to enhanced activity and could assist in the design of novel JNK3 inhibitors.

Magnetic-Tunnel-Junction 소자를 이용한 3비트 업/다운 카운터 (3-bit Up/Down Counter based on Magnetic-Tunnel-Junction Elements)

  • 이승연;김지현;이감영;양희정;이승준;신형순
    • 대한전자공학회논문지SD
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    • 제44권1호
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    • pp.1-7
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    • 2007
  • MTJ (Magnetic Tunneling Junction) 소자는 불 (Boolean) 연산을 수행할 수 있을 뿐만 아니라, 자신의 출력 정보를 저장하는 비휘발성 소자이다. 기존의 트랜지스터로 구성된 논리 연산자를 MTJ 소자로 대체함으로써, 조합논리 회로와 순차논리 회로로 구성된 디지털 논리 회로를 자기논리 (magneto-logic) 회로로 대체 가능하다. 또한 자기논리 회로는 비휘발성 논리 소자를 사용함으로써, 회로 면적 면에서 우수하고 전원이 꺼져도 정보를 유지할 수 있는 장점을 가지고 있다. 본 논문에서는 이러한 자기논리 회로의 예로 3비트 업/다운 카운터를 설계하였고 그 동작을 이전 논문에서 제안된 바 있는 macro-model을 보완 적용하여 검증하였다.

지역간 여가통행의 시간가치 산정 연구 (Estimating the Value of Travel Time for Intercity Leisure Trips)

  • 이장호
    • 대한교통학회지
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    • 제30권6호
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    • pp.59-70
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    • 2012
  • 주 5일 근무제 시행과 소득수준 향상 등으로 인하여 지역간 통행에 있어서 여가통행의 비중이 높아짐에 따라 철도사업의 합리적 평가를 위한 여가통행의 시간가치 산정 및 적용방안 등의 마련이 필요하게 되었다. 이에 따라 본 연구에서는 업무, 여가, 여가제외 비업무 통행에 대하여 수단선택모형을 구축하여 한계대체율법에 의한 시간가치를 산정하고, 이를 기초로 업무통행 대비 여가통행, 비업무통행의 비율을 도출하여 최종적으로 한계임금율법에 의한 통행목적별 시간가치를 산정하였다. 분석결과 여가통행은 타 비업무목적 통행에 비하여 시간가치가 높은 것으로 분석되었으며, 이를 사례분석에 적용한 결과에서도 비업무통행 시간가치를 적용하는 기존 방법론에 비하여 편익이 다소 증가하는 것으로 나타났다.

한일간 셔틀 운항 선박의 해사노동협약 선원휴식시간 규정 만족을 위한 연구 (A Study on the Compliance of Crew Rest Hour of Maritime Labour Convention for Shuttle Vessels Operating between Korea and Japan)

  • 하원재;김건효
    • 한국항해항만학회지
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    • 제38권2호
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    • pp.135-140
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    • 2014
  • 2013년 8월 20일 해사노동협약이 국제적으로 발효되면서 휴식시간의 실제적인 이행 여부를 항만국통제에서 점검하게 되었다. 한일간 셔틀 운항을 하는 선박은 항해시간이 짧고 입항 항구수가 많아 해사노동협약이나 우리나라 선원법에서 정하고 있는 선원휴식시간을 준수하지 못하는 경우가 발생하고 있으며, 이는 선박의 운항에 큰 지장을 초래할 수 있는 사항이 되었다. 이 연구에서는 이러한 선박들에서 휴식시간 규정을 준수할 수 있는 방안을 찾기 위해 항해사들의 당직모델을 여러 가지로 변경하거나 정박당직을 육상직원으로 대체하는 방안 등을 검토하였다. 한일간 셔틀 운항 선박이 휴식시간 규정을 만족하기 위해서는 입항 항구 수의 축소 또는 정박당직의 육상직원 대체와 같은 방안의 복합적인 적용이 필요한 것으로 연구되었다.

Impact Assessments of High Oil Prices on the Agro-Food System and the Role of Bioenergy Crops

  • Lee, Duu-Hwa;Lin, Hsin-Chun;Chang, Ching-Cheng;Hsu, Shih-Hsun;Chen, Chi-Chun;Sun, Jenny Chin-Hwa
    • 자원ㆍ환경경제연구
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    • 제16권3호
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    • pp.653-682
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    • 2007
  • In this study, multi-sectoral partial equilibrium and computable general equilibrium models of Taiwan are used to investigate the direct and indirect effects of energy price increases on overall economies and agro-food sector in Taiwan. The results suggest that agricultural prices, production cost would increase between 0.27% to 1.88%, and a reduction in GDP around 0.39% to 0.54 %. The negative impact on livestock sector is slightly higher than that on the crop sector. Negative impacts are also observed in the employment and wages. The rising oil price has the potential to discourage production of energy-intensive activity because of the possibility of substitution and adaptations. The growth rate of real GDP will shrink by 0.64% to 1.06% and CPI will increase by 1.17% to 1,95%. Both the agriculture and non-agricultural sector also respond by raising output prices by 0.80% to 1.33%. The rising international oil price has urged the government to take policy actions like using alternative fuels such as biodiesel, bioethanol, and adopting measures to cut down on energy consumptions mainly in transportation sectors in response to public concern over economic shocks.

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