• Title/Summary/Keyword: Size effect law

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Is it true?: A Meta-analysis on the Efficacy of CBCA in Detecting Truths (그 말은 진실일까?: CBCA의 진실 탐지 효용성에 대한 메타분석적 고찰)

  • Kim, Hye Jin;Lee, Sangmin;Hur, Taekyun;Choi, Seung-Hyuk
    • Korean Journal of Forensic Psychology
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    • v.12 no.2
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    • pp.121-149
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    • 2021
  • Statement Validity Analysis (SVA) is utilized in criminal investigations and the court to assess the credibility of given statements. During this procedure, the criteria for Criteria-Based Content Analysis (CBCA) are used to evaluate whether statements include the characteristics reflecting actual experiences about the event in question. Various studies had been conducted on the efficacy (classification rates) of CBCA criteria, yet the consistency of the findings was not investigated. In the current study, a meta-analysis was conducted with Korean CBCA studies reported from 2004 to 2020 (a total of fourteen studies). As a result, the total score of CBCA was found to successfully discriminate truth and fabrication. A significant positive (+) effect size was found with four criteria (3, 4, 10, and 12), all of which are classified as cognitive criteria. However, contrary to the underlying assumption for CBCA, criterion 18, classified as one of the motivational criteria, showed a significant negative (-) effect size. Meanwhile, moderator analyses were possible for eleven criteria (2~9, 12, 13, 15) and the results showed the significant effects of potential moderator variables such as the gender and status of the participants, study types and designs, number of raters, and publication status. The current results suggests that more careful attention is required to each criterion-especially the cognitive criteria-rather than the total CBCA score as well as the possible moderator effects in order to assess truthfulness of the statements. The implication, limitations, and suggestions for future studies were discussed.

A Study on Status Analysis and Improvement of Heavy Cargo Logistics (중량물 물류 실태 분석 및 개선 방안에 관한 연구)

  • Park, Du-Seon;Lee, Cheong-Hwan;Choi, Kyung-Hoon;Park, Gyei-Kark
    • Journal of Korea Port Economic Association
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    • v.33 no.3
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    • pp.35-52
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    • 2017
  • Interest and demand in heavy cargo logistics is increasing and becoming more diverse as economic scales have expanded and manufacturing activity has increased. Although cargo moves via maritime and/or land transportation, there is currently insufficient research on the actual condition of heavy cargo logistics. The purpose of this study is to carry out an in-depth analysis of heavy cargo laws, systems, logistics patterns, and current transportation status. By proposing measures to solve existing problems, this study aims to make an important and ongoing contribution to the scarcely studied field of heavy cargo logistics. The result of regression analysis on the main seven factors show that transportation frequency and law/system structure have a positive effect on working conditions. Furthermore, the result of correlation analysis on the main seven factors show that the cargo weight variable is highly positively correlated with cargo size. Also, the working conditions variable is highly positively correlated with the law/system structure. Detailed proposal measures to solve existing problems are summarized as follows. First, it is necessary to establish a clear concept of heavy cargo as numerous existing definitions differ. Second, laws and provisions relating to maritime and land transportation of heavy cargo need to be established and consolidated as current applicable legislation is insufficient. Third, the classification system for heavy cargo transportation needs improvement. Fourth, it is necessary to improve transportation performance statistics and the aggregate criteria system. Finally, the management system of heavy cargo also needs improvement.

Studies on the Extraction Rate of Oil from Sardine, Sardinops melanosticta (정어리 지질의 추출속도에 관한 연구)

  • YANG Hyun-Seok;LEE Keun-Tai;BYUN Dae-Seok
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.17 no.1
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    • pp.40-46
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    • 1984
  • The extraction ratio of oil using solvent from the muscle of sardine, Sardinops melanosticta, was studied. The results were critically evaluated in the light of the theory of oil diffusion in a porous solid model. In addition the effect of temperature and moisture on the extraction rate was examined. Sardine muscle was prepared in a manner to meet the conditions required by the diffusion theory from Fick's law. The results of the model were well coincidenced to the theory derived from Fick's law. Diffusion constants at the direction to muscle fiber($D_1$) and at direction perpendicular to fiber($D_2=D_3$) when extracted at $45^{\circ}C$ were $8.16{\times}10^{-8}cm^2/sec\;and\;4.12{\times}10^{-8}cm^2/sec$, respectivly. The extraction rate was linearly propotional to absolute temperature(T) by eleventh power under the constant condition of moisture contents and muscle size. A comparison of the experiments with the highest($74.22\%$) and the lowest ($32.48\%$) moisture indicated that difference of $1\%$ in moisture contents caused to change the slope(K) of the extraction curve $0.53{\times}10^{-6}sec^{-1}$ approximately.

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Temperature and Dependence of the Microhardness of Rhenium Sheets (리늄판의 미세경도 온도 및 응력의존성)

  • Yun, Seok-Yeong;Lagerlof, K.P.D.
    • Korean Journal of Materials Research
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    • v.10 no.5
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    • pp.335-342
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    • 2000
  • The microhardness of rhenium sheets was determined as a function of indentation load and temperature. The temperature dependence of the microhardness between room temperatures and $1000 ^{\circ}C$was studied using a hot microhardness tester equipped with a Vickers indenter. The load dependence of the microhardness was investigated using oth a Vickers and a Knoop indenter. The indentation size effect (ISE) was well explained using the normalized Meyers law. The hardness of the annealed rhenium sheet approached that of the as-rolled sheets at large indentation loads because of work-hardening under the indenter during indentation. The hardness at zero load(obtained from extrapolation of the load dependence of the hardness) suggested that the hardness is controlled by two different mech-anisms having different thermal activation. At low temperature the activation energy for the mechanism controlling the hardness was approximately 0.02 eV , Whereas at higher temperatures that was approximately 0.15eV. The tranisi-tion temperature between the two different controlling mechanisms was about $250^{\circ}C$.

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A Preliminary Study on the Co-author Network Analysis of Korean Library & Information Science Research Community (공저 네트워크 분석에 관한 기초연구 - 문헌정보학 분야 4개 학술지를 중심으로 -)

  • Lee, Soo-Sang
    • Journal of Korean Library and Information Science Society
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    • v.41 no.2
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    • pp.297-315
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    • 2010
  • This study investigates the various statistical data and measures of coauthorship network in the Korean LIS Research Community such as patterns of coauthorship, structural properties, types of cluster, centrality & impact analysis. This issues are mostly addressed through a Social Network Analysis of articles published from 2000 to 2009(10 years) in Korean Library & Information Science major four Journals. The coauthorship network was constructed and various measures of four centralities, PageRank, Effect size were calculated. The results show three implications. 1) There presents a phenomenon of Pareto's law in the articles publishing counts. 2) The top authors based on publishing counts prefer co-work publishing than solo-publishing. 3) The counts of article publishing are significantly correlated with five measures of network and not correlated with the case of power centrality.

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Study on Variation of Depth Dose Curves by the Strong Magnetic Fields : Monte Carlo Calculation for 10 MV X-rays (강자기장에 의한 깊이선량율(PDD) 변화에 관한 연구 : 10 MV 광자선에 대한 몬테칼로 계산)

  • 정동혁;김진기;김정기;신교철;김기환;김성규;김진영;오영기;지영훈
    • Progress in Medical Physics
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    • v.14 no.4
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    • pp.234-239
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    • 2003
  • We examined the variation of percent depth dose (PDD) curves for 10 MV X-rays in the presence of magnetic fields. The EGS4 Monte Carlo code was applied and modified to take account of the effect of electron deflection under magnetic field was used. We defined and tested DI (dose improvement) and DR (dose reduction) to describe variation of PDD curves under various magnetic fields. For a magnetic field of 3 T applied at the depth region of 5-10 cm and field size of 10${\times}$10 $\textrm{cm}^2$, the DI is 1.56 (56% improvement) and DR is 0.68 (32% reduction). We explained the results from the Lorentz law and the concept of electron equilibrium. We suggested that the dose optimization in radiotherapy can be achieved from using the characteristics of dose distributions under magnetic fields.

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Behaviour of Beams Without Transverse Reinforcement (전단보강근이 없는 보의 거동)

  • Cho, Soon-Ho
    • Magazine of the Korea Concrete Institute
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    • v.11 no.1
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    • pp.173-181
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    • 1999
  • To deepen the understanding of shear behaviour in beams without transverse reinforcement, the relative importance of five contributing factors to concrete shear resistance($v_c$), which are i)flexural compression zone, ii)friction at crack faces, iii)dowel action, iv)arch action and recently identified, v)residual tensile stresses across cracks, was explained physically using two analytical methods based on the truss concept. One is called "Modified Compression Field Theory(MCFT)" considering ii) and v) explicitly, and the other "Crack Friction Truss Model(CFTM)" more dominantly ii) in determining concrete resistance. To verify their effectiveness, the predictions using MCFT and CFTM were also made for twenty KAIST beam tests($f'_c$=53.7Mpa), designated more likely to the development of the size effect law based on the fracture mechanics concept. Experimental findings with varying of a/d, longitudinal reinforcement ratios, and obtained from MCFT enabled additional explanations for some phenomena which were difficult to measure in tests. However, MCFT seemed somewhat conservative for beams with higher longitudinal reinforcement, while somewhat unsafe for beams with larger depths. More tests are necessary leading to firm conclusions in these areas.

Characterization of aluminized RDX for chemical propulsion

  • Yoh, Jai-ick;Kim, Yoocheon;Kim, Bohoon;Kim, Minsung;Lee, Kyung-Cheol;Park, Jungsu;Yang, Seungho;Park, Honglae
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.3
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    • pp.418-424
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    • 2015
  • The chemical response of energetic materials is analyzed in terms of 1) the thermal decomposition under the thermal stimulus and 2) the reactive flow upon the mechanical impact, both of which give rise to an exothermic thermal runaway or an explosion. The present study aims at building a set of chemical kinetics that can precisely model both thermal and impact initiation of a heavily aluminized cyclotrimethylene-trinitramine (RDX) which contains 35% of aluminum. For a thermal decomposition model, the differential scanning calorimetry (DSC) measurement is used together with the Friedman isoconversional method for defining the frequency factor and activation energy in the form of Arrhenius rate law that are extracted from the evolution of product mass fraction. As for modelling the impact response, a series of unconfined rate stick data are used to construct the size effect curve which represents the relationship between detonation velocity and inverse radius of the sample. For validation of the modeled results, a cook-off test and a pressure chamber test are used to compare the predicted chemical response of the aluminized RDX that is either thermally or mechanically loaded.

반타원 표면균열의 피로성장 거동에 관한 연구

  • 최용식;양원호;방시항
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.6
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    • pp.916-922
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    • 1986
  • This paper presents the preliminary results of an experimental study on surface crack growth under fatigue loadings. The objective of this paper is to assess the effect of the initial crack size on crack propagation behaviors. Transparent PMMA plate speciments with shallow circular arc notch were used. Crack growth behaviors were observed and measured in two directions by travelling microscopes. The fatigue crack initiated at the deepest part on the initial arc shaped notch and then propagated to depth direction as well as spreading gradually along the notch tip. A considerable number of cycles was needed until the depth crack spreaded to the surface notch tip. When the fatigue crack reached the surface notch tip the crack front became an approximate semi-ellipse, primary semi-elliptical crack. Test results suggest that the relationships between fatigue crack growth rate and stress intensity factor range in both directions can be expressed by power law (Paris) and that relationship in width direction depends upon the crack ratios a$_{1}$/b$_{1}$, of the primary semi-elliptical crack. The relationship between the nondimensional crack lengths in both directions can be represented as the formula: (a/t)$^{n}$ =B(2b/W+A) where n and A are constants and B is seems to be depended upon the crack ratio a$_{1}$/b$_{1}$.

The Status, Problem and Improvement Method for Cross-ownership between Agency and Production (매니지먼트사와 외주제작사간 상호겸영 실태와 문제점 및 개선 방안)

  • Kim, Jeong-Seob
    • The Journal of the Korea Contents Association
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    • v.16 no.12
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    • pp.60-69
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    • 2016
  • Korean management agency and production's size is bigger than ever applying diversification strategy since the Korean Wave started in 2000. Thus, the cross-ownership between two sectors is widespread and it's side effect such as unfair trading occurred among them. Came up with this problem, this study has focused on the analysis of the cross-ownership status of the entire Korean listed agencies and productions and the quest of the alternatives to solve the problem through in-depth interviews of the stakeholders and experts. Results showed that the horizontal regulation and American regulatory systems should be applied considering the previous law because the cross-ownership level was so high. In conclusion, it was proposed three regulatory models as follows : first, accept the cross-ownership and prohibit casting their contracted actors in their art, second, ban on the cross-ownership and allow mutual investment within a 10 to 20 percent stake, third, blanket ban on the cross-ownership and investment.