• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.175-186
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• 2013

Based on Model Code 2010, flexural and residual strength, flexural toughness of SFRC with design strength of 60 MPa are evaluated. For comparisons, SFRC with design strength 40 MPa was tested. Distribution of steel fibers in crack surface of specimens was evaluated by visual inspection. The used steel fibers were hooked fibers with aspect ratio of 64, 67 and 80. In all specimens, mix ratio of steel fibers was 0.5% Vol. In results, only SFRC with the highest aspect ratio satisfied requirements specified in Model Code 2010. The results demonstrated that the use of high aspect ratio will provide enough flexural toughness for high strength concrete. Also, it is found that low slump of high strength concrete can help to enhance isotropic fiber distribution.

• Tunnel and Underground Space
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• v.14 no.5
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• pp.363-372
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• 2004

Double torsion (DT) tests were carried out to investigate the influence of the geometry of guide groove on stress corrosion index of Kumamoto andesite. The fracture toughness was measured in the constant displacement rate, which was set to 2.07 MN/m$^{3}$2/ in average regardless of crack velocity. Stress corrosion indices, n were evaluated using specimens with rectangular, circular and triangular grooves and were 37, 36 and 38 in average, respectively. The n values were constant regardless of the groove geometry, however the DT specimen with triangular groove geometry showed the largest standard deviation in the relationship between crack velocity and stress intensity factor. The DT test was found to be effective in using a rectangular-grooved specimen and the width of the groove must be greater than the average grain size of minerals.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.2
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• pp.85-89
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• 2019

Objectives : The purpose of this study was to quantitatively assess the degree of myasthenia gravis (MG) affecting mental health through the results of multiphasic military personality inventory in late adolescence. Methods : We collected and analyzed the results of the military personality inventory for healthy controls and MG patients among the 19-year-old men who visited the Military Manpower Administration from February 2007 to January 2010. Military personality inventory invented for Korean military test has similar system to Minnesota multiphasic personality inventory. Results : Among validity scales, each score of faking good, faking bad and infrequency subscales showed no difference between healthy control and MG groups, respectively (t=-0.51, p=0.607 ; t=0.11, p=0.913 ; t=1.41, p=0.158). Among neurosis scales, the score of somatization subscale was higher (t=2.29, p=0.023) in MG group. Among psychopath scales, the score of schizophrenia subscale was lower in MG group (t=-2.38, p=0.018). Conclusions : According to MPI results, we can confirm that MG patients in late adolescence may be more concerned with their somatic symptoms than the control group, and that they may be more likely to abide by the regulation and be conventional in their behavior than the control group.

• The Korean Journal of Nuclear Medicine
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• v.28 no.3
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• pp.371-376
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• 1994

To reevaluate the clinical usefulness of erection penography for diffential diagnosis of impotence, we reviewed retrospectively the data of penography in 56 patients who were diagnosed as impotence by various diagnostic workup. Twelve normal males were studied as control group. Papaverine HCl 30mg was injected into the corpus cavernosum and simultaneously $^{99m}Tc$-HSA 20mCi was injected via an antecubital vein. After injection radioactivities in the penile area were detected for 30 minutes by gamma camera and time activity curve was displayed. We defined that transit time(TT) is the time to reach peak activity and erection persistent time(EPT) is the duration of time to maintain peak activity and venous index(VI) is the ratio of radioactivity($R_{30}/R_{max}$). The results were as follows. The TT of arteriogenic group($10.7{\pm}2.8min$) was significantly increased compared with those of control and venogenic groups(P<0.05, respectively). The EPT of venogenic group ($6.2{\pm}6.8min$) is significantly decreased compared with those of control and arteriogenic groups(P<0.05, respectively). The TT of psychogenic($15.2{\pm}5.5min$) is significantly increased compared with those of control and arteriogenic groups(P<0.05, respectively). In conclusion erection penography was very useful for the diagnosis of vascular and psychogenic impotence and for differentiation between arteriogenic and venogenic but it could not differentiate mixed type or neurogenic from vascular or psychogenic.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.19-32
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• 2015

This research was performed to provide a basic data for reforming University and Hotel & Tourism Management Curriculum Framework based on competency-based education, especially through identifying university students' competency categories of that reflect on the specialization and major of university. For the purpose of this research first, based on the literature review and empirical study, this paper grouped competencies into four areas: Generic Competencies, Specific Competencies, Personality Competencies, and University Specialization Competencies. Second, this paper examined empirical test through a survey of university students by Importance-Performance Analysis on four main categories. As a result of empirical test, four main categories were statistically verified, and the differences among majors about importance, performance and educational needs of each four competencies were analyzed significantly. There were proved that hospitality major is higher than other majors in importance of Generic and Personality Competency and performance of Generic Competency as well.

• Korean Journal of Materials Research
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• v.10 no.12
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• pp.838-844
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• 2000

For the fabrication of titanium diboride($TiB_2$)- based cermet as applications of cutting tools and wear resistant materials, a binder metal with good mechanical properties and sinterability is essential. In this study, SUS316L was chosen for the binder metal to obtain a new $TiB_2$ cermet with superior hardness and toughness.$TiB_2$-SUS316L cermets were densified to relative density of more than 99% by pressureless sintering at temperature above $1650^{\circ}C$ The flexural strength was up to 1290MPa at 10vo1%SUS316L cermet in spite of the formation of $Fe_2$B phase during the sintering. The fracture toughness was obtained up to $6MPam^{1/2}$ with Victors hardness over 18Gpa. These hardness and fracture toughness combinations are better than those of conventional cermet. The high temperature strength remarkably decreased by the plastic deformations of SUS316L binder phase at nearby $800^{\circ}C$ .

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1056-1073
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• 2011

The purpose of this study was to develop teaching materials using Pyramid model of divergent thinking, Inverse pyramid model of convergent thinking and Diamond model of divergent-convergent thinking. And the teaching materials was implemented to 120 students in middle school over 10 weeks. Results indicated that the experimental group presented statistically meaningful improvement in creative thinking skills, especially in fluency and flexibility(p<.05). Also the teaching materials contributed to improve critical thinking skills, especially in inquiry process of recognizing problems, making conclusion and generalization(p<.05). Moreover, academic achievement was improved(p<.05). But, there was no significant improvement in creative personality(p<.05).

• Korean Security Journal
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• no.16
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• pp.209-228
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• 2008

It is possible to contribute to efficiency of police organization if policeman has their hob satisfaction. To effectively perform the service, it is important to a matter of outcome or satisfaction of duty. However, the study in this field is insufficient. In this study, the introduction is in the first chapter. Theoretical consideration in the second chapter, investigative analysis and argument in the third chapter and finally the conclusion in the forth chapter. In this study, according to analysis of position, personality show no differences and job satisfaction show more higher in police sergeant class. Also, the study shows that there is relationship between sociality and prudence and outcome of duty and occupational view in the correlation between personality and job satisfaction. Therefore, a sociable person influence affirmative occupational view and outcome of duty.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.458-461
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• 2002

This study presents development of a machine for shrink wrapping of cans or drink bottles with thermoplastic films. The accurate position-control, the safety factor of chains, the reduction-ratio of the chain and gear, the appropriate heating temperature for banding vinyl are discussed for the optimum shrink wrapping M/C design.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1992.03a
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• pp.47-58
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• 1992

탄소성 재료의 파괴에서 최대하중을 계산할 수 있는 방법이 제시되었다. 사용된 재 료상수는 파괴개시인성, 항복강도, 진행된 균열선단에서 열림 변위 증분에 대한 균열성장의 비이고, 계산을 실험결과에 맞추어 재료상수를 결정한다. 이들 상수로 다른 시편의 최대하 중을 계산하는 간단한 방법을 평면변형하의 A572 강(상온)과 4533(B)강(-10C)에 적용하여 기존의 실험결과와 비교하였다. 또한 균열 선단 열림 변위와 J-적분값에 기초한 다른 방법 과 비교·논의되었다.