• Explosives and Blasting
• /
• v.36 no.3
• /
• pp.1-9
• /
• 2018

This study was conducted to evaluate the influences of the angle of artificial joints, the distance between the artificial joints and the blast hole, and the number of artificial joints on the pressure wave propagation, crack propagation, and blast wave velocity. The evaluation was conducted numerically by use of the Euler-Lagrange solver supported by the AUTODYN, which is a dynamic FEM program. As a result, it was found that the blast wave velocity was decreased most rapidly as either the distance between the artificial joint and the blast hole was decreased or the angle of the artificial joint was increased. In contrast to the case of no artificial joint, the amount of attenuation of the blast wave velocity was considerably large when an artificial joint was present. However, the effect of the number of artificial joint on the attenuation of the blast wave velocity was negligible under the given condition.

• The Journal of Internal Korean Medicine
• /
• v.35 no.2
• /
• pp.145-156
• /
• 2014

Objectives : The aim of this study was to compare Tianwangbuxin-dan to Fluoxetine for antidepressive efficacy and safety in poststroke depression (PSD). Methods : A randomized, double blinded, non-inferiority trial was conducted. 113 PSD patients were recruited from a stroke center. Except for the 25 excluded patients, 88 PSD patients were randomly given either Tianwangbuxin-dan 1100 mg or Fluoxetine 20 mg per a day for 16 weeks. PSD was evaluated using Beck's depression inventory (BDI) and Hamilton depression rating scale (HDRS) and followed every fourth week. Repeated measure analysis of variance (ANOVA) was used to compare and contrast the depression scores of the two groups and to compare them among the evaluation times, at the beginning, $4^{th}$, $8^{th}$, $12^{th}$ and $16^{th}$ weeks. In addition, independent t-tests were used to find the difference between two groups at every evaluation time. Results : Finally, 88 PSD patients were included in the study, 63 PSD patients completed the procedure and 25 PSD patients were dropped out by the incompliance or withdrawal of consent. Tianwangbuxin-dan (or Fluoxetine) improved the depression of stroke patients and the efficacy of Tianwangbuxin-dan was not inferior to that of Fluoxetine. In addition, there was no significant side effect in two groups. Conclusions : This study showed that antidepressive efficacy and safety of Tianwangbuxin-dan in PSD patients.

• Journal of the Korea Convergence Society
• /
• v.9 no.1
• /
• pp.1-8
• /
• 2018

This study analyzed annual final sample data from 159 companies based on firms selected as economic justice companies by Economic Justice Institute in Citizens' Coalition for Economic Justice in South Korea according to interest variables from 2005 until 2011. Analyzed results are as follows. First, higher scores in soundness and corporate social activities among CSR items suggested that corporate credit rating upgraded. This indicates that credit rating institutions give a good evaluation on their social activities and reflect them in credit rating assessment. However, environmental protection satisfaction and corporate credit rating showed the opposite results. Second, high objectivity and contribution to the economic development as well as supervision by giant auditors had substantial effects on higher corporate credit rating. In contrast, high soundness and supervision by giant auditors reduced corporate credit rating. Based on this outcome, it is estimated that there is a discriminatory response among CSR activities in terms of credit rating evaluation conducted by credit rating institution.

• Korean Journal of Health Education and Promotion
• /
• v.21 no.3
• /
• pp.179-193
• /
• 2004

The potential contribution of the internet and mobile phone to smoking cessation seems huge, given that a majority of Koreans now use internet and have mobile phones. The Korean Ministry of Health and Welfare developed and has been offering an internet-based smoking cessation program from the January, 2002 and a mobile-based program from the April, 2004. Despite the anticipated effectiveness of internet and mobile-based smoking cessation programs, there is little empirical evidence regarding the efficacy of both types of programs. Therefore, this study intended to evaluate the effectiveness of an internet and a mobile-based smoking cessation program and to provide the basic database for the development of effective smoking cessation strategies for the health promotion for the whole nation. Cessation and satisfaction data were obtained from the 434 participants in both programs. The data were analysed for the comparison of quit-smoking rate and the degree of satisfaction between an internet smoking cessation program and a mobile smoking cessation program. The main results of this study were as follows: 1. For the internet program participants, there were statistically significant differences in cessation rate by gender(P<0.05) and age(P<0.01). In contrast, none of general characteristics provided statistically significant differences in cessation rate for the mobile program participants. 2. For the internet program participants, smoking related characteristics(average smoking amount and the reasons for smoking) didn't have an effect on smoking cessation. But, for mobile program participants, there was a statistically significant difference in cessation rate by the reasons for smoking(P<0.05). 3. The cessation rate was 31.9%(abstinence for the previous 30 days) for internet program participants and 17.8% for mobile program participants.

• Korean Journal of Legislative Studies
• /
• v.23 no.2
• /
• pp.147-177
• /
• 2017

Although a number of empirical studies found that political ideology plays a significant role in Korean elections, they entirely rely on cross-sectional data analysis. In contrast to previous research, this study investigates the effects of ideology in the 2012 Korean presidential election through standard panel data analysis. Specifically, using "EAI Panel Study, 2012", the effects of ideology on both candidate evaluation and vote choice were examined via fixed effects, random effects, and pooled regression analysis. And the results from applying the two most popular models of ideological voting, the proximity model and the directional change model were also compared. The results show that candidate evaluations and vote choice during the election (April, 2012- December, 2012) were significantly influenced by the ideological difference between voters and candidates, independent from partisanship and other standard socio-demographic factors. And this ideological voting during the election seems better captured by the directional change model than by the proximity model.

• Journal of the Korean Society of Food Culture
• /
• v.25 no.6
• /
• pp.764-769
• /
• 2010

The aim of this study was to examine how customers perceive storytelling at a real local restaurant and to understand how consumption reflects their evaluation by understanding their values. Participants received information from a real local restaurant in the Gangneung area to examine the effects of storytelling and to evaluate their affective attitudes towards local restaurant stories, word-of-mouth intentions, and purchasing intentions using a seven-point Likert scale. A total of 310 consumers were used. A factor analysis was performed to identify consumption value characteristics and factor structure, which consisted economic value, emotional value, and epistemic value. To test whether local restaurant consumers could be classified into homogenous groups based on their consumption values, a three cluster solution was selected, and a Kmeans cluster analysis was performed. As a result, three groups were identified and labeled appropriate for their scores based on each of the consumption values; emotional value-oriented consumers to cluster 1, epistemic value-oriented consumers to cluster 2, and economic value-oriented consumers to cluster 3. An analysis of variance was used to examine the differences in the affective attitudes towards storytelling at the local restaurant, purchasing intentions, and word-of-mouth intentions across the three clusters. The epistemic value-oriented consumers had the highest score for all three variables. In contrast, economic value-oriented consumers had the lowest scores for the three variables. A regression analysis revealed that affective attitudes towards storytelling were significantly affected by these three consumption values. It also showed that positive affective attitudes towards storytelling were associated with higher purchasing intention and word-of-mouth. The significance of this study was to show how customers perceive storytelling at a real restaurant and reflect on their evaluation by understanding their consumption values. As a result, this study examined the potential power of storytelling as an effective marketing communication tool for local restaurants.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.4
• /
• pp.129-142
• /
• 2016

This study performs an evaluation, using the economic feasibility analysis method, of the LTE based railway wireless networks (LTE-R) service that is planned to be used for the future railway networks in Korea. Its objectives are using the evaluation results and working to reflect the factors that lead to a maximization of benefits in designing an integrated railway wireless network. This study analyzes the impact of implementing an LTE-R on the railway networks, in contrast to the existing wireless network methods, e.g. VHR and TRS to new rail lines on an economic view. This results found that the benefit cost ratio is greater than 1.0 with a 10% contribution to benefits of the wireless network service in the case study on the Wonju-Gangneung rail line that will start operations in 2018; as a result, an ICT design is desired. For the introduction of an LTE-R service for the Wonju-Gangneung rail line, design specifications need to increase to benefits for each service, which will verify actual contributions and therefore result in an overall economic effect.

• Progress in Medical Physics
• /
• v.23 no.4
• /
• pp.252-260
• /
• 2012

The reduction of radiation dose from x-ray is a main concern in computed tomography (CT) imaging due to the side-effect of the dose on human body. Recently, the various methods for dose reduction have been studied in CT and one of the method is a iterative reconstruction based on total variation (TV) minimization at few-views data. In this paper, we evaluated the image quality between total variation (TV) minimization algorithm and Feldkam-Davis-kress (FDK) algorithm in micro computed tomography (CT). To evaluate the effect of TV minimization algorithm, we produced a cylindrical phantom including contrast media, water, air inserts. We can acquire maximum 400 projection views per rotation of the x-ray tube and detector. 20, 50, 90, 180 projection data were chosen for evaluating the level of image restoration by TV minimization. The phantom and mouse image reconstructed with FDK algorithm at 400 projection data used as a reference image for comparing with TV minimization and FDK algorithm at few-views. Contrast-to-noise ratio (CNR), Universal quality index (UQI) were used as a image evaluation metric. When projection data are not insufficient, our results show that the image quality of reconstructed with TV minimization is similar to reconstructed image with FDK at 400 view. In the cylindrical phantom study, the CNR of TV image was 5.86, FDK image was 5.65 and FDK-reference was 5.98 at 90-views. The CNR of TV image 0.21 higher than FDK image CNR at 90-views. UQI of TV image was 0.99 and FDK image was 0.81 at 90-views. where, the number of projection is 90, the UQI of TV image 0.18 higher than FDK image at 90-views. In the mouse study UQI of TV image was 0.91, FDK was 0.83 at 90-views. the UQI of TV image 0.08 higher than FDK image at 90-views. In cylindrical phantom image and mouse image study, TV minimization algorithm shows the best performance in artifact reduction and preserving edges at few view data. Therefore, TV minimization can potentially be expected to reduce patient dose in clinics.

• Food Science of Animal Resources
• /
• v.33 no.2
• /
• pp.287-293
• /
• 2013

This study was conducted to investigate the effect of quality grade on the physicochemical and sensory properties of Hanwoo beef on the basis of four quality grades (grade $1^{{+}{+}}$, $1^{+}$, 1, and 2). Significantly decreased levels of myoglobin content (from 12.73 mg/g to 7.90 mg/g) and Warner-Bratzler shear force (WBs) (from 28.01 kg to 14.03 kg) were found with reduction in quality grade (p<0.05). In contrast, increasing quality grade correlated with significant increase in crude fat contents (from 8.18% to 19.55%). Crude fat contents showed a negative correlation with moisture content (r=-0.966), myoglobin content (r=-0.998), and WBs (r=-0.969). In sensory evaluation experiments it was revealed that quality grades were associated with significantly altered (all p<0.05) flavor, taste, juiciness, tenderness, and overall acceptability. Moisture contents showed negative correlation with taste (r=-0.969) and overall acceptability (r=-0.988). Crude fat contents showed significant correlation with taste (r=0.971), tenderness (r=0.983) and overall acceptability (r=0.968). WBs showed negative correlation with taste (r=-0.957) and overall acceptability (-0.978). The marbling score of fresh meat showed significant correlation with taste (r=0.958), juiciness (r=0.953), and overall acceptance of cooked meat. These results could be used as a fundamental dataset to evaluate the effect of quality grade on the physicochemical and sensory characteristics of Hanwoo beef.

• The Journal of the Korean dental association
• /
• v.54 no.11
• /
• pp.865-873
• /
• 2016

Background/Purpose: The purpose of this study was to evaluate the effect of Nd:YAG irradiation on adherence of retrograde filling materials (mineral trioxide aggregate [MTA] and Super-EBA) by micro-computed tomography (CT) measurement and to observe the dentinal surface after irradiation by scanning electron microscopy (SEM). Materials and methods: Forty retrofilling models using extracted human teeth were divided into four groups according to the material and method used: ProRoot MTA (MTA group), Super-EBA (EBA group), MTA with Nd:YAG laser irradiation (LMTA group), and Super-EBA with Nd:YAG laser irradiation (LEBA group). All specimens were stored in 100% humidity for 24 hours until micro-CT was performed. The gap volume of the tooth/material interface was measured using the CTAn program. In six samples, the laser-irradiated dentin surface was observed using SEM. Results: The mean percent difference in gap volume was not statistically significant between the Nd:YAG laser-irradiated groups and non-irradiated in both materials(P > 0.05). The gap volume in the MTA group was significantly lower than that in the EBA group (P < 0.05). Examination of the non-irradiated specimens by SEM showed patent dentinal tubules. In contrast, alterations in the texture of the dentin surface and obliteration of the dentinal tubules were evident in the Nd:YAG laser-irradiated specimens. Conclusion: In this study, changes in the dentinal surface after Nd:YAG irradiation did not affect adherence between the apical filling material and the dentin wall.