• Environmental Engineering Research
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• 제24권4호
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• pp.529-542
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• 2019

Nowadays, drying methods for municipal solid waste quality improvement have been adopted in the developed and developing countries to valorize wastes for a renewable energy source, reduce dependency on fossil fuel and keep safer disposal at landfills. Among them, biodrying, biostabilization, thermal drying and solar drying are the most common. Drying of municipal solid waste could offer several environmental and economic benefits. Therefore, this review highlighted the drying methods for municipal solid waste quality improvement around the world and compared them based on the reduction of moisture, weight and volume of municipal solid wastes against drying temperature and time by using statistical analysis. It was observed that the drying temperature of different drying methods accounted for 115 ± 40℃ for thermal drying, 59 ± 37℃ for solar drying, 55 ± 15℃ for biodrying and 58 ± 11℃ for biostabilization. Among the drying methods, thermal drying provided the shortest drying time. The moisture reduction, weight reduction, volume reduction and heating value increase of municipal solid waste could vary with drying temperature and time. Finally, the benefits and drawbacks of different drying methods were specified, and recommendations were made for the future efficient drying.

• Restorative Dentistry and Endodontics
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• 제49권2호
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• pp.16.1-16.10
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• 2024

Objectives: This cross-sectional study evaluated the prevalence of apical periodontitis (AP) and the technical quality of root canal fillings in an adult Kuwaiti subpopulation using cone-beam computed tomography (CBCT) images. Materials and Methods: Two experienced examiners analyzed 250 CBCT images obtained from Kuwaiti patients aged 15-65 years who attended government dental specialist clinics between January 2019 and September 2020. The assessment followed the radiographic scoring criteria proposed by De Moor for periapical status and the technical quality of root canal filling. Chi-square and Fisher's exact tests were used for statistical analysis, with significance level set at p < 0.05. Results: Among the 2,762 examined teeth, 191 (6.91%) exhibited radiographic signs of AP, and 176 (6.37%) had undergone root canal filling. AP prevalence in root canal-treated teeth was 32.38%, with a significant difference between males and females. Most of the endodontically treated teeth exhibited adequate root canal filling (71.5%). Conclusions: The study demonstrated a comparable prevalence of AP and satisfactory execution of root canal treatment compared to similar studies in different countries.

• 한국대기환경학회지
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• 제19권1호
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• pp.93-100
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• 2003

본 연구에서는 세가지 통계적 기법을 적용하여 고산에서 측정한 TSP (Total Suspended Particle) 농도 특성을 해석하였다. 우선 황사와 비황사시의 평균농도를 비교하는 t-검정의 기본가정을 점검하였다. 모집단을 정규분포화 하기 위해 당량농도를 Log 변환하였고 이로써 1992~1999년 봄철 황사시 평균농도가 비황사시 평균농도보다 높은 이온 성분은 NH$_4$$^{+}$ 뿐임을 확인하였다. 통계적 검정을 수행함에 있어서 기본 가정을 확인하는 것은 중요한 과정이다. 또한 봄철에 집중되어 있는 TSP측정기간이 평균값에 미치게 될 영향을 제거하기 위해 측정일수를 유사하게 맞추었다. 측정일수를 맞추어 산정한 평균값과 측정일수가 다른대로 산정한 평균값을 비교해본 결과, 기간별 측정일수가 다름은 평균값에 영향을 미치나 큰 변화는 보이지 않았다. 마지막으로 비모수 통계기법을 이용해 nss-SO$_4$$^{2-}$ NO$_3$$^{-}$ 과 S/N 비의 경향성을 분석해본 결과, nss-SO$_4$$^{2-}$ 의 경우 통계적으로 그 경향성은 나타나지 않고 NO$_3$$^{-}$만이 증가경향을 나타내었으며, 따라서 증가하는 경향성을 보인 S/N 비는 NO$_3$$^{-}$ 에 의한 감소의 경향을 나타냄을 통계 적으로 확인하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1994년도 추계학술발표회
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• pp.49-58
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• 1994

The methods of estimation of VTS effectivenss are compared and the worldwide literature related to the VTS effectiveness is reviewed. The review suggests three potential approaches ; simulation ; synthesis of expert opinion and statistical analysis of casualties. this study adopted dissimilar approaches to estimate the VTS effectiveness to the earlier studies ; the combination of synthesis of expert opinion and causal analysis of casualty. The VTS effectiveness is derived by multiplying casualty rate reduction factors by the effect level of causal factors. The development of casualty rate reduction factors was based on the questionnaire survey and the evolution of effect levels was based on the causal analysis using functional block diagram. According to these procedures the maximum benefit to be obtained through the introduction of a VTS system was approximately 46 percent overall. The collision reduction rate was estimated to be approximately 50 percent for a VTS system with advanced radar surveillance. And 47 percent of groundings 36 percent of rammings and 21 percent of founderings could be reduced by the introduction of VTS. These figures are more or less the same to the earlier studies. The VTS effectiveness by the different causal factor groups was examined. VTS may reduce about 68 percent of causal factors classified as environmental conditions 40 percent of human factors and 35 percent of technical factors in collision accidents. As a whole 60 percent of environmental factors 41 percent of human factors and 20 percent of technical factors may be prevented by a VTS. The key variable of the effectiveness percentage is the value of weight coefficient $\delta$. Therefore differing values for this input was discussed and the impact that these variations have on the VS effectiveness noted. As the results of sensitivity analysis of VTS effectiveness by $\pm$10 percent the effectiveness is varied approximately three to seven percent by casualty type. And the value is changed roughly four to eight percent by a $\pm$10 percent variation by different sub-areas.

• 가족자원경영과 정책
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• 제23권4호
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• pp.57-73
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• 2019

This study explored how communication between married men and women is related to marital satisfaction, and verified the relationship through the medium effect of marital intimacy. A total number of 365 married men and women in their 30s-50s were surveyed. Statistical analysis was performed using SPSS 18.0 for technical statistics, frequency analysis, and regression analysis, and parametric analysis was performed using the method by Baron and Kenny(1986). The results of the study are as follows. First, as a result of the verification of differences in key variables according to the demographic characteristics, there were significant differences in the age group, education period and household income. Second, the analysis of the relationship through regression analysis shows that the demographic factors such as age, age of the youngest child, and more importantly couple communication, and marital intimacy are influential in marital satisfaction. Third, verification of the mediation analysis revealed that marital intimacy had partial mediation with communication and marital satisfaction. Through these research results, we verified that marital communication and marital intimacy are vital in order to improve marriage satisfaction for married men and women.

• 한국항만경제학회지
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• 제34권1호
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• pp.51-64
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• 2018

본 고는 Malmquist 생산성 지수를 이용하여 글로벌 금융위기 이전인 2001-2008년, 그 이후인 2008-2015년 두 기간 동안 조선 산업의 생산성변화를 기술효율성변화, 순효율성변화, 규모효율성변화, 기술변화로 구분하여 측정함과 동시에 두 기간 동안 생산성 변화를 비교하였다. 전반기(2001-2008년)에는 2.8%의 생산성 향상되었으며, 이는 기술효율성 보다는 기술진보에 기인된 것으로 나타났다. 후반기(2008-2015)에는 -3.4%의 생산성 하락으로 나타났다. 이는 글로벌 금융위기이후 세계경제의 침체로 인한 선박수주 물량의 감소, 중국 조선 산업의 부상 등으로 인해 기술효율성 저하, 기술퇴보 등에 기인된 것으로 나타났다. 두 기간 중 전반기 가 후반기보다 생산성이 높게 나타났다. 특히 두 기간 간에 이러한 차이는 기술변화에 의해 기인된 것으로, 즉, 기술 퇴보는 생산성 감소로 나타났으며, 통계적 검증을 통해서도 이를 입증할 수 있었다. 본 연구 결과에 의한 정책적 시사점으로는 정부 그리고 각 DMU들은 향후 생산성 증대를 위해, 글로벌 조선 산업의 환경변화에 대응하는 신기술개발 그리고 비효율적 요인을 제거하는 전략이 필요하다는 점을 제시하고 있다.

• 안보군사학연구
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• 통권5호
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• pp.241-280
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• 2007

This study examines the relationship of the industry-specific factors that effect innovation of manufacturing technology and the market share within the defense industry. Since the establishment of the basic defense industry framework in 1973, there were numerous interactions of the industry-specific factors of the defense industry structure with the technological innovation and market organization of the defense industry. During last three decades, the domestic defense industry has achieved the considerable level but the framework of the basic system has not developed much in areas of the military science and the defense manufacturing technology. Industry-specific factors were formed in the process and appeared in a variety of behavioral characteristics as subsystems. Currently, there IS a growing trend where the management of defense industry is gradually deteriorating due to limitation of the domestic industry-specific factor (e.g. defense technologies, amount of demand, etc.). If there is a prominent imbalance of the industry-specific factors. it can trigger the potential problem of conflict, lack of cooperation and control, slowing the growth of the manufacturing technology thereby diminishing the market and deteriorating the defense supply/demand relationship. In a research conducted by Joe S. Bain, Bain analyzed the relationship of the traditional industrial organization where industry-specific factor(S) not only impacts the conductor(C). And, conductor(C) influences the shaping of the performance(P) of relationship of the traditional industrial organization. Consequently, the researcher has identified the demand monopoly, barriers to entry, and market competition with comparison of defense industry issues. These defense issues were three industry-specific factors identified, which are 1) The demand monopoly and The entry barriers to new market competition, 2) the industrial technical factor to a production technical competitiveness and a market sharing competitiveness, 3) the probability factor to revolution for military affairs(RMA) and a R&D production. According to baseline with these factors, the following research model is established from the special companies group(Group A), the systematization companies group(Group B), and the general companies group(Group 0. The hypothesis is that if there are more industry-specific factors, then there will be more relationships of defense industry relation statutes. This research is an empirical study on the relationship that the industry specific factors effects the innovation of manufacturing technology and the shaping of the market in the defense industry. Moreover, the existing models to evaluate the industry specific factors of the defense industry IS much to be desired with the controlled statistical analysis of the result. It is vital to study on current situation with suggesting alternative strategy to the efficient strategy. The descriptive analysis approach analysis is conducted with SPSSWIN to conduct reliability test, factor analysis, correlation analysis, cross-tabulation analysis, one-way ANOVA, and multiple regression analysis. However, there were some limitations of the survey such as the rigidity of concept about the technical factors and various market management factors. The wishes is that the decision-maker could be utilized these defence industrial factors to formulate efficient defence policy and strategy in the future.

• 가족자원경영과 정책
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• 제23권4호
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• pp.41-56
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• 2019

The purpose of this study is to investigate the effects of economic status on the difficulties of family life focusing on the mediating effects of family communication and family ties. A total of 386 people were surveyed, and data from 352 were used for the actual data analysis. For the analysis, technical statistical analysis, correlation analysis, regression analysis, and a Sobel test were conducted. The results were as follows.: First, the correlation analysis confirmed that there are statistically significant correlations among the economic status of households, family communication, family ties, and the difficulties of family life. Second, the economic status of households directly influences the difficulties of family by mediating family communication and family ties. This study identified that family communication and family ties affect the improvement of difficulties in family life. It suggests that improving economic status, promoting communication among family members, and strengthening family ties can help solve the difficulties of family life.

• 가족자원경영과 정책
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• 제22권4호
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• pp.61-74
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• 2018

The purpose of this study is to verify the mediating effect of self-efficacy in relation to marriage satisfaction and the social support of immigrant women. The research data for the analysis were collected from those who using multi-cultural family support centers in Siheung of Gyeonggi-do and Ansan from September 30 to October 21, 2017, and a total of 223 people were used in the final analysis. The analysis methods examined the characteristics of the subjects through frequency analysis and technical statistics, and a hierarchical regression analysis was performed to verify the effectiveness of mediator effects. The statistical program used SPSS 22.0. The analysis showed that social support and self-efficacy of married immigrant women had a significant impact on marital satisfaction. In addition, self - efficacy had a partial mediating effect on the relationship between the social support of married immigrant women and marital satisfaction. Based on these results, we discussed practical implications for social support and self-efficacy to improve marriage satisfaction of married immigrant women.

• International Journal of Computer Science & Network Security
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• 제24권7호
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• pp.87-100
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• 2024

Modern logistics significantly influences the globalization and internationalization processes. Logistics systems are becoming increasingly important in today's rapidly changing environment. On the other hand, the development of global economic integration, business globalization contributes to the creation and development of international logistics systems and global supply chains towards the international market. The aim of the article was to investigate the national logistics systems of developing countries in the context of their integration capabilities. The main methods used in this study are statistical analysis, index, graphical and analytical methods, methods for estimating structural dynamic shifts, comparisons. Commonly used methods of economic research, as well as statistical analysis and interstate comparisons, economic modelling (trend analysis to determine the forecast level of LPI for Ukraine), etc. were also involved. It is noted that the problem of development of logistics systems in developing countries was insufficiently covered in scientific research. The study suggests that the integration capabilities of national logistics systems are determined by the logistics performance of each country and the favourable logistics environment for integration transformations. This allowed analysing the state of the logistics systems of Poland, Bulgaria, India and Ukraine, and identifying the factors that determine it. The logistics environment of Poland, Bulgaria, India and Ukraine, as well as the factors of its formation are evaluated. The components of the logistic portrait of the country in the context of integration capabilities of the logistic system are offered. Trend analysis of LPI was carried out on the example of Ukraine, which showed positive trends in the logistics system and allowed drawing conclusions about increasing integration into international logistics channels based on its geopolitical location, improving the characteristics of the logistics environment, including customs regulation, and improving the efficiency of the national logistics system. Prospects for further research involve studies of the impact of pandemics, globalization, digitalization on logistics systems, including that of developing countries.