• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권2호
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• pp.116-120
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• 2008

Clustering is a method for unsupervised learning. General clustering tools have been depended on statistical methods and machine learning algorithms. One of the popular clustering algorithms based on machine learning is the self organizing map(SOM). SOM is a neural networks model for clustering. SOM and extended SOM have been used in diverse classification and clustering fields such as data mining. But, SOM has had a problem determining optimal number of clusters. In this paper, we propose an improvement of SOM using gap statistic and probability distribution. The gap statistic was introduced to estimate the number of clusters in a dataset. We use gap statistic for settling the problem of SOM. Also, in our research, weights of feature nodes are updated by probability distribution. After complete updating according to prior and posterior distributions, the weights of SOM have probability distributions for optima clustering. To verify improved performance of our work, we make experiments compared with other learning algorithms using simulation data sets.

• 응용통계연구
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• 제32권3호
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• pp.331-348
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• 2019

전이성 종양의 성장패턴 차이와 변화율에 따른 종양 이질성(tumor heterogeneity)을 파악하는 것은 종양세포의 약물에 대한 민감성을 파악하고 적절한 치료법을 찾아내기 위해 중요하다. 일반적으로 N개의 표본의 집단이 구분된다면 t-test 혹은 ANOVA 분석을 통해 집단별 평균의 차이에 대한 검정이 가능하다. 그러나 본 논문에서 다루는 데이터와 같이 집단이 구분되지 않는 경우 이러한 방법들은 사용될 수 없다. 표본들 사이의 이질성을 검정하기 위한 통계적 방법들이 연구되어 왔다. 최소 조합 t-검정 방법은 그 중 하나이다. 본 논문에서는 상이한 비율로 데이터를 양분하는 조합도 고려하는 최대 조합 t-검정 방법을 제안한다. 한편, 표본의 이질성을 검정하는 것이 군집분석에서 최적의 군집의 개수가 2개 이상인지를 검정하는 것과 같음에 착안하여 새로운 방법을 제안한다. 최대 조합 t-검정과 gap통계량을 이용하면 이전에 제안된 방법보다 개선된 제1종의 오류를 범할 확률과 검정력을 갖는다는 것을 모의실험을 통해 확인하였고 실제 자료 분석을 통해 결과를 도출하였다.

• 한국항만경제학회지
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• 제28권4호
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• pp.231-255
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• 2012

선박조직은 육상과 일정기간 격리된 상황에서 육상조직과의 커뮤니케이션을 업무를 수행하고 있으므로, 해상-육상간의 커뮤니케이션이 중요하다. 그런데 해운기업의 육상조직과 선박조직 사이에는 육상조직의 일방적 커뮤니케이션의 문제점과 부정적 결과들이 제기되고 있다. 본 연구는 선박조직과 육상의 선박관리 부서 간에 이루어지는 커뮤니케이션과 갈등의 문제를 선박조직과 육상부서 양쪽 집단을 대상으로 진단하고 분석하여 객관적이며 종합적으로 규명해 보고자 하였다. 해운기업의 선박조직과 육상 선박관리 부서간의 커뮤니케이션에 따르는 부정적 영향으로서 집단 간 갈등에 주목하여 커뮤니케이션과 집단 간 갈등의 수준과 갭을 측정하여 이들의 관계를 규명하고, 집단 간 갈등이 선박조직의 조직몰입과 직무만족에 미치는 영향을 분석하였다. 선박조직과 육상부서의 상대집단과의 커뮤니케이션 활성화 정도는 상대집단과의 집단 간 갈등에 통계적으로 유의미한 부(-)의 영향을 미치며, 상대집단에 대한 집단 갈등은 선박조직의 조직몰입과 직무만족에 부(-)의 영향을 미치는 것으로 나타났다. 그리고 양쪽 집단의 커뮤니케이션과 집단 간 갈등의 갭 분석에서 있어서는 커뮤니케이션이 모두 활성화되어 인식 차이가 적은 그룹에서 집단 간 갈등의 인식 수준이 낮았으며, 집단 간 갈등의 인식차이가 낮은 그룹의 선박조직 조직몰입도와 직무만족도가 가장 높은 것으로 나타났다. 따라서 해운기업의 선박조직과 육상의 선박관리부서는 양쪽 모두의 원활한 커뮤니케이션을 통해 상대집단과의 갈등을 줄이고 선박조직 구성원의 조직몰입도와 직무만족도를 제고하여야 할 것이다.

• Archives of Plastic Surgery
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• 제32권5호
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• pp.613-618
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• 2005

When a large peripheral nerve defect occurs, an autologous nerve graft is the most ideal method of recinstruction. But an autologous nerve graft has many limitations due to donor site morbidities. Many previous focused on finding the ideal nerve conduit. Among them, $Gore-Tex^{(R)}$ has several advantages over other conduits. It can be manipulated to a suitable size, does not collapse easily, and it is a semi- permeable material that contain pores. A round shaped nerve can be newly formed because of its smooth inner surface. The purpose of this study was to evaluate the availability of $Gore-Tex^{(R)}$ tube as a nerve conduit at the peripheral nerve defect in the rat sciatic nerve. The 10 mm nerve gap was made in each group. A $Gore-Tex^{(R)}$ tube filled with skeletal muscle was inserted and autologous nerve graft was harvested, respectively. In the experimental group, we placed a 0.5 mm thickness, $30{\mu}m$ pored, 1.8 mm in diameter and 14 mm length tube with skeletal muscle inserted inside. In the control group, the nerve gap was inserted with a rat sciatic nerve. We estimated the results electrophysiologically and histologically to 16 weeks postoperatively. Results in the nerve conduction velocity, total myelinated axon count, myelin sheath thickness and mean nerve fiber diameter, the experimental group was substantially lower than that of the control group, but the statistic difference was not significant (p<0.05). The morphology was very similar in both groups, microscopically. From the above results, We conclude that $Gore-Tex^{(R)}$ qualifies as an ideal nerve conduit. It is suggested that $Gore-Tex^{(R)}$ tube filled with skeletal muscle may, substitute for an autologous nerve graft.

• 대한소아치과학회지
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• 제7권1호
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• pp.85-93
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• 1980

This study was undertaken in order to observe the prevalence of congenital dental anomalies especially that of oligodontia and supernumerary teeth in 1024 children at age from 4 to 14 years, through history taking, oral examinations, roentgenographic observations of subjects, and statistic analysis was made. The following results were obtained: 1. The prevalence of oligodontia in 1024 children was $6.45{\pm}.8$ percent with a total of 122 teeth absent in sixty-six subjects, excluding 3rd molars, and most of children (86.4%) who have congenitally missing teeth showed abscence of one or two teeth individually. 2. The teeth most frequently absent were the mandibular second premolar, maxillary second premolar, maxillary lateral incisor, mandibular central incisor, and mandibular lateral incisor in order. 3. There was no statistically significant difference found in tooth abscence in the following comparisons; .Male vs Female .Bilateral vs Unilateral .Maxilla vs Mandible .Right vs Left 4. The prevalence of supernumerary teeth in 1024 children was $4.79{\pm}.67$ percent with a total of 59 supernumerary teeth in forty-nine subjects, all of children who have supernumerary teeth showed one or two supernumerary teeth individually. 5. Statistically significant difference was found in supernumerary teeth in the comparison of male vs female, and they were more frequent in male.

• 보건의료산업학회지
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• 제12권1호
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• pp.13-22
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• 2018

Objectives : This study examines the voluntary participation of the members of an organization who maintain cordial and friendly relationships with their colleagues, so that the human resources department within a hospital can be used efficiently. Methods : A total of 600 copies of the questionnaire were distributed, and 524 copies were returned (88%). Of these, 518 copies were used to verify statistic results using IBM SPSS and AMOS Ver. 22.0, including factor analysis, path analysis, mediating effects, and moderating effects. Results : The effect of organizational trust on organizational citizenship behavior has shown that OCBI (Interpersonal) is highly affected at large hospitals. However, the effect of organizational trust on OCBO (Organizational) is highly affected at small hospitals. Conclusions : The results of a gap analysis indicated that among the different aspects of organizational justice, distributive justice and interactional justice have a positive effect on organizational trust in small hospitals. The results also revealed that organizational trust and organizational citizenship behavior in small hospitals are more strongly affected than they are in large hospitals. As a result, job efficiency is improved in smaller hospitals.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.1033-1039
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• 2020

Vietnam is conducting an export-led growth model and labour-intensive industries contributing majorly to the total export value. In the context of Industry 4.0, the labour-based industries are significantly affected; hence, enhancing productivity is the key measure to maintain these industries. The garment industry contributes significantly to the total export value of Vietnam. Based on meta-frontier framework, the approach of data envelopment analysis is used to measure technical efficiency of Vietnamese garment firms and the global Malmquist TFP index is utilised to identify productivity change and its components including efficiency, technology and technical gaps between different groups of firms. The data of Vietnamese garment firms from 2013 to 2018 collected from the Vietnam General Statistic Office is used in this study. The results show that: (i) The total factor productivity of Vietnamese garment firms growth, technical progress is the main contributor; (ii) The private garment sector is the leading group; (iii) There is a large technological gap among Vietnamese garment sectors. The private and FDI garment firms have experienced a growth in all components of total factor productivity change. Meanwhile, technological progress change is the main reason to constrain the productivity growth of state-owned garment firms.

• 유통과학연구
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• 제20권9호
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• pp.47-59
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• 2022

Purpose: This study aims to analyze a triangulation model: 1) the effect of entrepreneurship education (EE) on entrepreneurship knowledge (EK) and entrepreneurship mindset (EM) and 2) the effect of EK on EM. Entrepreneurship education is a medium and pedagogical tool to cultivate EK and EM with the purpose enhancing of students who will be interested in entrepreneurial activities. Knowledge of adequate entrepreneurship is a stimulus strategic tool to develop the entrepreneurial mindset of students. Research design, data, and methodology: There were 278 respondents from Business and Non-Business both Indonesian and Malaysian students. The research design was quantitative and evaluated three hypotheses by PLS-SEM using WarpPLS v.7 software. Statistic descriptive for respondent used SPSS IBM v.26. Results: The results showed that the three hypotheses had supported with a significant level of p-value < 0.001. It's meant EE enhanced both EK and EM. Furthermore, increasing EM was not only by EE, but also EM could be increased through EK. Conclusions: The novelty of this research contributes to filling the knowledge gap in the development of pedagogy in the pursuit of entrepreneurship using a triangulation model of the relationship among EE, EK, and EM.

• 대한치과보철학회지
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• 제43권5호
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• pp.611-621
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• 2005

State of problem: Zirconia all-ceramic restoration fabricated with CAM system is on an increasing trend in dentistry. However, evaluation of the marginal and internal fits of zirconia bridge seldomly have been reported. Purpose: This study was to evaluate the at of margin and internal surface in posterior 3-unit zirconia bridge framework fabricated with CAM system(DeguDent, Germany). Material and Method: Preparations of secondary premolar and secondary molar on artificial resin model were performed for fabrication of 3-unit posterior bridge framework. Fits of 5 zirconia bridge framework were compared with 5 precious ceramo-metal alloy framework(V-GnathosPlus, Metalor, Switzerland), and prepared margins were designed to chamfer and shoulder finishing line. Each framework was cemented to epoxy resin model with reinforced glass ionomer(FujiCEM, GC Co., Japan), embedded in acrylic resin and sectioned in two planes, mesio-distal and buccolingual. Samples were divided into six pieces by sectioning and had two pieces of each surface(i.e mesial, distal, buccal and lingual surface) per abutment, so there were eight measuring points in each abutment. External gap was measured at the margin and internal gaps were measured at the margin, axial and occlusal surface. Gaps were observed under the measuring microscope(Compact measuring microscope STM5; Olympus, Japan) at a magnification of $\times100$. T-test were used to determine the statistic significance of the different gaps between zirconia and metal framework. Results and Conclusion: 1. External and internal marginal gaps of zirconia and metal framework were in clinically acceptable range. External marginal gaps were not different significantly between zirconia$(81.9{\mu}m)$ and metal $(81.3{\mu}m)$ framework and internal marginal gaps of zirconia $(44.6{\mu}m)$ were smaller than those of metal framework $(58.6{\mu}m)$. 2. Internal axial gaps of zirconia framework$(96.7{\mu}m)$ were larger than those of metal frame-work$(78.1{\mu}m)$ significantly and adversely, internal occlusal gaps of zirconia frame-work$(89.4{\mu}m)$ were smaller than those of metal framework $(104.9{\mu}m)$ significantly. 3. There were no significant differences in external and internal marginal gaps between chamfer and shoulder finish line when zirconia frameworks were fabricated.

• 대한치과보철학회지
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• 제40권6호
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• pp.545-559
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• 2002

There has been increasing use of IPS Empress $2^{(R)}$ owing to easy fabrication method, high esthetics similar to natural teeth, good marginal accuracy, and sufficient fracture strength. However, in clinical application, although a luting agent and the tooth cementation bonding procedure influence the marginal accuracy and fracture strength restoration, there has been a controversy in the selection of proper luting agent. This study was to measure the marginal fidelites and fracture strength of IPS Empress crowns according to three cement types, Protec $cem^{(R)}$, Variolink $II^{(R)}$ and Panavia $21^{(R)}$. After construction of 12 experimental dies for each group, IPS Empress $2^{(R)}$ crowns were fabricated and luted the metal master die prepartion of the maxillary right premolar. Marginal gaps before cementation and after cementation were measured. Buccal incline on the functional cusp of specimens were loaded until the catastrophic failure and fracture strength was measured. The results of this study were as follows: 1. The range of gap was $34.04{\pm}4.84{\mu}m$ before cementation and $37.88{\pm}5.00{\mu}m$ after cementation, which showed significant difference by paired t-test (p<0.05). The difference in the results from marginal accuracy according to measuring point proved to be not statistically significant by two-way ANOVA test (p>0.05). 2. The difference in the results from marginal accuracy according to three cement types Proved that The Variolink $II^{(R)}$ cement group had the least gap, $35.43{\pm}5.03{\mu}m$, and showed superior marginal accuracy while there existed statistic significance in Protec $cem^{(R)}$ cement group, $39.06{\pm}4.41{\mu}m$ or Panavia $21^{(R)}$ cement group, $39.16{\pm}4.39{\mu}m$ by two-way ANOVA test & multiple range test (p<0.05). 3. The difference in the results from fractures strength testing according to three cement type groups proved to be statistically significant (p<0.05). The Variolink $II^{(R)}$ cement group shows highest fracture strength of $1257.33{\pm}226.77N$, Panavia $21^{(R)}$ cement group has $1098.08{\pm}138.45N$, and Protec $cem^{(R)}$ cement group represents the lowest fracture strength of $926.75{\pm}115.75N$. 4. Three different cement groups of different components showed acceptable marginal fidelity and fracture strength. It is concluded that IPS Empress $2^{(R)}$ crowns luted using Variolink $II^{(R)}$ cement group had stronger fracture strength and smaller marginal gap than the other cement groups. Although Variolink $II^{(R)}$ resin cement seemed acceptable to clinical applications in IPS Empress $2^{(R)}$ system, the IPS Empress $2^{(R)}$ system still requires long-term research due to the lack of data in clinical applications.