• Communications of Mathematical Education
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• v.21 no.2 s.30
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• pp.321-330
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• 2007

The purpose of this study is to develop a tool which can be used in factor analysis of inequality on mathematics education. The objectives for study are develop an index that can be used to find a deviation of objects on mathematics scholastic achievement. The results of this study are deviation index of objects on mathematics scholastic achievement which development can be applications to Gini coefficient.

• Journal of the Korean Data and Information Science Society
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• v.28 no.4
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• pp.733-742
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• 2017

There are many areas of applications where Gumbel distribution are employed such as environmental sciences, system reliability and hydrology. The goodness-of-fit test for Gumbel distribution is very important in environmental sciences, system reliability and hydrology data analysis. Therefore, we propose the two test statistics to test goodness-of-fit for the Gumbel distribution based on the generalized Lorenz curve. We compare the new test statistic with the Anderson - Darling test, Cramer - vonMises test, and modified Anderson - Darling test in terms of the power of the test through by Monte Carlo method. As a result, the new test statistics are more powerful than the other test statistics. Also, we propose new graphic method to goodness-of-fit test for the Gumbel distribution based on the generalized Lorenz curve.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.2813-2827
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• 2018

Progressive censoring schemes have become quite popular in reliability study. Under progressive censored data, however, some units can be failed between two points of observation with exact times of failure of these units unobserved. For example, loss may arise in life-testing experiments when the failure times of some units were not observed due to mechanical or experimental difficulties. Therefore, multiply progressive censoring scheme was introduced. So, we derives a maximum likelihood estimator of the parameter of exponential distribution. And we introduced the goodness-of-fit test statistics using order statistic and Lorenz curve. We carried out Monte Carlo simulation to compare the proposed test statistics. In addition, real data set have been analysed. In Weibull and chi-squared distributions, the test statistics using Lorenz curve are more powerful than test statistics using order statistics.

• The Korean Journal of Applied Statistics
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• v.23 no.4
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• pp.767-776
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• 2010

Frontier (1976) suggested a criterion based on the expected length of ordered random intervals under the Broken-stick model (Barton and David, 1956) to determine the optimal number of principal components retained. It is considered to be one of the methods that provide the most consistent simulation results (Jackson, 1993). This study is aimed to propose a method using the distribution of ordered random intervals to evaluate the contribution of principal components. We also examine several types of Gini indices along with the corresponding Lorenz curves to visualize the overall equivalence of those contributions.

• Journal of Digital Convergence
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• v.18 no.6
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• pp.33-44
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• 2020

The main objective of this study is to measure the concentration and deconcentration of the domestic freight forwarding system which illustrate the development trends in this industry. In this study, Herfindal-Hirschman index (HHI), shift-share analysis (SSA), and GINI coefficient combined with Lorenz curves were employed to investigate the domestic freight forwarders. The results are as follows: first, the HHI was used to assess the concentration of domestic freight forwarders in Vietnam. The downward trend from 0.117 in 2008 to 0.083 in 2018 indicate the deconcentration of domestic freight forwarders in Vietnam. Second, the SSA results indicated that the company Transimex showed the best performance with a shift effect of million VND 1,906,515 and a ABSGR value of million VND 2,158,232. Third, the GINI index go down from 0.468 to 0.393 in 2008-2018 as follow and the Lorenz curves covered a large part which make more demonstrate the deconcentration trend of freight forwarding in Vietnam. The results show that deconcentration is a trend in 2008-2018. The results of this study provides relevant data on freight forwarders which are not easily accessible to related stakeholders.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.476-483
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• 2006

This study tried to estimate the concentration indices of 15 forested national parks using Gini coefficient and Lorenz curve which can be measure the degree of inequality. The concentration indices were estimated by two parts which are yearly index for the periods of 1997-2005 and travel origin area(city or province) distribution index each national park. The empirical results were as follows: first, yearly Gini coefficients showed severe inequality. Particularly, 2004 and 2005 Gini coefficients were .453 and .446. which are intensive inequality compared with other years. Second, in travel origin area distribution each national park, Gini coefficients of Bukhansan and Kyeryungsan national park were .916 and .855 which are the great inequality compared with other national parks. The other hand, Gini coefficients of Dukyusan and Byunsanbando national parks were .508 and .628 which are the lowest inequality. The national park policy manager should find out the factors of concentration and deconcentration each year and national park and decided the visitor distribution policy which visitor size and scope for balancing the natural resources use.

• Journal of the Korean Institute of Rural Architecture
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• v.13 no.4
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• pp.59-66
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• 2011

This study aims to understand the degree of inequality of surveyed rural amenity resources according to resources and region in basic self governing body by estimating the Gini Coefficient and Lorenz Curve. Case Study was performed in Sunchang basic self governing body which full survey of rural amenity resources was completed. The Gini Coefficient was applied to measure the concentration of amenity resources in 11 Eup-Myun regions, Sunchang county of Jeonbuk province. The results demonstrate significantly different variation according to Eup-Myun regions and amenity variables. This result would be used as a basic data for rational rural planning based on amenity resources through identifying distributional concentration of rural amenity resources in basic self governing body.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.441-441
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• 2010

Hyperthermal neutral beam (HNB)은 박막 성장에 필요한 에너지와 반응 입자들을 동시에 공급할 수 있기 때문에 특히, 저온에서 박막을 성장시킬 때 매우 유용하다. 이와 같은 목적으로 race track 형태의 자기장 구조를 갖고 있는 2.45 GHz electron cyclotron resonance (ECR) plasma를 이용한 HNB 소스를 개발하였다. HNB 소스에서 인출되는 입자들은 중성 입자 뿐만 아니라 이온이나 전자와 같은 하전 입자들로 구성되어 있다. 그러나 양질의 HNB를 얻기 위해서는 하전 입자들의 구성 비율을 최소화해야 한다. HNB 소스는 하전 입자의 구성 비율을 1 % ($1{\mu}A/cm^2$) 이하가 되도록 설계되었다. 이것을 위해서 영구 자석의 자기장을 이용한 plasma limiter를 설계하였다. 대부분의 전자는 limiter 앞에 형성된 자기장의 구조와 반응하여 주로 gradient B drift와 curvature drift를 통하여 차단되고, 이온은 로렌츠 힘을 받아 빔 축으로 부터 벗어나도록 하였다. Limiter의 특성을 연구하기 위해서 정전탐침을 limiter에서 빔 축 방향으로 이동시키면서 I-V 곡선과 이온 포화 전류 및 전자 포화 전류를 측정하였다. 측정 결과를 바탕으로 plasma limiter의 성능을 검증하였고 문제점을 논의하였다.

• Journal of Environmental Policy
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• v.10 no.2
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• pp.21-44
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• 2011

It is important to consider an equitable allocation framework for domestic GHG emission reduction. First, the study established criteria and indicators for the National Allocation Plan (NAP) based on the principles of cost-efficiency and social-acceptance, and performed a case study of the sectoral effort sharing method, using the effort sharing index. The equity analysis of effort sharing based on sectoral preferences and inter-sectoral equity using a Lorenz Curve are performed. The equitable method is more likely to be suitable than the economic one which considers just reduction potential. Equitable effort sharing reflects a higher level of equity than economic effort sharing. At the same time, the equitable effort sharing method is essential for reflecting equity and establishing criteria for equity because evaluation with the equitable effort sharing method depends in particular on the weight of equity criteria. The result suggests the importance of consideration of equity and the establishment of equity criteria. In conclusion, it is critical to consider not only cost-efficiency but equity in policy decision making in terms of the sectoral effort sharing for national GHG reduction target.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.1
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• pp.11-19
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• 2008

This paper proposes small VCM(voice coil motor) type, auto-focusing and zoom actuators for mobile information devices. In order to meet the large output displacement within small height restriction, the proposed auto-focusing actuator adopts curved suspensions, which are similar to a leaf-spring type suspension of optical disk drives. The sensitivity of design parameters on output displacement and dynamic performance is implemented using ANSYS (3D FEM tool) to determine the optimal geometry and stiffness of the curved suspensions. This paper also investigates a new zoom actuator without a suspension supporting a bobbin. The zoom actuator uses a moving rail and a stoper mechanism by generating rotational force at lens holder. Magnetic flux density of the zoom actuator are calculated by both the FEM and permeance method. Experiments using prototypes of the proposed focusing and zoom models show that both actuators meet the required displacement and performance.