• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.6
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• pp.614-619
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• 2009

The STW(servo track writing) system which is the process of writing servo signals on disks before assembling in drives uses the spindle motor-chuck mechanism to realize low cost because the spindle motor-chuck mechanism has merit which can simultaneously write multi-disk by piling up disks in hub. Therefore, when the spindle motor-chuck mechanism of horizontal type operates in high rotation speed it is necessary to reduce the effect of RRO(repeatable run-out) and NRRO(non-repeatable run-out) to achieve the high precision accuracy of nano-meter level during the STW process. In this paper, we analyzed that the slip in assembly surfaces can be caused by the mechanical tolerance and clamping force in hub-chuck mechanism and can affect NRRO performance. We designed springs for centering and clamping considering centrifugal force by the rotation speed and assembly condition. The experimental result showed NRRO performance improves about 30 % than case of weak clamping force. The result shows that the optimal design of the spindle motor-chuck mechanism can effectively reduce the effect of NRRO and RRO in STW process.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.341-344
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• 2007

조선시대에 도성의 개천과 한강변에서 하천 수위를 측정하였다. 세종 23년(1441년)에 측우기와 수표(水標)를 제작하여 강우량과 하천수위를 측정하기 시작한 것이다. 수표는 지금의 청계천과 한강변두 곳에 설치하였다. 와다유찌는 조선고대의 관측기록을 정리하면서 측우기 기록을 분석하였고, 수표 기록을 정리하였다. 본 연구에서는 고문헌 자료에서 수표 관측 기록을 복원하여 조선의 도성인 개천(청계천)과 한강의 홍수 기록을 복원하는데 활용하고자 하였다. 본 연구에서 복원한 승정원일기와 기우제등록에 수록된 수표의 관측기록은 와다유찌가 조사한 기록을 상회한다. 와다유찌가 조사한 기록은 명종 1554년부터 영조 1778년까지인데, 1554년의 기록은 1회에 그치며, 인조11년(1633) 이후의 기록이 대부분이다. 이 점은 기우제등록의 경우도 유사하다. 기우제등록은 인조 11년부터 고종 26년(1889)까지의 기우제, 기청제, 기설제에 대한 기록을 정리한 것으로 전체 6권으로 구성되어 있다. 기우제 기록과 함께 수표기록(중부, 남부, 한강 및 수표)이 포함되어 있다. 기우제등록에 수록된 수표기록은 총 690회에 이르지만, 1779년 6월 11일의 3척 5촌을 마지막으로 더 이상의 기록은 찾아볼 수 없다. 숙종의 재위 기간에는 1669년부터 1791년까지 매년의 홍수상황이 기록되어 있다. 당시 한강의 수위와 도성안 개천에서 중부수표와 남부수표 2곳의 수표 기록을 있으나, 숙종 23년(1697)부터는 중부수표만 기록되어 있다. 이 지점에서의 10척을 상회하는 홍수는 20번의 기록이 있다.

• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.418-422
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• 2003

평판형 유도결합 플라즈마 식각장비(inductively coupled plasma etcher)를 이용하여 각종 공정조건들에 따른 GaAs의 식각특성을 연구하였다. 공정변수들은 ICP 소스파워(0-500 W), RIE 척파워(0-150 W), 가스 종류($BCl_3$, $BCl_3$/Ar, $BCl_3$/Ne) 및 가스혼합비였다. $BCl_3$ 가스만을 이용하여 GaAs를 식각한 경우보다 25%의 Ar이나 Ne같은 불활성 기체를 혼합한 $15BCl_3$/5Ar, $15BCl_3$/5Ne 가스를 이용한 경우의 식각률이 더 우수한 것을 확인하였다. 그리고 50% 이하의 Ar이 혼합된 $BCl_3$/Ar의 경우는 높은 식각률 (＞4,000 $\AA$/min)과 평탄한 표면(RMS roughness : ＜2 nm)을 얻을 수 있었지만 지나친 양(＞50%)의 Ar의 혼합은 오히려 표면을 거칠게 하거나 식각률을 떨어뜨리는 결과를 가져왔다. 그리고 20 sccm $BCl_3$, 100 W RIE 척파워, 300 W ICP 소스파워, 공정압력이 7.5 mTorr인 조건에서의 GaAs의 식각결과는 아주 우수한 특성(식각률: ∼ 4,000, $\AA$/min, 우수한 수직측벽도: ＞$87^{\circ}$, 평탄한 표면: RMS roughness : ∼0.6 nm)을 나타내었다.

• Journal of Family Resource Management and Policy Review
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• v.19 no.1
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• pp.1-21
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• 2015

Unlike daily hassles or minor stressors, immigration is an intense life event that may cause excessive stress. In particular, immigrant parents find themselves in a more stressful situation in that they experience stresses caused by immigration and stresses caused by parenting at the same time. The purpose of this study is to develop and validate an Immigrant Parental Stress Inventory (IPSI), that objectively and comprehensively assesses the stress experienced by immigrant parents within the Korean context. Based on the Immigrant Parental Stress Inventory developed within the American context, preliminary items were refined through a literature review and the discussions of experts and immigrant parents and were empirically validated with a sample of 203 immigrant parents residing in Korea. Through exploratory and confirmatory factor analysis, six main factors were identified (Factor1 Difficulties in communication, Factor2 Financial difficulties, Factor3 Difficulties in social adjustment, Factor4 Social discrimination, Factor5 Lack of social resources, Factor6 Difficulties in parenting). The IPSI was shown to be a psychometrically sound instrument that is capable of measuring immigrant parental stress within the Korean context. Social service professionals and researchers studying or working with immigrant families could use the IPSI to examine immigrant parental stress.

• The Research Journal of the Costume Culture
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• v.18 no.2
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• pp.348-370
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• 2010

The purpose of this study was to propose some plan which could satisfy consumer's expectation emotional needs by comparing emotional scale between fashion brand image and brand website coloration image. For this study, 12 brand websites within four fashion zone, men's clothing, women's clothing, casual wear, and sports wear were chosen. The questionnaires were comprised of 27 emotional adjectives which were selected from previous studies. The questionnaires were distributed to university students and office workers for 3 to 17 on September. Among them, 118 questionnaires were analyzed by SPSS tool. The qualitative analysis for emotional adjective sorting, content analysis for website color chip sorting, and quantitative analysis for consumers were used in this study. Some differences exist between brand image and website coloration band image as the result. As the numbers of internet user became larger, the costumer's emotional image which gives maximum satisfaction is getting more important in fashion brand website. Therefore, fashion website managers should satisfy consumers with functional and emotional needs.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.658-667
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• 2020

The purpose of this study was to develop the Servant Leadership Scale-Pastoral Version(SLS-P). In order to accomplish the purpose of this study, analyzed the relationships of Christian tradition and servant leadership, explored the rationale about servant leadership measurements and 366 of the Christians were sampled through the cluster sampling. The finding of the study were as follows: First, The characteristics of servant leadership analyzed in Bible traditions and Jesus model. Second, The factorial structure of PHS was extracted as 5 factors (sharing, serving, caring, humbling, leading) with 23 items. Third, The utilizations of this SLS-P expects to be evaluated to the servant leadership program in the pastoral setting.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.445-452
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• 2018

In a world where everything in life is being digitized, the amount of data is increasing exponentially. These data are processed into new data through collection and analysis. New data is used for a variety of purposes in hospitals, finance, and businesses. However, since existing data contains sensitive information of individuals, there is a fear of personal privacy exposure during collection and analysis. As a solution, there is privacy-preserving data mining (PPDM) technology. PPDM is a method of extracting useful information from data while preserving privacy. In this paper, we investigate PPDM and analyze various measures for evaluating the privacy and utility of data.

• Korean Journal of Child Studies
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• v.36 no.5
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• pp.95-113
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• 2015

This study aimed to develop and validate a scale which could be used to evaluate mathematical interactions of parents with their young children. The subjects comprised 408 mothers of 4-6-year-old children. Means, standard deviation, $x^2$, Cramer's V, exploratory factor analysis, confirmatory factor analysis, Pearson correlations, and Cronbach's ${\alpha}$ were calculated. First, 49 items were developed through a review of relevant research, parent interviews, confirmation of item adequacy and content validity. These items were then edited down to a final list of 24 items representing 4 factors identified by exploratory factor analysis. Second, this 24-item. 4-factor scale was shown to have adequate construct validity, norm validity, and reliability by confirmatory factor analysis, Pearson correlation analysis, Cronbach's ${\alpha}$. In conclusion, the final mathematical interaction scale for young children's parents was composed of 24 items with 4 factors: "interaction regarding numbers and operations, measurements, and patterns", "interaction regarding data collection and result presentation", "interaction with picture books", and "interaction regarding shapes and figures"

• Journal of Navigation and Port Research
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• v.26 no.5
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• pp.481-489
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• 2002

The purpose of this paper is to construct the model that enables to estimate the amount of tanker voyage charter by region or by ship size. This paper decomposed the mechanism of voyage and time charter step by step, and apply the accumulated date of KMI chartering database. The results of the estimation is that the amount of voyage charter in 2007 will be 25,751 or 23.3% increase compared with that of 2000. And the amount of voyage charter in Korea will be 9.3% of the world amount, and will be 26.6% of the Far East amount.

• The Journal of Korean Association of Computer Education
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• v.22 no.5
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• pp.67-77
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• 2019

The purpose of this study is to develop and validate a general-purpose evaluation tool and to analyze their applicability in problem solving programming education for college students of teacher training college. For this purpose, we have redefined the area of computational thinking and detail elements from the viewpoint of problem solving programming, and developed general-purpose computational thinking scale to evaluate them. The reliability and validity were analyzed by applying the evaluation tool developed for the actual college students of teacher training college. Through this study, it was confirmed that the a general-purpose evaluation tool developed in this study can be used as a tool to computational thinking assessment and can be generalized.