• Tribology and Lubricants
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• 제34권2호
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• pp.55-59
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• 2018

This paper proposes a new type of electro-mechanical wedge brake for commercial vehicles. The brake operates on a novel mechanism for self-boosting braking friction forces using eccentric shafts, and involves wedges that are inserted between the rampbridge and traverse; this self-boosting mechanism is explained herein. A dynamic analysis using ADAMS was conducted, and the findings are reported. The constraint and contact conditions are explained to verify the precision of the dynamic analysis. The dynamic analysis shows that in the proposed mechanism, the self-boosting effect occurs as desired. However, it is also noted that the system has a limitation in terms of the production of unlimited braking forces that can jam the roller inside the wedges. After demonstrating the self-boosting effect, dynamic analyses are performed for several values of the wedge angles and friction coefficients between the brake pads and disks. Conventionally, a lower wedge angle has been suggested owing to its provision of a larger clamping force for given friction coefficients. However, it is noted that lower wedge angles can lead to a higher probability of occurrence of undesirable high braking forces, which can jam the roller into the wedge; thus, a larger wedge angle is preferable for avoiding the undesirable jamming phenomena. These analysis results are presented and discussed herein.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.15-20
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• 2016

기존의 다중 모듈러스 기반 자기복원 등화 유형은 등화 초기에 적용되지 못하고 정상상태 성능 개선에 활용되었다. 본 논문에서는 다중 모듈러스를 원하는 응답으로 하는 유형의 자기복원 등화에서, 오차를 증강하여 오차의 역동성을 확장함으로써 초기 수렴 성능을 개선하고, 그 특성을 분석하였다. 제안 방법에서 오차 증강은 등화기 출력에 대한 심볼 판정에 비례하여 이루어진다. 아울러 제안 방법은 오차 역동성의 확장으로 인한 초기 수렴 기능을 갖기 때문에, 초기 수렴속도와 정상상태 오차 레벨에서 우수한 성능을 보인다. 특히 제안 방법은 등화의 전 과정을 하나의 알고리즘으로 진행하므로 기존의 다른 동작 모드로의 전환이나 선택 방법, 또는 다른 알고리즘과의 동시 동작 등이 불필요하다. 다중경로 전파와 부가 잡음이 있는 채널 조건하에서 이루어진 고차 신호점에 대한 자기복원 등화의 성능 분석 시뮬레이션을 통해 제안 방법의 유용성을 검증하였다.

• 전기전자학회논문지
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• 제25권4호
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• pp.778-781
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• 2021

본 논문에서는 SPICE를 사용한 16단 3D NAND Flash memory compact modeling을 제안한다. 동일한 structure와 simulation 조건에서 Down Coupling Phenomenon(DCP)과 Natural Local Self Boosting(NLSB)에 대한 channel potential을 Technology Computer Aided Design(TCAD) tool Atlas(Silvaco^TM)와 SPICE로 simulation하고 분석했다. 그 결과 두 현상에 대한 TCAD와 SPICE의 channel potential이 매우 유사한 것을 확인할 수 있었다. SPICE는 netlist를 통해 소자 structure를 직관적으로 확인할 수 있다. 또한, simulation 시간이 TCAD에 비해 짧게 소요된다. 그러므로 SPICE를 이용하여 3D NAND Flash memory의 효율적인 연구를 기대할 수 있다.

• 한국수소및신에너지학회논문집
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• 제24권6호
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• pp.573-579
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• 2013

Hydrogen engine with homogeneous charged compression ignition can achieve high efficiency by high compression ratio and rapid chemical reaction rates spatially. However, it needs to expansion of the operation range with over-all load conditions which is very narrow due to extremely high pressure rise rate. The adoption of the lean boosting in a HCCI $H_2$ engine is expected to be effective in expansion of operation range since minimum compression ratio for spontaneous ignition is decreased by low temperature combustion and increased surround in-cylinder pressure. In order to grasp its possibility by using lean boosting in the HCCI $H_2$ engine, compression ratio required for spontaneous ignition, expansion degree of the operation range and over-all engine performance are experimentally analyzed with the boosting pressure and supply energy. As the results, it is found that minimum compression ratio for spontaneous ignition is down to the compression ratio(${\varepsilon}$=19) of conventional diesel engine due to decreased self-ignition temperature, and operation range is extended to 170% in term of the equivalence ratio and 12 times in term of the supply energy than that of naturally aspirated type. Though indicated thermal efficiency is decreased by reduced compression ratio, it is over at least 46%.

• 대한가정학회지
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• 제49권10호
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• pp.71-79
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• 2011

When adolescents undergo the period of transition, they need to promote self-confidence from social support by parents, teachers or friends. It was believed that boosting subjective perception on their main areas of interest such as academic performance, appearance and fashion will result in happiness. The main purpose of this study was to investigate the influence of social support including family support, teacher support and friend support on self management, appearance satisfaction and fashion opinion leadership. A total of 412 questionnaires from the middle and high school students living in or near Seoul were collected and analyzed. The results indicated that teacher support and family support had a positive effect on self-management and family support had a positive effect on appearance satisfaction. Furthermore, friend support had a positive effect on fashion opinion leadership. In conclusion, implications for promoting self-confidence related to self-management, appearance satisfaction and fashion opinion leadership with the help of social support are suggested.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.335-341
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• 2014

Cancer is a menace fast gaining momentum in Nigeria and other developing countries. It is an expensive disease requiring a major financial and human resources for prevention, diagnosis and treatment. With no national policy on cancer control in the conntry, incidence (111.7/100,000 population) and mortality (86.6/100,000) rates in Nigeria are spiraling beyond control. This literature search study was primarily aimed at providing recommendations on cost-effective strategies for development interventions to promote self-management for cancer survivors in Nigeria with a goal to improve quality of life and overall survival.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.125-132
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• 2007

Within the framework of brake-by-wire technology, this paper presents five types of novel models of electro-mechanical disk brake calipers with self-servo mechanism which provides self-servo effect of boosting a friction force generated between the brake pad and the rotor disk surface. The models have been developed utilizing patent map analysis results of previous invents of electro-mechanical brake calipers. The feasibility of the developed motor-driven brake caliper models have been validated through the dynamic simulation analysis. Among the developed models, the caliper mechanism with separated pressure plate was designed especially in detail and was made as a pilot. The pilot caliper has been installed on the simple test bed constructed with domestic passenger car brake components, and its function and effectiveness have been validated through several types of experimental tests.

• 지식경영연구
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• 제18권4호
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• pp.261-286
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• 2017

Key factors enhancing transfer behavior of training and knowledge sharing are of great interest to researchers and executives because training transfer and knowledge sharing activities are remarkable predictors of organizational growth. This study investigates the core motivations for boosting transfer behavior of training and knowledge sharing. To empirically test the impacts of employee training, servant leadership and self-efficacy, a survey was conducted in small-medium sized companies. The data (N=292) were analyzed using structural equation modeling analysis. The results indicate that higher employee training positively leads to self-efficacy and transfer behavior of training. Servant leadership is positively leads to self-efficacy, transfer behavior of training, and knowledge sharing. Self-efficacy of employees induces greater transfer behavior of training and knowledge sharing. Finally, transfer behavior of training encourages workers to increase knowledge sharing. This study represents an initial step to examine the psychological mechanism of improving employees' transfer behavior of training and knowledge sharing activities based on the employee training qualities and servant leaderships.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.135-147
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• 2023

Internet of things has revolutionaries every field of life due to the use of artificial intelligence within Machine Learning. It is successfully being used for the study of Radiation monitoring, prediction of Ultraviolet and Electromagnetic rays. However, there is no particular system available that can monitor and detect waves. Therefore, the present study designed in which IOT enables intelligence system based on machine learning was developed for the prediction of the radiation and their effects of human beings. Moreover, a sensor based system was installed in order to detect harmful radiation present in the environment and this system has the ability to alert the humans within the range of danger zone with a buzz, so that humans can move to a safer place. Along with this automatic sensor system; a self-created dataset was also created in which sensor values were recorded. Furthermore, in order to study the outcomes of the effect of these rays researchers used Support Vector Machine, Gaussian Naïve Bayes, Decision Trees, Extra Trees, Bagging Classifier, Random Forests, Logistic Regression and Adaptive Boosting Classifier were used. To sum up the whole discussion it is stated the results give high accuracy and prove that the proposed system is reliable and accurate for the detection and monitoring of waves. Furthermore, for the prediction of outcome, Adaptive Boosting Classifier has shown the best accuracy of 81.77% as compared with other classifiers.

• 한국치위생학회지
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• 제12권2호
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• pp.327-334
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• 2012

Objectives : The purpose of this study was to examine the self-esteem and job-seeking efficacy of dental hygiene students in an attempt to provide some information on career guidance, counseling and the development of employment programs by colleges, as self-esteem seemed to be one of integral variables to affect job-seeking efficacy. Methods : The subjects in this study were the dental hygiene students in three different colleges in South and North Jeolla Provinces. After a self-administered survey was conducted, the answer sheets from 562 respondents were analyzed by the SPSS(Statistical Package for the Social Science) WIN 12.0. Results : 1. The students investigated got a mean of 2.43 in self-esteem, which was not a high score. The sophomores had a better self-esteem than the freshmen and juniors, and the gaps among the respondents in each subfactor of self-esteem were significant($p^*$ <0.01, $p^{**}$ <0.05). 2. The students got a mean of 3.12 in overall job-seeking efficacy, and there were significant differences among them in each subfactor of job-seeking efficacy($p^*$ <0.01). 3. The freshmen were ahead of the sophomores and juniors in job-seeking efficacy, and the gaps between the former and the latter were significant($p^*$ <0.01). 4. There was a significant relationship between the self-perceived self-esteem and job-seeking efficacy of the students. A higher self-esteem led to a better job-seeking efficacy(p<0.01). Conclusions : The above-mentioned findings illustrated that a higher self-esteem had a more positive effect on job-seeking efficacy. Therefore the development of programs geared toward boosting the self-esteem of dental hygiene students is required, and educational institutions should provide quality self-esteem programs for students to plan and prepare for their future, to make the right career choice, to improve their vocational adjustment, to keep pursuing self-development and to build the right values.