• 한국정보통신학회논문지
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• 제19권6호
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• pp.1307-1312
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• 2015

스마트폰의 대중화에 따라 무선 데이터 트래픽이 기하급수적으로 증가하고 있으며, 이러한 데이터 트래픽을 원활히 수용하기 위하여 차세대 이동통신 네트워크에 대한 연구가 활발히 진행 중이다. 특히, 매크로 셀과 소형 셀을 활용하여 공간 재활용성을 높임으로써 네트워크 용량을 획기적으로 개선할 수 있는 이종 이동 통신망이 많은 관심을 끌고 있다. 이종 이동 통신망에서는 매크로 기지국과 소형 기지국 간의 송신전력의 차이로 인하여 부하 불균형과 간섭등의 문제가 발생하며, 이를 해결하기 위하여 cell range expansion (CRE) 기술을 활용한다. 본 논문에서는, 초밀집 이종 이동 통신망 에서 CRE bias (CREB)를 적응적으로 적용하는 새로운 셀 선택 방식을 제안하고 시스템 레벨 시뮬레이션을 통하여 셀 평균 전송률을 분석하고, 기존의 셀 선택 방식과 비교 한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.63-66
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• 2015

스마트폰의 대중화에 따라 무선 데이터 트래픽이 기하급수적으로 증가하고 있으며, 이러한 데이터 트래픽을 원활히 수용하기 위하여 차세대 이동통신 네트워크에 대한 연구가 활발히 진행 중이다. 특히, 매크로 셀과 소형 셀을 활용하여 공간 재활용성을 높임으로써 네트워크 용량을 획기적으로 개선할 수 있는 이종 이동 통신망이 많은 관심을 끌고 있다. 이종 이동 통신망에서는 매크로 기지국과 소형 기지국 간의 송신전력의 차이로 인하여 부하 불균형과 간섭 등의 문제가 발생하며, 이를 해결하기 위하여 cell range expansion (CRE) 기술을 활용한다. 본 논문에서는, 초밀집 이종 이동 통신망에서 CRE bias를 적응적으로 적용하는 새로운 셀 선택 방식을 제안하고 시스템 레벨 시뮬레이션을 통하여 셀 평균 전송률을 분석하고, 기존의 셀 선택 방식과 비교 한다.

• 한국학교보건학회지
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• 제29권3호
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• pp.149-155
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• 2016

Purpose: The purpose of this study was to identify the influence of cell phone addiction on communication skills and the interpersonal relationship ability of adolescents. Methods: The researcher recruited 751 high school students to assess their general characteristics, communication skills, cell phone addiction and interpersonal relationship ability. Data were collected from June 30 to July 14 in 2014 using copies of a structured self report questionnaire. The collected data were analyzed with descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and linear multiple regression using the SPSS/WIN 21.0 IBM program. Results: Of the students, 3.5% reported they were addicted users, and 7.6% reported they were heavy users. Results from multiple regression analysis showed that cell phone addiction did not have any influence on communication skills of the adolescents. However, cell phone addiction mostly affected the interpersonal relationship ability of the adolescents (${\beta}=.24$, p<.001). Poor school performance (${\beta}=.17$, p<.001) and low socioeconomic status (${\beta}=.12$, p<.05) were also related to the interpersonal skills of the adolescents. These variables explained 8.3% of the variance in the interpersonal skills of the adolescents. Conclusion: These results suggest that cell phone addiction has a negative influence on the development of the interpersonal relationship ability of adolescents. The findings of this study are expected to provide basic data about the influence of cell phone addiction on the interpersonal relationship ability of adolescents. Therefore, cell phone addiction treatment programs for adolescents need to include contents related to interpersonal relationship ability.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.252-256
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• 2001

The rapid development of communication equipment and information processing technology has led to a constant improvement in cordless communication. Lithium ion batteries used in cellular phones and laptop computers, in particular, have been in the forefront of the above revolution. These batteries use high value added raw materials and have a high and stable energy output and are increasingly coming into common use. The development of the material for the negative terminal has led to an improvement in the quality and efficiency of the batteries, whereas a reduction in the cost of the battery by researching new materials for the positive anode has become a research theme by itself. These long life batteries, it is being increasingly realized, can have value added to them by recycling. Research is increasingly being done on recycling the aluminum case and the load casing for the negative diode. This paper aims to introduce the current situation of recycling of lithium ion batteries. 1. Introduction 2. Various types of batteries and the situation of their recycling and the facts regarding recycling. 3. Example of cobalt recycling from waste Lithium ion secondary cell. 3-1) Flow Chart of Lithium ion battery recycling 3-2) Materials that make a lithium ion secondary cell. 3-3) Coarse grinding of Lithium ion secondary cell, and stabilization of current discharge 3-4) Burning 3-5) Grinding 3-6) Magnetic Separation 3-7) Dry sieving 3-8) Dry Classifying 3-9) Content Ratio of recycled cobalt parts 3-10) Summary of the Line used for the recovery of Cobalt from waste Lithium ion battery. 4. Conclusion.

• 한국인터넷방송통신학회논문지
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• 제21권6호
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• pp.57-63
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• 2021

긴급재난문자 서비스는 재난 상황에 대한 정보를 휴대폰으로 전달하는 공익 서비스이다. 휴대폰 보급률이 높은 대한민국은 긴급재난문자를 통한 재난정보 전달이 다른 정보 전달 방법 보다 높은 선호도를 갖고 있다. 하지만 문자로만 이루어져 있어 정보 취약 계층에게는 일반인들에 비해 재난정보 전달이 정상적으로 이루어지지 않고 있다. 이를 보완하기 위해서 긴급재난문자 서비스를 활용한 재난정보 전달 애플리케이션을 제안하고 연구를 진행하였다. 해당 논문과 같은 연구가 계속되어 향후 긴급재난문자는 국내외의 정보취약계층을 고려한 다양한 재난 관련 정보를 전송하는 서비스가 된다면 이를 통해 국민이 재난에 신속하고 정확한 대처를 통해 재난에 대한 피해를 감소시키는 효과를 제공할 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4593-4595
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• 2012

Introduction: Mobile learning enables users to interact with educational resources while in variable locations. Medical students in residency positions need to assimilate considerable knowledge besides their practical training and we therefore aimed to evaluate the impact of using short message service via cell phone as a learning tool in residents of Obstetrics and Gynecology in our hospital. Methods: We sent short messages including data about breast cancer to the cell phones of 25 residents of gynecology and obstetrics and asked them to study a well-designed booklet containing another set of information about the disease in the same period. The rate of learning derived from the two methods was compared by pre- and post-tests and self-satisfaction assessed by a relevant questionnaire at the end of the program. Results: The mobile learning method had a significantly better effect on learning and created more interest in the subject. Conclusion: Learning via receiving SMS can be an effective and appealing method of knowledge acquisition in higher levels of education.

• 한국정보시스템학회지:정보시스템연구
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• 제13권2호
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• pp.89-117
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• 2004

Mobile technologies and services have become one of the inevitable parts of people's lives and mobile businesses have also been widespread. Popular mobile internet services through cell phones have made people in the financial industry consider that 'mobile' is promising. Nevertheless, there have been little studies of mobile services in the financial industry and most of the studies have been concentrated on internet services. The main purpose of this study is to investigate on the determinants of intention to use mobile banking. To achieve the goal, based on the theoretical backgrounds of the Technology Acceptance Model(TAM). Survey questionnaires were distributed via post & email to 500 users who have been experiences with cell phone and have an account. Out of 291 responded questionnaires, 275 data sets were available for statistical analysis with SPSS 10.1. Research hypotheses are analyzed by LISREL 8.30. Factor analysis identified seven external factors : (1) convenience, (2) cost, (3) unusefulness, (4) riskiness, (5) personal innovativeness (6) users' self-efficacy (7) experience of mobile services. Results of this study show that convenience, unusefulness, riskiness, personal innovativeness and experience of mobile services have significant effects on intention to use mobile banking . Much of the previous researches have dealt with service provider only and have focused on mobile internet. In this regard, when it comes to a viewpoint that regards the mobile banking sector as a new sector of mobile businesses. This study may provide a guideline to activate of mobile banking acceptance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.218-223
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• 2008

Cell-phone becomes a necessary communication device in modern society. However, a paging signal by a sound transducer often acts as an unpleasant noise, thus necessitating a paging signal by a vibration motor. The conventional flat type vibration motor uses three-phase windings with three phase coils. In this article, a new design of a vibration motor using a V connection with two phase coils is presented, increasing mass productivity. For electromagnetic field analysis, due to the motor symmetry, two-dimensional modeling can be implemented for fast computation, and performance is predicted by the finite element method. The winding distribution angle turns out to be the most important design parameter for the elimination of dead points, and a new coil configuration is suggested which has no adverse effect on motor size and weight. Experimental tests of vibration confirm the validity of the proposed design.

• 패션비즈니스
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• 제17권6호
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• pp.88-97
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• 2013

'Smart Clothes', which incorporate topnotch digital technology into fashion, are a leading fashion runner in this digital era. The purpose of the study is to first help develop a practical design for outdoor backpacks which are equipped with eco-friendly solar cells that facilitate recharging diverse smart devices during outdoor activities; and, secondly, to offer some practical data from the actual appropriation tests that will be used for manufacturing such products. This trial study finds out how to conjoin some practical IT devices with fashion items and mainly focusses on designing outdoor backpacks which are loaded with solar cells for recharging electric devices, and, later, experiments on designed backpacks with some smart phones to see how it works. According to the desired purposes of backpacks, all the features can be adjusted and modified such as the kinds of solar cell panels, materials, sizes, positions of attachment, weights, etc. Smart Clothes are highly functional and fashionable items that satisfy both practical and emotional purposes, and are being actively developed to serve consumers. This study proves that Smart Clothes or Smart Wear will have practical uses for outdoor activities and will possibly lead our smart lifestyles.

• ETRI Journal
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• 제43권2호
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• pp.232-245
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• 2021

As wireless communication continues to develop in limited frequency resource environments, it is becoming important to identify the state of spectrum utilization and predict the amount needed in future. It is essential to collect reliable information for data analysis. This paper introduces a platform that enables the gathering of the scheduling information of a long-term evolution (LTE) cellular system without connecting to the network. A typical LTE terminal can confirm its assigned resource information using the configuration parameters delivered from a network. However, our platform receives and captures only the LTE signal over the air and then enables the estimation of the data relevant to scheduling for all terminals within an LTE cell. After extracting the control channel signal without loss from all LTE subframes, it detects valid downlink control information using the proposed algorithm, which is based on the error vector magnitude of depatterned symbols. We verify the reliability of the developed platform by comparing it with real data from mobile phones and service operators. The average difference in resource block utilization is only 0.28%.