Nanogenerators: Fully Rollable Transparent Nanogenerators Based on Graphene Electrodes (Adv. Mater. 19/2010)

Choi, Dukhyun,Choi, Min-Yeol,Choi, Won Mook,Shin, Hyeon-Jin,Park, Hyun-Kyu,Seo, Ju-Seok,Park, Jongbong,Yoon, Seon-Mi,Chae, Seung Jin,Lee, Young Hee,Kim, Sang-Woo,Choi, Jae-Young,Lee, Sang Yoon,Kim, Jo WILEY-VCH Verlag 2010 ADVANCED MATERIALS Vol.22 No.19

<B>Graphic Abstract</B> <P>The cover shows an image of fully rollable transparent nanogenerators synthesized using chemical vapor deposition grown large-scale graphene sheets as transparent electrodes and piezoelectric ZnO nanorod arrays. Sang-Woo Kim, Jae-Young Choi, and co-workers report on p. 2187 the electrical and structural stability of the nanogenerators, with excellent charge scavenging performance under external mechanical loads such as bending and rolling. This study shows that graphene-based nanogenerators are very promising for self-powered rollable transparent device applications. <img src='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content.gif' alt='wiley_img_2010/09359648-2010-22-19-ADMA201090066-content'> </P>

Consideration of Diluents Selection and Input Amounts of the Hunter Process for Tantalum Production

Jae‑Jin Sim,Sang‑Hoon Choi,Yong‑Kwan Lee,Sung Gue Heo,Taek‑Soo Kim,Seok‑Jun Seo,Kyoung‑Tae Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

Tantalum (Ta) is a heavy refractory metal with an atomic weight of 180.95 g/mol, a density of 16.6 g/cm3, and a high meltingpoint of 3017 °C. With its refractory characteristics, it shows excellent chemical and physical stability as well as corrosionand heat resistance at elevated temperatures. The demand for Ta metal and related compounds is increasing with the expansionof the electronics and chemical industries. The Hunter process was proven to be effective in producing Ta powder in1953. Hunter proposed a method in which potassium heptafluorotantalate (K2TaF7) was reduced by sodium (Na). Thus far,this process has been the primary commercial method to produce Ta powder. In this study, quantitative differences wereanalyzed for diluent selection. Additionally, consideration was given to changes in the caloric value depending on the inputamount of diluents. Finally, the optimum material input and the properties of the prepared Ta were analyzed. Stoichiometricratios of K2TaF7(1 mol), NaCl (6.2–6.7 mol), Na (5–7 mol) were weighed, to perform a metallothermic reduction reaction. After the reaction, the tantalum powder was recovered and the flush process was carried out. After that, it was dried in avacuum atmosphere. Physical properties such as oxygen concentration, PSA, ICP-OES, and XRD of powder were conductedto evaluate the characteristics of Ta powder that was finally manufactured.

A Study on Introduction to Private Investigation System and Direction Through Predicting Demand

Sung Gu Jo,Dong Jae Choi,Jeong hwan Park,Byeong Tae Kim 위기관리 이론과 실천 2014 Crisisonomy Vol.10 No.12

In Korea, private investigation business had been called as Heungsineop but it changed to messenger center from 1970s. Foreign private investigation agencies have started to run business as crisis management agency, consulting agency after Korea joined OECD in 1996. foreign private investigation agencies are still growing illegally by using similar names to private investigation business and today, these are covered doing illegal acting like shadowing, phone-tapping, even contract through media sources. Today, according to statistical data by the National Police Agency late 2012, messenger agencies are around 1574 in domestic and 939 of those are in the metropolitan area. Illegal types are uncovered as investigating personal life 27(68%), personal information offering 7(18%), location tracing 5(12%), illegal claim collection 1(2%) plus, clients for these company are uncovered as housewife 196(34%), company employee 152(27%), independent businessman 78(14%), profession 35(6%). Correctly present situation and dispersion of domestic private investigation businesses like security company because private investigation system has not been enacted in domestic, until now. Thus, this study try to analyze demand of private investigation for a proposal in legislation process which is pending in 19th assembly like Yun Jae-Ok's 「All Amendments Private Security Act」 and Song Young-Geun's 「Private Invstigation Act」 so we expect to that private investigation system is introduced to Korea as soon as possible.

The prediction of the tooth size in the mixed dentition for Korean

Moon, Sung-Hwan,Kim, Seong-Oh,Yu, Hyung-Seong,Choi, Byung-Jai,Choi, Hyung-Jun,Lee, Jae-Ho 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.2

이번 연구의 목적은 혼합치열기 아동에서 미맹출된 견치와 소구치의 크기를 예측하는데 있어서 한국인에 맞는 방정식을 만들기 위함이다. 미맹출 치아의 크기를 예측하는 것은 혼합치열기 교정 진단과 치료계획 수립에 있어서 매우 중요하다. 미맹출된 견치와 소구치 크기를 예측하는 방법은 몇가지가 있지만 그중에서도 가장 흔하게 쓰이는 것이 모이어의 예측표와 다나카와 존스턴의 방정식이 있다. 하지만 그것들은 백인을 위해서 제작된 것이고 치아 크기는 인종에 따라서 다르다고 알려져 있다. 이번 연구에서는 치아크기를 측정하여 하악 영구 절치의 크기 합과 견치 및 소구치의 크기 합 사이의 상관관계를 구하고 회귀방정식을 이용해서 한국인에 맞는 예측표를 만들었다. 연세대학교 치과대학에 재학중인 178명의 한국 학생(남 108명, 여 70명, 평균연령 21.63)을 대상으로 실험하였다. 영구치의 근원심 폭경을 석고모형상에서 calipers를 이용해서 측정하였다. 성별간의 치아 크기는 차이가 있었다(p<0.05). Correlation coefficient는 0.57에서 0.64의 범위였고, standard errors of the estimates 는 여성에서 0.6으로써 남성보다 우수하였다. r^(2)값은 0.27에서 0.41의 범위를 나타내었다. Estimating the size of unerupted teeth is an essential aspect of orthodontic diagnosis and treatment planning in the mixed dentition. Several methods were introduced and used for the prediction. The most common methods among these would be Moyers probability chart and Tanaka and Johnston equations. These are currently used widely, but they were developed for Caucasians. Because there are clear racial differences in teeth size, the objectives of this study were to produce correlation coefficients between the combined mesiodistal widths of the permanent mandibular incisors and those of the canines and premolars for each quadrant, and prediction tables with regression equations, specifically for Korean. 178 young adults (70 women, 108 men, mean age 21.63 years) were selected from the College of Dentistry, Yonsei University, Seoul, Korea. The mesiodistal crown diameters of the permanent teeth were measured with calipers. Significant sexual dimorphism was found in tooth sizes. The correlation coefficients between the total mesiodistal width of the mandibular permanent incisors and those of the maxillary and mandibular canines and premolars were found to be between 0.52 and 0.64. The standard error of the estimatation was better (0.60) for women and the r^(2) values ranged from 0.27 to 0.41 for both sexes, Prediction tables were prepared for Korean. This study showed larger canine and premolar diameters than Tanaka and Johnston's and Moyers' studies which might be due to the racial differences. Further investigations with a larger sample size will be needed for more representative data on the Korean population.

RFID 사용요인이 신뢰, 지각된 위험, 모바일RFID환경 하에서 사용의도에 미치는 영향 -약국RFID 시스템을 중심으로-

최재영 ( Jae Young Choi1 ),차재빈 ( Jae Bin Cha1 ),김상만 ( Sang Man Kim ) 경희대학교 경영연구원 2013 의료경영학연구 Vol.7 No.1

This study examined the influence of various factors of RFID use in mobile RFID environment, focusing on pharmacies` RFID systems. The purpose of the study was to verify the possibility of a more widespread use of RFID and mobile RFID in medical industry by exploring what impact RIFD use factors have on the intention to use in RFID environment. The subjects were pharmacists who have their own pharmacies in Seoul and Gyeonggi Province. Of 400 questionnaires distributed to the respondents, 392 were used in the final analysis except 8 with insufficient answers. The empirical analysis results showed that perceived security, perceived cost, and social influence had significant impacts on trust, while social influence and perceived cost had significant impacts on perceived risk. Among RFID use factors, social influence, perceived security, and perceived risk had significant impacts on intention to use in mobile RFID environment. Trust and perceived cost did not have a significant impact. The summary of analysis results, implications, and limitations are presented in the conclusion.

고속도로 IC 및 JCT 주변 유휴부지의 물류시설 활용가능성 분석 : 수도권 및 지방광역시를 중심으로

양현지(Yang, Hyun-Ji),최재성(Choi, Jae-Sung) 한국물류학회 2021 물류학회지 Vol.31 No.2

최근 코로나 19 등의 감염병으로 인한 비대면 활동 증가로 인터넷, 모바일 등을 통한 이커머스 택배 이용건수가 증가하며 택배업체 등의 물류시설 부지 확보 수요가 점점 증가하는 추세이다. 업체별로 필요한 부지를 연도별 임계치 수준에서 수급하며 적게는1천 평에서 많게는 1만 평 이상의 부지가 추가적으로 필요하므로 부족한 부지를 현재와 같이 부동산업체 등을 통해 사적영역에서확보하는 것은 지속가능성의 한계에 직면할 것으로 보인다. 본 연구에서는 수도권(서울, 인천, 경기도) 및 지방광역시(대전, 대구, 광주, 울산, 부산)를 중심으로 공공 부문의 도시계획시설 측면에서 가장 넓은 유휴부지의 확보가 가능한 고속도로 IC/JCT 교통광장 유휴부지의 부지현황⋅활용가능성을 분석하였다. 분석방법 및 내용으로 다음 카카오맵의 로드뷰, 스카이뷰 등을 활용해 연구대상지의 유휴부지를 전수조사 후 사업지 내 이면도로 등의 존재 유무에 따라 단기 및 중⋅장기적 사업 우선순위화 분류, 국가물류통합정보센터 내 물류단지 건립계획을 이용해 택배업체의 허브 및 서브터미널 건설 시 예상 사업비 분석, 한국은행의 산업연관표를 적용해 경제적 파급효과 등의 결과를 도출하였다. 도출된 유휴부지를 택배업체 등에서 활용하기 위해서는 IC/JCT 교통광장대부분의 지역이 현재 ｢국토계획법 시행령 제71조｣에 의해 생산⋅자연녹지 용도지역인 상황을 고려하면 ｢건축법 시행령 별표1｣ 의 ‘18.창고시설 중 물류터미널’을 추가하는 방안, ｢도로법｣내 교통광장의 설치 및 관리에 관한 규정을 신설하거나 박성중 의원등 10인이 제안하여 위원회 심사 중인 ｢도로공간의 입체개발에 관한 법률안｣의 본회의 통과를 통한 입법화를 완료해 법적 근거마련이 필요한 상황으로 보인다. 향후 법제도 개선을 통해 고속도로 IC/JCT의 유휴부지(총 183만평-수도권 140만평, 지방광역시43만평) 중 수도권은 약 12%, 지방광역시는 약 10% 정도만이라도 활용 가능하다면‘19년 한국통합물류협회의 18개 택배사업자가제시한 물류시설 구축을 위한 유휴부지 마련 수요를 충족시켜 부지확보의 어려움이 일정 부분 해소될 수 있을 것으로 추정한다. As contact-free activities have increased due to infectious diseases such as COVID-19, the number of delivery-related services has also increased through the rise of e-commerce. As such, the demand for securing sites for logistics facilities is rising as well. Each delivery company keeps supply and demand in balance at the annual threshold level, which means that they require additional land ranging from 3,300m2 (1,000 pyeong) to as much as 33,000m2 (10,000 pyeong). However, it is unreasonable to continuously secure land to meet demands from private areas through real estate companies, as is the current standard procedure done by delivery companies. This study analyzes the feasibility of securing unused land in its current state, focusing on unused sites in expressways IC/JCT, where the widest unused land, in terms of urban planning facilities can be found, mainly in the capital region (Seoul, Incheon, Gyeonggi-do) and provincial metropolitan cities (Daejeon, Daegu, Gwangju, Ulsan, Busan). Full-scale inspection of unused land near expressways is first conducted using Kakao Map’s Road View and Sky View, and the results, such as short-term or mid to long term business priorities, are derived depending on whether backside roads exist or not. Estimated business expenses are calculated using information of logistics center from the National Logistics Integrated Information Center, and economic effects of building hubs and sub-terminals for delivery companies in the unused land are also drawn, applying the Leontief input-output table from the Bank of Korea. Most unused land such as those surrounding roundabouts near expressways IC/JCT is considered as productive green areas and natural green areas in accordance with Article 71 of ｢Enforcement Decree of the National Land Planning and Utilization Act｣, so clause 18, which states “logistics terminal amongst storage facility field”, of schedule 1 in ｢Enforcement Decree of Building Act｣ should be added to the Article to loosen restriction on construction in areas surrounding roundabouts. Also, regulations on the installation and management of roundabouts in the ｢Road Act｣ should be established to allow delivery company to utilize the unused land derived through this analysis. Preparation of a legal basis is deemed necessary by passing legislation through the plenary session for ｢The Bill on the Development of Three-dimensional Road Space｣ under examination made by 10 lawmakers, including Park Sung-joong. If approximately 12% of the total unused land in expressways IC/JCT in the capital region and approximately 10% in provincial metropolitan cities are made available by improving the legal system in the future, demand of 18 delivery companies from Korea Logistics Association will be met. Through this, it is estimated that the difficulty of securing sites for logistics facility construction would be partially resolved.

Floristic characteristics of vascular plants and first distributional report of Pseudostellaria baekdusanensis M. Kim in Yongneup wetland protected area

Young-Chul Kim,Hyun-Hee Chae,Sang-Heock Oh,Seung-Ho Choi2,Moon-Pyo Hong3,Gi-Heum Nam,Jae-Yoon Choi,Hyun-Sook Choi,Kyu-Song Lee 한국환경생태학회 2015 한국환경생태학회지 Vol.29 No.2

Yongneup wetland protected area, the only high moor in Korea, is a core area to conserve biodiversity. Even though the Yongneup wetland protected area is relatively small, various plant species are distributed in the Yongneup wetland protected area because it includes various habitats showing different environmental gradients. Vascular plants distributed in the Yongneup wetland protected area were identified as a total of 376 taxa that is composed of 73 families, 217 genera, 322 species, 3 subspecies, 44 varieties and 7 forms. For endangered plants designated by the Ministry of Environment, 5 species including Trientalis europaea var. arctica, Lilium dauricum, Halenia corniculata, Lychnis wilfordii and Menyanthes trifoliata were found and 34 taxa were confirmed to be distributed only in the mountainous wetland habitats. Regarding naturalized plants, a total of 11 taxa were distributed, but most of them were distributed in the areas where artificial interference has occurred. And in areas inside the wetlands that are relatively well preserved, 2 species of Bidens frondosa and Erigeron annuus were observed. In this study, the occurrence and distribution of Pseudostellaria baekdusanensis M. Kim, which was recently found in Mt. Baekdu and reported as a new species, were identified in the Yongneup wetland protected area. A wetland is a very vulnerable area to drastic environmental changes and damages to its ecosystem could cause the extinction of rare plant species which are distributed only in the wetlands. Therefore, it is mandatory that current status of the Yongneup wetland protected area is evaluated and actions to prevent rapid environmental changes are taken. Fourteen separate investigations were conducted in 2013 and another four in 2014, to evaluate current status of the Yongneup wetland protected area. These investigations have provided us the basic information for future actions of conservation and restoration.

단상 유도형 동기 전동기(LSPM)의 특성해석에 관한 연구

정대성,김승주,이진헌,최재학,이주,Jung, Dae-Sung,Kim, Seung-Ju,Lee, Jin-Hun,Choi, Jae-Hak,Lee, Ju 한국조명전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.3

가전분야에서의 전동기 효율향상을 통한 에너지 소비절감 효과는 상당히 크지만 이를 위한 전동기의 설계/해석 기술 확보가 아직은 미흡한 상태이다. 이에 따라 유도형 동기전동기가 제안되었지만, 유도형 동기 전동기는 유도전동기와 통기전동기의 특성을 동시에 가지고 있어, 해석 및 설계가 쉽지 않다. 따라서 본 논문에서는 기존의 냉장고 압축기용 전동기인 단상유도전동기를 대처할 수 있는 단상 유도형 동기전동기를 이용해 파라미터에 따라 특성이 어떻게 바뀌는가에 대해 서술하였다. 그에 따라 단상유도전동기의 정상상태 특성을 해석하고 제안모델의 성능을 기존모델과 비교하고 실험하여 해석결과의 신뢰성을 검증한다. 또한 본 논문에서는 제안모델의 기존 고정자 형상이나 권선 스팩을 유지하고 회전자의 형상이나 구조만을 변경시켜 성능향상을 도모하였다. 해석방법으로는 전자장 수치 해석적인 방법으로 널리 이용되고 있는 유한요소법(Finite Element Method : FEM)을 이용하였다. Electric motor efficient improvement from home appliance field is important to the effect reducing the energy consumption. But the electric motor design/analysis technology is still insufficient. Specially the electric motor design/analysis technology of satisfying characteristic of both the induction motor and the synchronous motor such as Line start permanent motor. Therefore the electric motor design/analysis technology is urgently demanded reliability. This paper proposes the sing1e-phase line-start permanent magnet motor to develop the motor it with be able to alternate the sing-phase induction motor it is a refrigerator compressor motor. The sing-phase induction motor is analyzed in the steady state. And we have a certification test to compare our single-phase line-start permanent magnet motor with the sing-phase induction motor. In order to improve the performance, the stator of the single-phase line-start permanent magnet motor is same as the stator of the sing-phase induction motor and changes the rotor form and has the permanent magnet. It used the Finite Element Method(FEM) which is widely used with electronic-magnetic field numerical analysis method.

고해상도와 ROM 축소를 가지는 디지털 주파수 합성기의 설계 및 구현

이태호(Tae-ho Lee),최인규(Inㅡkyu Choi),최성혁(Sung-hyuk Choi),김재철(Jaeㅡchul Kim),심태은(Tae-eun Sim),박종식(Jong-sik Park) 한국통신학회 1999 한국통신학회 학술대회논문집 Vol.1999 No.11

Design and Implementation of Combined Channel Codec over IEEE 802.15.4a UWB PHY(ITC-CSCC 2009)

Jae-Young Choi,Dong-Sun Kim,Kyu-Yeul Wang,Sang-Seol Lee,Jae-Yeon Song,Duck Jin Jung 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7

In this paper, we present our implementation about the UWB PHY of IEEE 802.15.4a standard. It focuses on SECDED En/Decoder module for processing PHR Bits and RS En/Decoder module. They consist of two modules that operate independently of each other. We suggest that they process data bits through only RS En/Decoder module. RS En/Decoder module has PHR bits calculation together with RS operation. It also reduces the size of area because of processing PHR bits and RS data bits by using RS En/Decoder module register.