Planetary milling에 의한 $TiN_x$의 제조

김성진,김동식,라노,박성범,권원일,김문협,우흥식,안중호,Kim, Sung-Jin,Kim, Dong-Sik,Rahno, Khamidova,Park, Sung-Bum,Gwon, Won-Il,Kim, Moon-Hyup,Woo, Heung-Sik,Ahn, Joong-Ho 한국결정성장학회 2005 한국결정성장학회지 Vol.15 No.3

[ $TiN_x$ ] powder have been fabrication by making of reaction between titanium powder and $Si_3N_4$ bowl during a planetary milling. Milling times were maintained for 1 hour, 5 hours, and 10 hours, respectively. The XRD result showed existence of non-stoichiometric compound of $TiN_{0.26}$ after 5 hours milling and coexistence of TiN with $TiN_{0.26}$ after 10 hours milling. Particle size distribution was investigated by particle size analyzer and microstructure was analyzed by FE-SEM. The size of titanium was decreased with increasing the milling time and the mean size of $TiN_x$ after 10 hours milling was increased by 200 nm. Planetary milling법을 사용하여 Ti 분말과 $Si_3N_4$ bowl과의 반응을 유도하여 $TiN_x$을 제조하였으며, 이때 milling 시간은 1시간, 5시간, 10시간으로 조정하였다. 시편의 물성평가는 X선 회절분석을 통해 결정상의 변화를 분석한 결과 milling 시간이 5시간이 되면 비화학당량적 화합물인 $TiN_{0.26}$가 먼저 생성되고 10시간의 milling에서는 $TiN_{0.26}$과 TiN이 혼재되어 있는 것으로 확인되었다. 입도분석 및 FE-SEM으로 미세구조 분석을 한 결과, milling 시간이 증가함에 따라 Ti 입자사이즈가 감소하는 것으로 나타났으며, 10시간의 milling에서는 평균사이즈가 200nm의 $TiN_x$를 제조할 수 있었다.

한방의료이용 행태와 이에 영향을 미치는 요인 분석

김성진,남철현,김재돈,김병화,김기열,Kim Sung-Jin,Nam Chul-Hyun,Kim Jae-Don,Kim Byoung-Ha,Kim Gi-Yeol 대한예방한의학회 2004 대한예방한의학회지 Vol.8 No.1

This study was conducted to analyze community residents' behavior of Oriental medicine utilization and its related factors in order to provide basic data for formulation of policies on Oriental medicine. The subjects of this study was 500 residents who lived in big or medium sized cities and towns or villages Data were collected from March, 2002 to June, 2002. The results of this study can be summarized as follows. 1) According to socio-demographic characteristics of the respondents, female was 50.3%; 'over 50 years old' 29.9%, 'over college graduate' 39.7%, 'housewife' 23.0%, 'having spouse' 62.1%, 'Buddhist' 50.8%, 'living in big cities' 59.0%, 'middle economic class' 88.1%. 2) The highest proportion of frequency of Oriental medicine utilization was over 10 times(32.5%). The respondents visited Oriental medicine institutions for taking invigorant(51.1%), treatment of diseases in muscle or bone system(30.8%), treatment of diseases in digestive system(6.3%), etc. 3) According to the reasons of utilizing Oriental medicine, the proportion of good effect was highest(36.3%). 66.8% of the respondents replied that Oriental medical fee was expensive, while 0.8% of them replied that it was not expensive. 33.3% of them thought it was proper. 4) 35.5% of the respondents replied that treatment by Oriental medicine could cause side effect and 40.3% of them replied that the side effect could be caused by taking herb medicine. 5) 62.8% of the respondents replied that they would continuously receive opinions on Oriental medicine. The score of knowledge level of treatment by Oriental medicine $6.25{\pm}2.82$ points on the basis of 14 points. 6) The variables significantly influencing utilization of Oriental medicine includes taking diseases, living in big cities, male, upper (economic class, having religion, and effect of Oriental medicine. 7) The factors affecting effect of herb medicine were effect of treatment by Oriental medicine, marital status, knowledge level of Oriental medicine, having diseases, and frequency of receiving the treatment.

한국 어린이의 골 성숙도와 치아 석회화 단계 간의 상관관계

김성진,송제선,김익환,김성오,최형준,Kim, Seong Jin,Song, Je Seon,Kim, Ik-Hwan,Kim, Seong-Oh,Choi, Hyung-Jun 대한소아치과학회 2021 大韓小兒齒科學會誌 Vol.48 No.3

이 연구의 목적은 한국 아동의 골 성숙 단계와 여러 치아들의 석회화 단계 간의 상관관계를 알아보고자 하는 것이다. 만 6 - 14세의 남아 359명, 여아 384명의 수완부 방사선사진, 측방두부규격 방사선사진, 파노라마 방사선사진을 분석하여 평가하였다. 하악 좌측의 7개 영구치의 치아 석회화 단계는 Demirjian이 제시한 방법에 의해 평가되었다. 골 성숙도 단계를 평가하기 위하여 수완부 방사선 사진은 Fishman이 제시한 skeletal maturity indicators(SMI)에 따라 평가되었고, 측방두부규격 방사선사진은 Baccetti가 제시한 cervical vertebral maturation(CVM) 방법에 따라 평가되었다. Spearman의 순위상관분석을 시행한 결과 치아 석회화 단계와 골 성숙도 간에 유의미하게 높은 상관관계가 나타났다(r = 0.40-0.84, p < 0.001). 7개의 영구치 중에서 하악 제2대구치가 골 성숙도와 가장 높은 상관관계를 보인 반면 중절치가 가장 낮은 상관관계를 나타내었다. 남녀 모두에서 하악 견치의 stage G와 하악 제2대구치의 stage F가 SMI 6단계와 CS 3단계에서 나타날 확률이 가장 높았다. 이 연구의 결과에 따르면 치아 성숙도와 골 성숙도 사이에 높은 상관관계가 있으므로, 파노라마 방사선사진에서의 치아 성숙도 평가는 성장기 아동의 골 성숙도를 평가하는 보조적 수단으로 활용될 수 있다. The aim of this study was to investigate the relationships between the stages of calcification of various teeth and skeletal maturity stages among Korean subjects. The samples were derived from hand-wrist, panoramic radiographs, and lateral cephalograms of 743 subjects (359 males and 384 females) with ages ranging from 6 to 14 years. Calcification of seven permanent mandibular teeth on the left side were rated according to the system of Demirjian. To evaluate the stage of skeletal maturation, hand-wrist radiographs were analyzed by skeletal maturity indicators (SMI) system of Fishman and lateral cephalograms by cervical vertebral maturation (CVM) method of Baccetti. Statistically significant relationships were found between dental calcification and skeletal maturity stages according to Spearman rank-order correlation coefficients (r = 0.40-0.84, p < 0.001). The second molar showed the highest correlation and central incisor showed the lowest correlation for female and male subjects. For both sexes, canine stage G and second molar stage F were related to SMI 6 and CS 3. Because of the high correlation coefficients, this study suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period in Korean patients.

Comparison of the Structural, Magnetic, Electronic, and Optical Properties for ZnCoO and Co-precipitation Samples

김성진,조용찬,김수재,이승훈,정세영,배종성,정일경,Won-Kyung Kim,조채용,박성균 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.4

In order to investigate the ferromagnetism of Co-doped ZnO, we systematically fabricated Zn1−xCoxO (x = 0, 0.05, 0.1, 0.2, 0.4) thin films on (0001) Al2O3 substrates by rf-sputtering and measured their structural, electronic, optical, and magnetic properties. Below 20 mol% of Co, the Co ion could be successfully substituted at Zn site and showed clear paramagnetism in superconducting quantum interference devices (SQUID) and magnetic circular dichroism (MCD)measurements. However, secondary phases, including Co metal clustering, were found in the ZnO matrix at a 40-mol% Co concentration, showing a strong ferromagnetism due to the contributes of microscopic precipitates of Co ions. Consequently, the clear paramagnetic behaviors of all the fabricated ZnCoO thin films in the magneto-optic MCD results revealed that the spin-polarized band structure, an intrinsic property of ferromagnetism diluted ferromagnetic semiconductors (DMSs),could not be induced by the substituted Co ions themselves. Importantly, these results indicate that any intrinsic ferromagnetism in ZnCoO cannot be induced without the contribution of hydrogen.

SEED 기반의 부분 암호화 기법을 이용한 RFID 백워드 채널 보호 기법

김성진,박석천,Kim, Sung-Jin,Park, Seok-Cheon 한국정보통신학회 2008 한국정보통신학회논문지 Vol.12 No.1

본 논문에서는 기존 RFID 보안 기법에서 나타나는 도청으로 인한 정보 유출 문제를 분석하고 이를 해결하기 위하여 RFID에 SEED 보안 알고리즘을 응용한 부분 라운드 및 부분 암호화 기법을 적용하고자 한다. 기존에 제시된 많은 태그보안 기법들이 있으나, 보안과 구현의 문제에서 아직 현실적인 접근이 미비한 실정이다. 따라서, 본 논문을 통해 보다 현실적인 구현의 관점에서 하나의 아이디어를 제공하고, SEED기반의 비밀키 기반 암호화 알고리즘 기법을 적용하여 태그에서 리드간의 전송 취약구간인 백워드 채널상의 정보보안을 해결책을 제시하였다. In this paper, we analyse eavesdrop problem of existing RFID security scheme and proposed improved SEEB algorithm for RFID security. we suggest partial round process and security in SEED algorithm. Existing scheme has vulnerability of security and implementation so far from realization. Therefore In our paper, we proposed new scheme using modified SEED algorithm for backward channel protection.

급속 열처리 방법에 의한 Al-doped Zinc Oxide (AZO) Films의 제조 및 특성 평가

김성진,최균,최세영,Kim, Sung-Jin,Choi, Kyoon,Choi, Se-Young 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.7

In this study, transparent conducting Al-doped Zinc Oxide (AZO) films with a thickness of 150 nm were prepared on corning glass substrate by the RF magnetron sputtering with using a Al-doped zinc oxide (AZO), ($Al_2O_3$: 2 wt%) target at room temperature. This study investigated the effect of rapid thermal annealing temperature and oxygen ambient on structural, electrical and optical properties of Al-doped zinc oxide (AZO) thin films. The films were annealed at temperatures ranging from 400 to $700^{\circ}C$ by using Rapid thermal equipment in oxygen ambient. The effect of RTA treatment on the structural properties were studied by x-ray diffraction and atomic force microscopy. It is observed that the Al-doped zinc oxide (AZO) thin film annealed at $500^{\circ}C$ at 5 minute oxygen ambient gas reveals the strongest XRD emission intensity and narrowest full width at half maximum among the temperature studied. The enhanced UV emission from the film annealed at $500^{\circ}C$ at 5 minute oxygen ambient gas is attributed to the improved crystalline quality of Al-doped zinc oxide (AZO) thin film due to the effective relaxation of residual compressive stress and achieving maximum grain size.

손가락 비율을 이용한 장애인 특성

김성진,신현욱,이병순,최지원,최경호,Kim, Sung-Jin,Shin, Hyun-Uk,Lee, Byong-Sun,Choi, Ji-Won,Choi, Kyounh-Ho 한국데이터정보과학회 2012 한국데이터정보과학회지 Vol.23 No.6

태아기의 성 호르몬의 차이가 두 번째 손가락과 네 번째 손가락 길이의 비율을 비롯하여 여러가지 생리적 특성에 영향을 미칠 수 있다는 연구가 발표된 이후 관련 연구가 많이 진행되어 오고 있다. 그러나 우리나라 장애인을 대상으로 한 연구는 드물다. 이에 본 연구에서는 우리나라 장애인과 일반학생을 대상으로 손가락 비율 비교 및 장애인의 특성을 실증적으로 분석해 보았다. 그 결과, 장애인과 일반학생 모두에 있어 남자의 손가락 검지와 약지 길이 비율이 여자보다 낮아, 남녀별 성차가 있다는 일반적 사실을 확인 할 수 있었다. 다음으로, 남자와 여자 장애인 모두에서 나이대별 손가락 길이 비율은 통계적으로 유의한 차이가 없는 것으로 나타나, 일반인과 마찬가지로 장애인도 성장과정에서 검지와 약지 길이 비율이 크게 변하지 않음을 알 수 있었다. 마지막으로, 남자와 여자 지적 장애인 모두에 대하여 장애등급별 손가락 길이 비율도 통계적으로 유의하지 않은 것으로 나타난 바, 이로부터 손가락 검지와 약지 길이 비율이 장애여부와 관계가 있다는 점에 근거하면 현재의 장애등급 구분은 문제가 있다고 하겠다. Recent research has been mostly focused on the differences of prenatal sex hormone could affect the ratio of the lengths of the second to fourth digits (2D:4D) as well as the rate of several physiological characteristics. It has been suggested that digit ratios are thought to be associated with either higher prenatal testosterone levels or greater sensitivity to androgens, or both. However, a study of person with disabilities are rare in Korea. The purpose of this study was to compare patterns of the ratio (2D:4D) of the lengths of the second and fourth digits in persons with disabilities and students without disabilities. Also, we empirically analyze the characteristics of persons with disabilities. We found that finger length ratio (2D:4D) of men with disabilities and student without disabilities were lower than women with disabilities and student without disabilities. Therefore, it could be confirmed that finger length ratio (2D:4D) is sexually dimorphic trait. There were no correlations between finger length ratio (2D:4D) and age group in persons with disabilities. Therefore, as with person without disabilities, the 2D:4D ratio was negatively associated with a growth process of persons with disabilities. Finally, There was no difference correlations between finger length ratio (2D:4D) and level of disability in persons with intellectual disabilities. From this, one possible explanation for this is that if finger length ratio (2D:4D) is related to person with disability then current classification of the level of disability deserves further investigation.

실란 바인더에 의한 탄소나노튜브 박막의 감습 특성 변화

김성진,Kim, Seong-Jeen 한국전기전자재료학회 2010 전기전자재료학회논문지 Vol.23 No.10

Recently the solution-based thin film technology has often been treated in the field of device fabrication owing to easy process and convenience for the development of various semiconductor devices and sensors. We deposited on glass substrate single-walled carbon nanotubes (SWNTs)/silane hybrid thin films by multiple spray-coating which is one of solution-based processes, and examined their electrical response for humidity. Generally silane binders which are often mixed in carbon nanotube (CNT) solution to adhere CNTs to substrate well form easily each own functionalized group on the surface of CNTs after they are hardened by way of the hydrolysis reaction. In this work, we investigated how silane binders (TEOS (tetraethoxy silane), MTMS (methyltrimethoxysilane) and VTMS (vinyltrimethoxysilane)) in CNT thin films make effect to their electrical response on humidity. As the result, we found that the resistance in the samples using TEOS was changed dramatically while it was almost invariant in the samples using MTMS and VTMS for increasing humidity.

다공질 실리콘 층을 이용한 정전용량형 알코올 센서

김성진,Kim, Seong-Jeen 대한전자공학회 1999 電子工學會論文誌, D Vol.d36 No.9

A capacitance-type sensor using porous silicon layer is developed to measure aqueous alcohol concentration. Since alcohol, so called ethanol, is very permeable into the silicon wafer, it is often used to help chemical reaction when the silicon wafer is processed under some aqueous solution. In this work, the sensing property was measured for the alcohol concentration from zero to near 100 percent with two types of samples with porous silicon layer formed in 25 and 35% HF solution, respectively. Good reliability as well as fast response time and good linearity were shown over 10kHz and the measured capacitance was observed to be inverse to alcohol concentration due to the decrease of the whole dielectric constant in porous silicon layer. 다공질 실리콘 층을 이용한 정전용량형 알코올 센서를 제조하여 수용액 상태의 알코올(혹은 에탄올) 농도를 측정하고 그 특성을 평가하였다. 알코올 중에서 술의 주성분인 에탄올은 실리콘 웨이퍼에 대해 침투성이 강하여 수용액 내에서 실리콘 웨이퍼를 가공할 때 반응을 촉진시키는 물질로서 자주 사용된다. 본 연구에서는 각각 25와 35%의 불화수소용액에서 만든 다공질 실리콘 층을 알코올 감지막으로 한 알코올 센서를 제작하여 0%에서 100%의 알코올 농도범위에 대해 감지 특성을 측정하였다. 그 결과, 100kHz 이상의 인가 주파수에 대해 빠른 응답속도 및 선형성 뿐만 아니라 양호한 재현성이 관측되었으며, 측정된 정전용량은 수용액 속의 알코올 농도가 증가할 때 다공질 실리콘 층의 전체 유전 상수가 감소하게 되어 반비례하는 관계가 관측되었다.

MQTT Broker에서 우선순위에 따른 메시지 처리를 위한 방법에 관한 연구

김성진,오창헌,Kim, Sung-jin,Oh, Chang-heon 한국정보통신학회 2017 한국정보통신학회논문지 Vol.21 No.7

최근 IoT는 제한된 네트워크 환경에서의 디바이스 통신을 충족시키기 위해 경량화 프로토콜에 대한 연구가 진행중이다. MQTT는 대표적인 경량화 프로토콜이며, 오버헤드를 최소화하기 위해 작은 고정 헤더를 지원하고, publish/subscribe구조를 채택함으로써 실시간성을 보장한다. 하지만 MQTT는 중요 데이터에 대한 우선순위 처리를 지원하지 않아 특정 IoT 서비스에서의 QoS를 제공할 수 없다. 본 논문에서는 MQTT에서 다양한 IoT 서비스의 우선 순위를 고려하기 위한 메시지 처리 방법을 제안한다. 제안하는 방법은 노드에서 MQTT의 고정헤더에 우선순위 플래그를 추가하여 메시지를 전송하며, broker에서는 해당 메시지에 대한 우선순위를 확인하여 우선적으로 처리한다. 실험 및 평가를 통해 우선순위에 따라 노드간의 종단 간 지연의 감소를 확인하였다. Recently, IoT has been studying a lightweight protocol to satisfy device communication in a limited network environment. MQTT is a typical lightweight protocol. It supports small fixed headers to minimize overhead, and adopts publish/subscribe structure to guarantee real-time performance. However, MQTT does not support prioritization of important data and can not provide QoS in a specific IoT service. In this paper, we propose a message processing method to consider the priority of various IoT services in MQTT. In the proposed method, the priority flag is added to the fixed header of the MQTT in the node to transmit the message, and the broker confirms the priority of the corresponding message and processes it preferentially. Through experiment and evaluation, we confirmed the reduction of end-to-end delay between nodes according to priority.