서로다른 APF 제재의 적용시간에 따른 법랑질내 불소 흡수량 및 우식 억제효과에 관한 비교 연구

권순원,김용기 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.2

The purpose of this study was to compare the enamel fluoride uptake and anticariogenic effect following topical application with different physical form of fluoride and application time. The results can be summarized as follows: 1.While the 4-minite application increased the enamel fluoride uptake significantly than 1-minite application regarded of physical form of applied topical fluoride agents,no significant difference could be found between foam and gel type when applied for the identical period of time. 2.The application time or the physical form of topical agents had no significant influence on the reduction of caries lesion. 3.Based upon the above-mentioned results of this study,it cannot be concluded that the amount of enamel fluoride uptake has an absolute impact on the change of lesion depth.Therefore,the clinical applicationm of 1-minite topical fluoride application which appears to have a similar anticariogenic efficacy to 4-minite fluoride application may be encouraged.

신경회로망 제어기를 이용한 PID 파라미터 추정에 관한 연구

權重東,裵銀敬,金恩基,全基英,李承桓,吳鳳煥,李勳九,金容珠,韓慶熙 明知大學校 産業技術硏究所 2006 産業技術硏究所論文集 Vol.25 No.-

In this paper, supposed to solve these problem to PID parameters controller algorithm using ANN. In the proposed algorithm, the parameters of the controller were adjusted to reduce by on-line system the error of the speed of IM. In this process, EBPA NN was constituted to an output error value of an IM and conspired an input and output. The performance of the self-tuning controller is compared with that of the PH) controller tuned by conventional method (Ziehler-Nichols). The effectiveness of the proposed control method is verified thought the Matlab Simulink and experimental results.

DS-FSK 통신 시스템에 대한 연구

權起弘,金龍顯 대구산업정보대학 1998 논문집 Vol.12 No.2

Recentlly, several experiments have been reported on utilization of commerical power distribution line for data transmission purpose in realizing local FA/HA system. The power line, originally having not been in stalled for the communication purpose, exhibits very poor transmission characteristics; high attenuation rate with severe selective fading, extremely low line impedance and persistent line noises ect.,usually deny the signal transmission unless cumbersome measures are taken, which cannot normally be allowed to local FA/HA system. This paper first studies general characteristics of local power distribution line and selects frequency band relatively recommendable for signal transmission. Also, described are the neccessity of applying spread spectrum technique in order to compete severe selective fading phenomenon existing in the line. The auther then introduces a highly reliable, verstile and yet simple data transmission system designed to meet above requirements. The system operates on the principle of meet DSSS technique but transmits two different carrier frequencies, instead of one depends on the polarity of the SS output. By applying the two carrier meth od, not only the problems related with the carrier synchronization may be eleiminated, but also the process gain of SS block in the system can be multiplied, by the effect of frequency hopping process of the carriers. Acording to the analysis, the simply constructed MODEN can transmits ASCⅡ data of upto 2400 bps through local power distribution line of -7 dB SNR with the error rate of lower than 10^(-5) when the 36 kHz PN frequency is used. The auther also studies the maxmum allowable numbers of the MODEN unit s multiplexed on a power line under given error rates. The analisis shows, with the proposed units, upto 8 subscribers may be cdmmunicate with the error rate of less than 10^(-4) In order to verify the analisis, 10 test sets have been built; each composed of a spreader/corelator, carrier modulator and a PN generator triggered from fixed phase of power line voltage. A carefully designed mathing transformer has been used in order to assure perfect matching to power line impedance which drops sometimes down to less than 10 ohms. Pairs of carrier frequeneies for each unit have been selected from 100-150 kHz band. For the standard pairs built for the unit system measur ements, 113 kHz and 137 KHz have been used. A series of measurements have been conducted on dummy line as well as on actual commercial lines with the results fairely matched to the analytical values.

2004년 7월 봇돌바다의 영양염과 Chlorophyll-a의 단기 변동

최용규,조은섭,권기영,이용화,이영식 한국환경과학회 2005 한국환경과학회지 Vol.14 No.4

In order to study the temporal variations of nutrients and chlorophyll-a in the Bottol Bada, three field observations were carried out on 20, 23 and 26 July, 2004. The low N:P values exhibit nitrogen deficiency during the periods of observation. This result is not representative of typical summer environment in the southern coast of Korea. The possible mechanisms are as follows: 1) The freshwater inflow was not sufficient for the supply of nitrogen because the total precipitation was 11.9 mm in July, 2004. This amount is no more than 5% in normal precipitation in July. 2) There was an inflow of oceanic water under the subsurface into the Bottol Bada. Even though the oceanic water comprises more nutrients, it produces the stratification between the surface and the subsurface water and seems to prevent the supply of nutrinets to the surface layer. 3) The high chlorophyll-a concentration of 1.2 ㎍/L was shown near the narrow channel between Gae-do and Geumo-do. This seems to be resulted from the inflow of water from Gamak Bay.

외배엽 이형성증 환자의 임상적 치험례

오소희,권순원,김종수,김용기,임헌송 대한소아치과학회 2000 大韓小兒齒科學會誌 Vol.27 No.2

Ectodermal dysplasia(외배엽 이형성증)은 외배엽성 기관에 한가지 이상의 선천적 이상소견을 특징으로 하는 질환이다. Ectodermal dysplasia는 약 120종류 이상이 보고되고 있고, 이 중 Hypohidrotic ectodermal dysplasia가 가장 잘 알려져 있으며 이는 성염색체 열성인자에 의해 유전되며 남성에서 호발한다고 한다. 임상증상으로는 무한증, 감모증, 무치증 혹은 핍지증이 가장 특징적이다. 이외에도 무피지증, 손톱이형성증, 가늘고 성긴 머리카락, 두드러진 이마, 안장코, 돌출된 안와상부, 입술의 돌출과 함께 피부가 건조하고 땀샘이 결핍되어 있어서 더위를 참지 못하고 발열이 일어나기 쉽다. 본 증례의 환자는 단국대학교 치과병원 소아치과에 내원한 6세 6개월된 남아로써 무치증을 보이는 Hypohidrotic ectodermal dysplasia로 진단되었고 환자의 심미적, 기능적 결함을 해소하기 위해 총의치로 치료를 시행하는 동안 다소의 지견을 얻어 이를 보고하는 바이다. 주요어 : 외배엽 이형성증, 무치증, 총의치

전기적 노이즈에 의한 누전차단기의 오동작에 관한 실험적 연구

김태만,권용준,기도형 한국산업안전학회 2002 한국안전학회지 Vol.17 No.1

The purpose of this study was to investigate effect of electrical noise on malfunction of the earth leakage circuit breaker. A three-way experiment for studying its malfunction was conducted, in which electrical products such as radio, alternating current arc welder and cellular phone, distance from the earth leakage breaker to electrical products, and whether or not the earth leakage breaker is contained in the steel box were employed as experimental variables. Eleven earth leakage breakers frequently used in real situations were tested in each experimental treatment. The electrical products were used for generating electrical noise that is known to be able to cause malfunction of the earth leakage breaker. The results showed that except a case for one of the 11 earth leakage breakers when the radio made by M company was located 30 cm ahead of the breaker, malfunction did not occur in any other experimental treatment. Consequently, it is suggested that the breaker should be normally used for preventing electricity-related accidents without fear of its malfunction in industrial sites.

상아질 결합제가 컴포머의 불소유리에 미치는 영향에 관한 연구

윤여상,김종수,권순원,김용기 대한소아치과학회 2001 大韓小兒齒科學會誌 Vol.28 No.2

본 연구의 목적은 와동 충전시 충전재와 지질 사이에 개재되는 상아질 결합제가, 수복물에서 유리되는 불소가 와동 벽으로 침투하는 과정에 어떠한 영향을 주는지를 조사함이었고, 부가적으로 레진 강화형-글라스 아이오노머 시멘트의 접착에도 상아질 결합제를 도포하는 것이 체질과의 결합력을 강화시킬 수 있는지에 대해 평가하고자 하였다. Fuji II LCR와 Dyract APR를 선정하여 상아질 결합제의 도포 여부에 따른 불소 유리량 측정과 전단 결합 강도도를 비교분석하였으며, 치질 내로의 불소 침투 양상은 교환 시기에 있는 재2유구지에 Fuji II LCR와 Dyract APR를 충전하고 3주내에 발거하여 EPMA필 분석하였다. 상아질 결합제는 불소 유리량을 현저하게 감소시키는 것으로 나타났으며(p<0.05) Fuji II LCR의 경우 상아질 결합제의 도포가 결합강도를 증가시키지 못하였다. EPMA분석결과 상아질 결합제는 충전재로부터 유리되어 나오는 불소가 치질 내로 확산되는 것을 방해하는 것으로 확인되었다. It is well known that glass-ionomer cement and compomer can release fluoride which can inhibit the progresion of dental caries. The purposes of thins study were to evaluate whether the fluoride from fluoride-containing ailing materials can penetrate the dentin bonding adhesive and the dentin bonding adhesive can increase the bond strength of resin-modified glass lonomer. The amount of fluoride release from resin-modified glass lonomer and compomer was measured during 28 days of period find statistically analyzed by t-test. The bond strength of each material with/without dentin bonding adhesive was measured and also statistically analyzed by t-test. The distribution of fluoride from each material into the tooth was explored by electron probe microanalysis system (EPMA). The expenmental teeth used were second primary molars about to exfoliate. The amount of fluoride from each material was diminished by dentin bonding adhesive during 28 days(p<0.05) and the bond strength was not increased by dentin adhesive in resin-modified glass ionomer. The bond strength of group VI was not detectable. The distribution of fluoride from earth material into teeth was according to dentino-enamel junction and dispersed into pulp from pulpal floor. The widest distribution was shown in resin-modified glass ionomer cement filled without the application of dentin bonding adhesive.

지난 4년간 학회지 "신경정신의학" 심사 평가보고

오병훈,권준수,남궁기,김승현,지익성,김창윤,하규섭,박원명,김성곤,오강섭,김정범,이수정,정한용,이창욱,박용천,이영문,김세주,이병욱 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.5

Four Years Reports of "Journal of Korean Neuropsychiatric Association" during 2001 to 2005 were evaluated by 18 Editorial Board of Korean Neuropsychiatric Association. We investigated the articles to specific fields and rejection rate etc. by different section chiefs. Although several problems concerning review time duration and rejection guideline issues indicated but generally all reviewer processes proved relatively clear and concise criteria. Through these objective and systematic evaluation Processes, "Journal of Korean Neuropsychiatric Association" will develop a good journal.

스트레인 게이지법을 이용한 복합레진과 컴포머의 중합수축 평가에 관한 연구

김윤철,김종수,권순원,김용기 大韓小兒齒科學會 2002 大韓小兒齒科學會誌 Vol.29 No.1

본 연구의 목적은 다양한 중합과정에 따른 복합레진과 컴포머의 수축 양상을 스트레인 게이지법(strain gauge method)을 이용하여 평가해보고자 하는 것이었다. 광중합기는 기존의 할로겐 시스템인 XL 3000(3M, USA)과 최근 소개된 plasma arc curing 시스템인 Flipo(LOKKI, France)를 사용하였고, 충전 재료는 복합레진인 Z-100(3M, USA)과 컴포머인 Dyract AP(Dentsply, Germany)를 사용하였다. 주형과 치아 와동 내에 충전된 실험재료의 중합수축을 각각 측정하였으며, 만능 시험기를 이용하여 압축강도를 측정하였다. 중합수축 측정 결과 모두 중합 초기에는 일시적인 재료의 팽창을 나타냈고, 그 후 약 1분간은 수축량이 급격히 증가하다가 증가의 폭이 점차 감소하는 양상을 보였다. 전반적으로 컴포머를 사용한 군에 비해 복합레진을 사용한 군에서 중합수축이 크게 나타났으며, plasma arc curing 시스템을 사용한 군에 비해 기존의 광조사 시스템 군에서 더 큰 중합수축을 보였다. 압축강도의 측정결과는 컴포머 군에 비해 복합레진 군에서 크게 나타났다. 이상의 결과를 종합해 볼 때, plasma arc curing unit와 컴포머의 사용은 시술시간의 단축과 항우식 효과를 감안한다면 소아치과 영역에서의 사용이 긍정적으로 고려될 수 있다고 생각된다. The purpose of this study was to compare the polymerization shrinkage and the compressive strength of composite and compomer cured with two different light sources; conventional halogen-light curing unit and recently developed plasma arc curing unit. The 'strain gauge method' was used for determination of polymerization shrinkage and the compressive strength was measured by universal testing machine. The results of the present study can be summarized as follows: 1. Filling materials in polyethylene molds showed the initial expansion in the early phase of polymerization. This was followed by the rapid contraction in volume during the first 60 seconds and gradually diminished as curing process continued. 2. The polymerization shrinkage in tooth samples was generally lower than in the mold samples. 3. The generally lower amount of linear polymerization shrinkage was observed in compomer and plasma arc curing unit group when compared to composite and conventional curing unit. 4. The higher compressive strength values was found in composite groups reagrdless curing methods. The results of this study strongly support the application of plasma are system and fluoride-containing compomer in the field of clinical pediatric dentistry claiming its effectiveness in curing the esthetic dental materials and the anticariogenic capacity.

제약적 최소자승추정을 이용한 미분기반 다중계층 광류 추정

김영춘,신용달,권기구 永同大學校 2001 硏究論叢 Vol.7 No.1

본 논문에서는 광류 제약 방정식(optical flow constraint equation) 및 영상의 공간적인 상관성을 고려하여 제약적 최소자승추정(constrained least square estimation)을 이용한 미분기반 다중계층(multiscale) 광류 추정 방법을 제안하였다. 제안한 방법은 인접한 화소간의 움직임 속도가 유사하다는 가정 하에 다중계층으로 광류를 추정하였다. 또한 본 논문에서는 광류 제약 방정식 및 인접한 화소간의 움직임 속도가 유사하다는 가정에 의하여 발생하는 오차를 줄이기 위한 정제(refinement) 방법도 제안하였다. 제안한 방법이 기존의 방법에 비하여 더욱 정확하게 광류를 추정할 수 있음을 실험을 통하여 확인하였다. In this paper, we propose a gradient-based multiscale optical flow estimation method using the constrained least-square estimation, considering the spatial correlation of the image. The basic assumption of the proposed method is that the neighboring pixels are having a similar velocity. Also we propose a refinement method to decrease the error, reviving optical flow constraint equation and neighboring pixels are having a similar velocity. Experimental results show that the proposed method can more accurately estimate the optical flow than the conventional methods.