수종 치주큐렛의 작업측 마모도의 비교연구

신동환,임성빈,정진형,Shin, Dong-Whan,Lim, Sung-Bin,Chung, Chin-Hyung 대한치주과학회 1999 Journal of Periodontal & Implant Science Vol.29 No.3

The purpose of this study was to evaluate the degree of wear of periodontal curet's cutting edges made by three different manufacturers. In the first case of the experiment, this study was done with each new curett in the following three experiment. Twelve new double-ended No. 11/12 Gracy curettes from three different manufacturers (A, B and C) was randomly selected from our stock at first test. They were weared by wear tester with fixed pressure and limited distance. This study measured the width of worn curettes'cutting edge. The results were as follows ; 1)In 50 times experiment, this study discoverd that each manufacturer's curette was appeared with different degree of wear (p<0.01) 2)In 100 times experiment, this study result similarly to the 50 times experiment(p<0.01). 3)In 150 times experiment, the result of this study were alike as the X50 experiment and X100 experiment. In the second case of the experiment, the study was done with a curett of a manufacturer in the following three experiment. Two double-ended No. 11/12 Gracy curette from three different manufactures (A, B and C) was randomly selected from our stock at second test. 1)In 50 times experiment, this study discovered that each manufacturer's curette was appeared with different degree of wear (p<0.05). 2)In 100 times experiment, the result was same, compared with the 50 times experiment. 3)In 150 times experiment, this study also discovered that the result was same with the result of the upper two cases. In conclusion, this study discovered that the two cases of experimental were shown with a same result.

치은박리소파술시 metronidazole gel 병용이 유년성치주염 치료에 미치는 영향

신동환,이동원,문익상,Shin, Dong-Hwan,Lee, Dong-Won,Moon, Ik-Sang 대한치주과학회 2001 Journal of Periodontal & Implant Science Vol.31 No.4

The aim of the study was to investigate the effect of surgical therapy combined with the usage of metronidazole gel in the treatment of juvenile periodontitis by comparing clinical indices of flap operation along with application of metronidazole gel and flap operation only. Comparing clinical indices of the baseline, 3 months after surgery, 6 months after surgery statistically, the results are as follows; 1. Bleeding on probing (BOP) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p<0.05). BOP increased 0.9% in the control group 6 months after surgery, while in the experimental group, decreased 4.7% (p>0.05). However, there was no statistically significant difference in these groups (p>0.05). 2. Pocket probing depth (PPD) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p<0.05). PPD increased 0.lmm in the control group 6 months after surgery, while in the experimental group, no increase of the depth could be observed (p>0.05). However, there was no statistically significant and difference in these groups (p>0.05). 3. Loss of attachment level(LOA) was decreased significantly both in the experimental group and the control group at 3 months after surgery (p<0.05). LOA increased 0.2mm in the control group 6 months after surgery, while in the experimental group, increased 0.3mm However, there was no statistically significant difference in these groups (p>0.05). In conclusion, flap operation was effective on the treatment of juvenile periodontitis. However, combined therapy of metronidazole gel could not give rise to any significant adjunctive effect on the treatment outcome.

임프란트 미세나사선이 주위골 수준변화에 미치는 영향에 대한 1년간의 전향적 비교 연구

신동환,조규성,박광호,문익상,Shin, Dong-Hwan,Cho, Kyoo-Sung,Park, Kwang-Ho,Moon, Ik-Sang 대한치주과학회 2003 Journal of Periodontal & Implant Science Vol.33 No.3

The success of dental implant therapy relies mainly upon the presence and maintenance of bone adjacent to implant. An 1-year prospective study was performed, upon the patients who were diagnosed as having chronic adult periodontitis, and had been treated with dental implant. The purpose of this study was to measure the radiographic bone level changes proximal to Astra Tech Single Tooth Implants (ATST, Astra Tech AB, $M{\"{o}}lndal$, Sweden) with microthread and Astra Tech TiOblast Implant (ATTB) without microthread supporting fixed partial prosthesis. Measurements were used to determine mean marginal bone loss during the first year of loading, 17 subjects with its partial prosthesis supported by 37 implants were followed up for an 1-year period. The marginal bone loss of implants was positively correlated with the retention factor, microthread($Microthread^{TM}$) in crestal area of ATST. The results were as follows. 1. The mean marginal bone loss of ATST was 0.226${\pm}$0.395mm, while ATTB was 0.440${\pm}$0.360mm. There was a statistically significant difference between ATST and ATTB (p<0.05). 2. The mean bone loss of the upper jaw fixtures was 0.269${\pm}$0.265mm for ATST and 0.529${\pm}$0.417mm for ATTB . There was a statistically significant difference between ATST and ATTB (p<0.05). In the lower jaw the corresponding figures were 0.167${\pm}$0.231mm and 0.313${\pm}$0.214mm, respectively. There was no significant difference between ATST and ATTB (p>0.05). 3. The mean bone loss of ATST was lower than that of ATTB at all sites according to bone quality. There was a statistically significant difference between ATST and ATTB at bone quality type III(p <0.05). In conclusion, the mean bone loss of ATST was smaller than that of ATTB . Therefore, the retention factor of crestal area, microthread ($Microthread^{TM}$) was effective to maintenance of marginal bone level around fixture.

랫트뇨중의 Alanine Aminopeptidase와 $\beta$-Glucuronidase 측정에 의한 신장독성 평가에 관하여

신동환,이창우,Shin Dong-Hwan,Lee Chang Wo 한국임상수의학회 1991 한국임상수의학회지 Vol.8 No.1

Present experiment was performed in order to establish the optimal reaction conditions for determination of urinary AAP and GRS activities and to investigate the applicability of urinary AAP and GRS in nephrotoxicity test in rat. The results were as follows ; 1. The optimal pH of phosphate buffer for determination of urinary AAP activity was 7.8. 2. The Michaelis constant of urinary AAP ranged from 0.8 to 1.0mmol/$\ell$ 3. The optimal wave length for determination of urinary GRS activity was 405nm. 4. The optimal pH of acetate buffer for determination of urinary GRS activity was 5.6. 5. The Michaelis constant of urinary GRS ranged from 0.65~0.79mmo1/$\ell$. 6. The AAP activities in gel-filtered samples were significantly higher than those in crude samples. Mean values of AAP activities in gel-filtered samples and crude samples were 29$\pm$20 and 20$\pm$13U/$\ell$, respectively. 7. There was not significant difference between gel-filtered samples and crude samples in urinary GRS activities. Mean values of GRS activities in gel-filtered samples and crude samples were 57$\pm$40 and 56$\pm$39U/$\ell$, respectively. 8. Limits of linearity of urinary AAP and GRS activities were 2.0 and 3.6U/$\ell$, respectively. 9. Within-run imprecisions of the assays, were acceptable, as the coefficients of the AAP activities ranged from 5.5 to 6.3% and those of GRS activities ranged from 1.4 to 6.2%, respectively. 10. Urinary AAP excretion was 675$\pm$227mu/24hrs.kg before administration of potassium dichromate, and increased significantly to 4246$\pm$2567mU/24hrs.kg within 24 hours after administration of potassium dichromate. 11. Urinary GRS excretion did not increase significantly after administration of potassim dichromate. 12. From these findings it is concluded that urinary AAP excretion is early and sensitive Indicator to detect kidney damage in nephrotoxicity experiment.

소방관 보조로봇 플랫폼의 내충격성능 향상을 위한 구조 보강 설계

신동환,김윤구,안진웅,Shin, Dong-Hwan,Kim, Yoon-Gu,An, Jinung 대한임베디드공학회 2011 대한임베디드공학회논문지 Vol.6 No.5

In this paper, we describe the structural reinforcement approach of the throwing-type firefighter assistance robot which can be thrown into a fire site to monitor inside the place and search trapped people while ensuring a firefighter's safety. The reinforcement design is focused on high strength with low weight for the robot. The in-depth structural analysis of the platform is carried out to track down the weakest part, especially with the 1.8m height of drop test. The analysis is verified by comparing with the 1.8m height of the drop test of the throwing-type firefighter assistance robot. The optimal approach for improving the strength of the weakest part aims at topological equivalent and equivalently stress distributed shape.

Design and Fabrication of 26.4 GHz Local Oscillator for Satellite Payload

신동환,류근관,장동필,이문규,염인복,오승엽,Shin Dong-Hwan,Ryu Keun-Kwan,Chang Dong-Pil,Lee Moon-Que,Yom In-Bok,Oh Seung-Hyeub The Korean Institute of Communications and Informa 2006 韓國通信學會論文誌 Vol.31 No.2A

본 논문에서는 위성 탑재체용 26.4 GHz 국부 발진기를 설계 제작하였다. 제작된 발진기는 고안정도와 고신뢰도를 갖는 기본 주파수 발생부와 기본 주파수 발생부로부터 생성된 8.8 GHz의 신호를 3체배하여 26.4 GHz의 최종 발진 주파수를 만들어내는 주파수 체배부로 구성되어 있다. 기본 주파수 발생부는 샘플링 위상비교기(Sampling Phase Detector)를 이용한 위상 고정 방식의 발진기로 구성하였으며 고안정도를 갖는 OCXO를 기준 주파수원으로 사용하였다. 주파수 체배부는 자체 설계한 MMIC 3체배기와 증폭기를 이용하여 크기와 무게를 줄일 수 있었다. 개발된 국부 발진기는 +11 dBm 이상의 출력 전력과 10 kHz와 100 kHz의 오프셋 주파수에서 각각 -96 dBc/Hz와 -105 dBc/Hz의 위상 잡음 특성을 나타내며, 설계 요구규격을 모두 만족한다. A 26.4 GHz phase locked oscillator(PLO) for communication satellite transponder is developed. The PLO consists of fundamental frequency generation module(FFGM) and frequency multiplication part(FMP). The signal of 26.4 GHz is generated through frequency tripling process of 8.8 GHz fundamental frequency. Phase locking technique using sampling phase detector(SPD) is adopted to design the FFGM. The MMIC tripler and amplifier are also designed for the reduction of the size and mass of FMP. The phase noise characteristics are exhibited as -96 dBc/Hz at 10 tHz offset frequency and -105 dBc/Hz at 100 kHz offset frequency, respectively, with the output power over 11 dBm. All performance parameters are complied with the design requirements.

비정상 시변신호의 AR모델 파라메터 인식을 위한 최적의 웨이브렛 선택

신동환,김성환,Shin, D.H.,Kim, S.H. 한국음향학회 1996 韓國音響學會誌 Vol.15 No.4

본 논문에서는 최적의 웨이브렛 선택방법과 이 선택된 웨이브렛으로 F-검정을 이용하여 AR파라메터를 전개시키는 방법을 제안하였으며 웨이브렛 선택 방법으로서 평가함수를 도입하였다. 이 평가함수를 이용하여 웨이브렛들(D4-D20)을 합성신호에 대해서 시험하였다. 이때 선택된 웨이브렛을 이용하여 합성신호와 실제 음성신호에 대해서 AR파라메터들을 웨이브렛 전개 했을때의 웨이브렛 계수를 구하였다. 제안된 방법을 평가하기 위해서 칼만필터 알고리즘과 비교하였다. 그 결과 제안된 알고리즘이 칼만필터보다 약5-10dB정도 더 우수한 성능을 나타내었다. In this paper, we proposed the method of optimal wavelet selection and wavelet expansion of AR(autoregressive) parameters by selected wavelet using F-test. A cost function is introduced as a wavelet selection method. Using this cost function, wavelets (D4 to D20) are tested to the synthesized signal. With this selected wavelet, we get the wavelet coefficients of AR parameters to both synthesized signal and real speech signal. To evaluate the proposed method, this wavelet based algorithm is compared with the Kalman filering algorithm. As a results, the proposed method shows a better performance by about 5-10dB than the Kalman filter.

Ka 대역 위성 출력 전력 제어 기술 연구

신동환(Dong Hwan Shin),문성모(Sung Mo Moon),염인복(In Bok Yom) 한국통신학회 2012 한국통신학회 학술대회논문집 Vol.2012 No.6

Series Resonant Reflector 를 이용한 MMIC 주파수 2 체배기 설계 및 제작

신동환(D. H. Shin),류근관(K. K. Ryu),염인복(I. B. Yom) 한국통신학회 2005 한국통신학회 학술대회논문집 Vol.2005 No.6

임금근로 장애인의 사회적 배제에 미치는 영향요인 연구

신동환(Shin, Dong-hwan) 경기연구원 2014 GRI 연구논총 Vol.16 No.3