國産스테인레스鋼線系 矯正用線材의 開發과 物理的 性質에 關한 硏究

권오원,성재현,이기대,경희문 대한치과교정학회 1989 대한치과교정학회지 Vol.19 No.2

The physical properties of seven sizes of control groups and experimental group in stainless steel orthodontic wires were studied in tension, hardness, bending, torsion and observation of microstructure. The wires (0.40 - 0.90mm dia.) of round type were tested in the as-received condition. The wires of control groups were TRU-CHROME and REMANIUM, and experimental group was SK wire which was developed by ourselves and made in Korea. The results were as follows: 1. The chemical compositions of control groups and experimental group were austentie stainless steel wires of SOS 304. 2. Higher values of tensile and yield strength in tension were control group I, experimental group, control group II. Maximum tensile and yield strength of experimental group were 203.63 ±1.41kg/mm²in 0.70mm diameter and 148.96 ± 4.88kg/mm² in 0.60mm diameter, and maximum elongation was 5.20 ± 0.57% in 0.45mm diameter. 3. Hardness values of experimental group were similar to control groups. Maximum hardness values were 596.2 ± 13.66 Hv in 0.45mm diameter wire of control group I, 590.5 ± 20.08Hv in 0.50 mm diameter wire of control group II, and 563.6 ± 5.35 Hv in 0.70mm diameter wire of experimental group. 4. Torsion properties of experimental group were similar to control group I and more than control group II. Maximum torsion cycles were 31.8 ± 2.48 in 0.45mm diameter of control group I,17.4 ± 4.84 in 0.60mm diameter of control group II, and 24.6 ± 3.04 in 0.45mm diameter of experimental group. 5. Maximum bending cycles of experimental group were smaller than control groups. Maximum bending cycles were 9.00 ± 0.00 in 0.50mm diameter wire of control group I, 10.0 ± 0.82 in 0.40mm diameter wire of control group II, and 8.0 ± 1.26 in 0.50 mm diameter wire of experimental group. 6. Microstructures of experimental and control groups co-existed with martensited austenite structure and elongated austenite structure. 7. The direction of wire fracture was propagated parallel to torsion direction typically and there was no probability showing wire fracture at inclusions and surface scratches. 8. The type of wire fracture was brittle fracture at initiation site and ductile fracture at core.

정상교합자의 치열궁 형태

권용철,성정옥,권오원,성재현 대한치과교정학회 1989 대한치과교정학회지 Vol.19 No.1

This study was designed to investigate dental arch shapes buccally and lingually at Bracket Level of Koreans. This involved studying 63 inviduals (37 males, 26 females) with normal occlusion ranging in age from 17 to 24 yesrs old. The landmarks were digitized and measurements and statistical analysis were performed by NEC 9801 V-M computer. The Results were as Follows: Bicanine width, Bipremolar width and Bimolar width were larger in males than in females. Buccal and lingual arch form and coordination form were obtained by NEC 9801 V-M computer. The parabolic equations which represents buccal and lingual arch form were obtained.

국내 혈액질환 환자에서 침습성 아스페르길루스증의 구제치료로서 Voriconazole의 효과와 안전성

권재철,김시현,최수미,최재기,이동건,박선희,최정현,유진홍,신완식 대한감염학회 2010 감염과 화학요법 Vol.42 No.1

Background: Invasive aspergillosis (IA) is associated with significant morbidity and mortality in patients with hematologic malignancies. We investigated the efficacy and safety of voriconazole (VCZ) when used as salvage therapy for IA in Korean adults with hematologic malignancies who had not responded to prior antifungal therapy. Materials and Methods: We retrospectively reviewed data, collected from January 2007 to October 2008, from patients with proven or probable cases of IA. All were probable IA cases, except for one proven case. All cases were refractory or intolerant to antifungal therapy prior to administration of VCZ. Efficacy and safety were assessed in patients treated with VCZ for more than 3 days and for more than one dose, respectively. A favorable response [complete (CR) or partial (PR)] was defined by significant improvement of all clinical symptoms, signs, and radiologic abnormalities. Results: Fifty patients who met the inclusion criteria were enrolled. There were 27 male and 23 female patients with mean age of 44.4 years (range, 15-65 years). Underlying diseases were acute leukemia (35 cases), chronic myelogenous leukemia (4 cases), myelodysplastic syndrome (3 cases), lymphoma (3 cases) and other hematologic diseases (5 cases). Twenty-two patients had received chemotherapy and 13 patients had undergone hematopoietic stem cell transplantation. The lung was the main infection site (94%) followed by the sinus (6%). Amphotericin B deoxycholate alone was the most frequent previous antifungal therapy. The mean duration of antifungal therapy prior to VCZ therapy was 13.9±8.8 days (2-44 days). The median duration of VCZ therapy was 19 days (interquartile range, 49 days). Sixteen patients (32.0%) showed favorable responses (CR:PR=8:8) at the end of VCZ therapy. The numbers of patients with stable disease, progression and death were, 6 (12%), 6 (12%) and 22 (44%) respectively. Most of those with unfavorable responses had relapsed underlying malignancies or refractory graft versus host diseases. Twelve patients developed drug-related adverse events but only one patient stopped VCZ treatment prematurely. Conclusions: VCZ demonstrated an acceptable level of toxicity in patients with hematologic malignancies but further studies are required to prove its efficacy as salvage therapy.

부정교합 아동의 성장에 따른 연조직 측모의 변화

권오원,경희문,장병천,성재현,김정민 대한치과교정학회 1989 대한치과교정학회지 Vol.19 No.3

This investigation was undertaken to know how soft tissue facial profile could changed with age. The 3 serial lateral cephalometric roentgenograms of the twenty nine boys and twenty six girls between 9 and 13 years of age were studied and the findings seemed to warrant the following conclusions. 1. The author made the tables of means, standard deviations in each item, sex, age. 2. Soft tissue facial angle, soft tissue facial convexity including the nose tended to increase, but others tended to remain relatively stable. 3. Facial soft tissue thickness increased with age and the growth of facial soft tissue in the middle rgion (point A, LS, LI)was greater than others in the facial region. 4. In the soft tissue vertical proportions, GI'-Sn/Sn-Me' was 1.1, Sn-St/St-Me' was 0.51:1, Sn-LI/LI-Me' was 0.82.1 and those were stable with age.

이동 단말기용 내장형 slot 안테나 구현

권원현,허재헌 안양대학교 산업기술연구소 2002 自然科學硏究 Vol.9 No.-

본 논문에서는 이동통신 단말기용 내장형 안테나를 연구 개발하였다. 개발된 안테나는 동축형 구조를 갖고 있으며, 스트립 선로를 이용하여 급전 구조를 구현하였다. 안테나의 공진부는 슬롯 구조를 갖는 동축 슬롯 공진형으로 설계하여 IMT-2000 대역인 2.0 GHz 대역에서 공진이 가능하도록 하였다. 구현된 안테나는 26 x 13 x 1.2 ㎣의 크기를 지녀 이동통신 단말기에 쉽게 내장할 수 있음을 알 수 있었다. In this paper, embedded antenna for wireless mobile phone is developed. Developed antenna uses the coaxial type slot structure and its feeding line is implemented by using microstrip line. Resonator part of slot antenna is designed utilizing coaxial type slot resonator structure, and its design parameters are optimized to have 2.0 GHz resonance frequency for IMT-2000 handset. Implemented antenna has 26 x 13 x 1.2 ㎣ physical dimensions, which can be easily applicable to an embedded antenna of mobile phone.

개인휴대 단말용 무선부 회로 설계 개발

권원현,허지헌,홍진표 안양대학교 자연과학연구소 1996 自然科學硏究 Vol.3 No.-

본 논문에서는 미래의 개인휴대통신 서비스용 단말인 1세대 PDA (Personal Digital Assistant)의 설계, 개발 및 시험에 관하여 서술하였다. 135 x 76 x 18 ㎜ 크기의 개발된 제품은 기존의 전자수첩에 pager의 기능을 부가시킨 Pager PDA로서 320 MHz 대역의 1200bps/2400bps 정보를 모두 수신 가능하며, 전국적인 서비스가 가능한 광역 페이져의 형태로 설계하였다. 이를 위해 사용지역에 따라 주파수가 자동으로 변환되는 PLL 형태의 국부 발진기를 설계 개발하였다. 시험결과 개발된 제품은 일반 페이져가 만족하여야 할 IEC 표준 규정을 모두 만족하였으며, 수신감도 또한 우수함을 알 수 있었다. In this paper, first generation of PDA(personal digital assistant) in which the function of pager is merged into electronic notebook has been developed and commercialized to fulfill the requirement of PCS equipment. Developed product of 135 x 76 x 18 ㎣ size operates in 320 MHz paging frequency bands and receives 1200bps or 2400bps paging data. And also, it adopts PLL type local oscillator whose operating frequency changes with the user locations to ensure the nationwide paging services. Experimental results show that the developed product meets well all of the IEC specifications and has high receiving sensitivity.

산청군 산림지가 형성요인에 관한 연구

권철현,이상태,신현철,최재채,정영관 경상대학교 농업생명과학연구원 2003 농업생명과학연구 Vol.37 No.1

본 연구는 산청군 남부와 북부지역 361개소의 공시지가와 일반시가에 대하여 분석하였다. 지가 형성요인에 대하여 단계별 회귀분석을 실시하였으며, 그 결과는 다음과 같다. 남부지역에 대한 공시지가와 관련된 5변수 모형에 의한 추정식은 Y = 332.1973 +0.0099X_26 - 0.3577 X_8+ 0.0291X_24 - 2.6768X_2 - 26.1452X_3 이며, 회귀식에 대한 설명력은 90%로 높게 나타났으며, 일반시가에 대한 추정식은 Y = 1035.7976 -185.8280X_21 -3.3937X_1 + 405.6658X_19 -0.4703X_8 이며, 추정식에 대한 설명력은 92%롤 비교적 높게 나타났다. 북부지역에 대한 지가 형성요인에 의한 공시지가 추정모형은 Y = 176.7875 + 0.0205X_25 -0.1168X_8 + 0.0015X_26 -46.3447X_21 로 추정되었으며, 회귀식에 대한 설명력은 96%, 일반시가의 추정 모형은 Y = 203.0697 + 0.0430X_25 + 0.0027X_26 -28.8276X_4 -46.7856X_21 -0.0007X_23 으로 추정되었으며, 회귀식에 대한 설명력은 90%로 나타났다. 이상과 같이 접근요인은 부의 영향을, 그 외 다른 요인들은 지가에 양의 영향을 미치는 것으로 나타났다. This study was carried out to analyze the publicly announced land price and actual land price compared to the northern and southern region of 361 forest land place in Sanchung county. To decipher factors for making forest land price it used the stepwise regression analysis. And the result of analysis are followings; Y = 332.1973 +0.0099X_26 - 0.3577 X_8+ 0.0291X_24 - 2.6768X_2 - 26.1452X_3 (R^2=90%) and the estimation equation of actual price analyze the publicly announced and actual price compared to the northern and southern regions of Sanchung county of price was obtained as Y = 1035.7976 -185.8280X_21 -3.3937X_1 + 405.6658X_19 -0.4703X_8(R^2=92%). In the northern region, the estimation equation of publicly announced land price by the factors for making forest land price was obtained Y = 176.7875 + 0.0205X_25 -0.1168X_8 + 0.0015X_26 -46.3447X_21(R^2=96%) and the estimation equation of actual price was obtained as Y = 203.0697 + 0.0430X_25 + 0.0027X_26 -28.8276X_4 -46.7856X_21 -0.0007X_23(R^2=90%). In the result of the stepwise regression analysis, it was a showed negative effect of the proximity factor and the positive effect between others factor and land price.

矯正用 接着劑의 引張强度

權五源,成在鉉 慶北大學校 齒科大學 1984 慶北齒大論文集 Vol.1 No.1

The requirement of ideal orthodontic direct-bonding adhesive should include longevity of bond, ability to withstand a variety of forces, resistance to the degrading effects of the oral environment, and ability to be easily removed without affecting the integrity of the enamel. The purpose of this study was to evaluate the adhesive properties of recently developed 3 orthodontic direct bonding adhesives by testing the tensile strength. 75 premolars extracted for orthodontic treatment were used. The tensile strength was tested by Tensilon/UTM-1-10000C after 24 hours from bonding. Following results were obtained; The mean tensile strength of each product was higher than the maximum force(29㎏/㎝) exerted on a bracket during orthodontic treatment. The tensile strength of Mono­Lok was statistically higher than Concise and Dyna­Bond, although there was no difference the tensile strength of Concise and Dyna­Bond statistically. Of the failure, the combination type of failure(68%), where part of the adhesive remained on the tooth and part of the bracket was the most common type. The second type of failure (22.7%) occurred at the tooth­adhesive interface and the last type of failure (9.3%) occurred at the adhesive­bracket interface.

탈수 케이크의 내부 특성 I-수분 및 비저항 분포

권재현 인제대학교 1999 仁濟論叢 Vol.14 No.3

정수장 슬러지와 침출수 처리장에서 발생하는 활성슬러지의 탈수성을 비교 평가하고 케이크의 내부특성을 규명하였다. 본 연구에서는 부크너 판넬 실험에 의해 여과구성식을 결정하였는데, 압축계수 n가 모두 1 이상으로 고압축성임을 알 수 있었고 활성슬러지의 압축성이 상대적으로 더 높았다. 압축성은 압축계수 n 뿐만 아니라 경험상수 pa에 의해서도 큰 영향을 받았는데 작은 압력 차에도 압축성이 높고 폐색되기 쉬운 케이크 내부 특성을 갖고 있는 활성슬러지(침출수)의 경우 여재 부근 약 10% 구간에 부분공극율이 급속히 감소하는 밀막이 존재하여 케이크내 공극율 변화율이 가장 큰 값을 나타내었고 이로 인해 평균비저항이 크게 상승함으로서 고압축성 슬러지의 밀막 형성과 케이크 폐색성이 슬러지 탈수의 중요한 저해 요인임이 밝혀졌다. Dewatering is an essential process in accomplishing volume reduction or moisture reduction of water and wastewater treatment plant sludges. This moisture removal results in decreased transportation costs, improved sludge handleability and provides a more readily combustible material for incineration. Because the cost of sludge dewatering is often the greatest expense of sludge management, there is much interest in improving the design, energy efficiency and performance of sludge dewatering facilities. Compressible sludges used in this study formed a thin skin next to the media during filtration. This implied that porosity(moisture content) and specific resistance changed rapidly at low pressures.

3차원 디지털 모형을 이용한 양악 치조골 전돌자의 치열궁 특성 연구

권오원,이수경,성재현 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.1

최근 안모의 심미성이 중요시되면서 구순 돌출로 인한 비심미성을 해소하고자 내원하는 양악 치조골 전돌자의 수가 증가하는 추세이다. 그러나 이러한 환자에 대한 연구는 많지 않으며 특히 모형을 이용한 연구는 극히 적다. 모형을 이용하는 연구는 주로 손으로 직접 계측하거나 2차원 평면에서 컴퓨터를 이용하여 측정하였으나 근래에 3차원 레이저 스캐너가 도입되면서 모형을 이용한 연구를 좀 더 빠르고 간편하면서도 정확하게 할 수 있게 되었다. 이 연구는 3차원 디지털 모형을 이용하여 양악 치조골 전돌자의 치열궁 특성을 알아보기 위한 것이다. 양악 치조골 전돌자 20명과 정상교합자 20명을 대상으로 치아 크기, 치열궁 폭경 및 치열궁 길이, 치열궁과 구개의 형태를 비교하여 본 결과 양악 치조골 전돌자는 정상교합자보다 치아 크기가 크고, 하악 견치간 폭경 및 제1소구치간 폭경이 크며 치열궁 길이가 길었다. 그리고 치열궁 형태와 구개 형태에서 정상교합자와 차이를 보였다. Recent beauty trends have caused an increase in the number of bialveolar protrusion patients seeking treatment of lip protrusion. But studies of these patients are not common. Studies using their dental models are especially rare. Dental models have been measured manually or through a computer by digitizing two dimensional images of models. Nowadays, we are able to study dental models more easily and accurately by utilizing the three-dimensional (3-D) laser scanner in dentistry. An investigation was carried out to evaluate the characteristics of the dental arch in a bialveolar protrusion group in comparison with a normal group using 3-D digital models. The normal group was composed of 20 subjects who were selected from students of the School of Dentistry, Kyungpook National University. The bialveolar protrusion group was composed of 20 subjects who visited for treatment at the Department of Orthodontics, Kyungpook National University Hospital. Tooth size, arch width and arch length were measured digitally, and arch shape and the shape of the palate were drawn. Based on the results of this study, the differences of the arch characteristics in the bialveolar protrusion group were that the size of the teeth was larger, mandibular canine width and 1st premolar width were wider, and arch length was longer than in the normal group. And there were differences in the arch shape and the shape of palate between the bialveolar protrusion and normal groups.