에어컨 냉각 팬용 브러쉬레스 DC 전동기의 역기전력 분석에 대한 연구

조정현,김지현,정정원,황흥식,이치우 경성대학교 공학기술연구소 2012 공학기술연구지 Vol.18 No.-

Compared to conventional dc motors having the combination of commutators and brushes, a brushless DC (BLDC) motor is one of the highly efficient motors due to its electrical commutation without a brush, and this feature allows the BLDC otor to be more suitable for an application requiring no maintenance due to mechanical wear between a commutator and a brush. Also, the BLDC motor has a few benefits over both a dc motor and an induction motor such as high dynamic response, high efficiency, logn life span, and low noise in wide speed-torque region. This paper investigates the variation of voltage induced in phase windings in a BLDC motor in several cases with respect to stack length, steel grade, and coil material. This study is numerically conducted and it is verified from the theoritical point of view by comparing the result of simulation with that of experimental measurement.

Thermocouple을 이용한 Buchanan Plugger 표면의 온도상승 분석

조진숙,황윤찬,김선호,황인남,최보영,정영진,정우남,오원만 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.4

This study was performed to confirm the actual temperature rise on the surface of Buchanan plugger by evaluating the temperature rise on the surface of it, the peak temperature of pluggers of various size using thermocouple. The heat carrier system 'System B Heatsource' (Model 1005, Analytic Technologies, USA) and the Buchanan pluggers of F, FM, M and ML sizes are used for this study. The temperature was set to 200 which Dr. Buchanan's "Continuous wave of condensation" technique recommended on digital display and the power level on it was set to 10. The touch mode was used. Five thermocouples were placed in direct contact with the surface of each size of Buchanan's pluggers at 1 ㎜ increments from the tip to the 4 ㎜ length of shank. Each thermocouple was secured with cyanoacrylate adhesive and orthodontic resin block. The two wire leads of each thermocouple were connected to the appropriate channels of Data Logger. This was configured to simultaneously record input from the five thermocouples. The heat control spring was touched for 1, 2, 3, 4 and 5 seconds, and the temperature rise on the surface of the pluggers were measured at 1 sec intervals for more than 5 seconds with an accuracy of 0.01. Ten trials was determined for each plugger. The average of temperature rise and standard deviation was calculated for each size of plugger. The data were statistically analyzed by one-way ANOVA to determine their significance. The results as follows. 1. The position at which the temperature peaked was approximately at 1∼2㎜ far from the tip of Buchanan plugger (p<0.01). 2. The peak temperature was 215.25±2.28℃ in F plugger, 185.94±2.19℃ in FM plugger, 169.51±9.12℃ in M plugger, and 160.79±1.27℃ in ML plugger and the peak temperature was highest in F type and followed by, in descending order, FM type, M type. ML type showed the lowest peak temperature (p<0.01). This results suggest that the actual temperature on the surface of the pluggers does not correlate well with the temperature set on digital display. Heat concentrates around the tip. The larger plugger reveals lower temperature rise relatively.

개에서 발생한 이혈종의 임상적 관리

이우철,윤기영,서경원,최호정,정성목,송근호,조종기,박성준 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2012 動物醫科學硏究誌 Vol.19 No.1

A 14-year-old male pomeranian was present with swollen left ear. The swelling occurred from base to apex of pinna. Otitis externa persisted for two years. Hematological and serum biochemistry values were not remarkable. The surgery treatment was the most appropriate method among indwelling drain, surgical, and steroid treatment in the aural hematoma because the dog was very sensitive to touching pinna and the size of aural hematoma. Longitudinal incision was applied after general anesthesia. Cefovecin was injected to prevent secondary infection. The outcome of surgery was good. There was no evidence of recurrence for one year.

Homomorphic Encryptions at a Long Distance Through Quantum Key Distribution Protocols

JEONG*, Kabgyun,KIM, Yong Jin,YOON, Jong Beom,KIM, Geon Woo,CHO, Gueha,KIM, Suntaek Korean Physical Society 2019 새물리 Vol.69 No.2

강직성 슬관절에서의 슬관절 전치환술

조우신,박종희,김정민,오세관 대한슬관절학회 2003 대한슬관절학회지 Vol.15 No.1

목적: 강직이 동반된 슬관절염 환자에서 슬관절 전치활술의 문제점, 결과 및 합병증을 분석하고자 하였다. 대상 및 방법: 1994년 1월부터 2000년 12월까지 슬관절 강직(운동 범위 50도이하)이 있는 환자에게 슬관절 전치환술을 시행하여 2년 이상 추시가 가능하였던 16례를 대상으로 하였다. 수술은 관절 강직이 발생한지 평균 12.2년(1~40년)에 시행하였으며, 추시기간은 평균 3.3년(2~6년)이었다. 16례 중 남자 3례, 여자 13례였고, 평균 나이는 55.8세(34세~75세)였다. 감염에 의한 후유증 6례로 가장 많았고 그 외 퇴행성 관절염 4례, 외상 후 관절염 3례, 류마티스성 관절염 3례의 순이었다. 술 후 평가는 추시기간 중의 운동 범위와 HSS score 및 합병증을 분석하였다. 결과: 관절 운동 범위는 술 전 평균 31.6도(0~50도)에서 추시시 평균 95.4도(80~120도)로 증가하였으며, 1례에서만 5도의 굴곡 구축이 있었다. HSS score는 술 전 평균 59.6점(43~76점)에서 추시시 평균 84.6점(76~92점)으로 향상되었다. 1례에서 수술 중 슬개건 부분파열이 있었으나 보조기 착용과 적극적 재활로 술 후 1년째 90°의 관절 운동이 가능했다. 표재성 감염 1례는 창상의 변연절제술 후 피부이식으로 치유되었고, 심부 감염된 3례는 추후 관절 유합술을 시행하였다. 결론: 슬관절 전지환슬은 강직된 슬관절의 기능을 회복시킬 수 있는 좋은 술기이지만 감염등의 합병증을 고려해서 시행되어야 한다. Purpose: To evlauate the results of TKRA (Total knee replacement arthroplasty) for the treatment of stiff knee. Methods & Materials : TRKA has been performed for 18 cases of stiff knee ( ROM < 50° ) between January 1994 and December 2000. 16 cases which have been followed up for more than 2 years were analysed. Average follow-up was 3.3 years(2~6 years). 3 were male and 13 female. The average age was 55.8 years(34~75 years). Sequales of infection were most with 6 cases and followed by osteoarthritis (4 cases, 2 cases had been performed arthroscopic debridement) and rheumatoid arthritis (3 cases) and traumatic arthritis (3 cases) in order. TKRA was performed on average 12.2 years (1~40 years) after knee stiffness has been developed. We evaluate the results with ROM, HSS score and complications. Results : Average ROM was increased from 31.6°(0°~50°) preoperatively to 95.4°(80°~120°) postoperatively. 5° of flexion contracture was present in only 1 cases. Average HSS score was improved from 59.6 points preoperatively to 84.6 points postoperatively. The patella tendon was partially ruptured in 1 case surgery, but by brace application and rehabilitative exercise, ROM was improved to 90°, 1 year post operatively. There were 1 superficial skin infection which was resolved by revision of wound and skin graft, and deep infection in 3 cases, which needed knee fusion finally. Conclusion : TKRA is a good method for improving function in knee stiffness although infection risk is high.

PWC170의 算出方法 評價에 關한 硏究

趙庚旭,金泰完,張鳳愚,張鍾仁 忠北大學校 平生體育硏究所 1985 平生體育硏究所 論文集 Vol.1 No.-

The purpose of this study is to estimate the maximal oxygen up-take and the physical work capacity by four experimental methods in PWC170. The subjects of this study start to pedal the bicycle ergometer at the three work loads; the first work rate with 450∼600kpm/min, the second work rate with 600∼750kpm/min, and the third work rate with 750∼900kpm/min. Each exercise bout is 6 minutes long. We used a pedal frequency of 50 revolutions per minute. The first method is the first and second work rates the second method the second and the third work rates the third method the first second and hird work rates and the fourth method an integration by the third work rate. We measured and recorded the heart rate during the last 30 seconds of every minute of exercise. Since the subjects worked in a steady state, it is not necessary that they should exercise exactly 6 minutes each time. If problems happened during the taking of heart rate or other data, we continued to exercise another 30 to 60 second. The estimation of maximal oxygen uptake and physical work capacity was conducted by work loads and heart rates during exercise. The results are as follows: 1. The estimation by four different, methods showed 2∼3 persentile difference in maximal oxygen uptake(1min, ml/kg/min) and PWC170(kpm/min, kpm/kg/min). 2. The estimation by four different methods did not show significant differene, therefore for the estimation we had better use simplified method for the first work rate and the second work rate.

중질유 탈황공정 폐촉매로부터 유가금속의 회수에 관한 연구

조정우,이정희,구덕모,김기석 嶺南大學校 工業技術硏究所 1995 工業技術硏究所論文集 Vol.23 No.1

In order to selectively recover by the extractive separation the value metals including V, Mo, Ni, Co, and Al from the spent catalysts removed from the resid desulfurization processes, we investigated the following: how to efficiently remove the nonmetallic impurities from the spent catalyst by roasting how to optimize the pore structure of roasted spent catalyst, how to select the suitable leachants and extractants, how to optimize the conditions of leaching/extraction, and how to determine the effective sequence of selectively recovering the value metals. With regard to roasting of spent catalyst, 550℃ was found to be the optimal roasting temperature in terms of sulfur removal and solubility of roasted catalyst in the sulfuric acid leaching solution as the specific surface area, porosity, and residual sulfur content were measured for the spent catalysts roasted at various temperatures in the tubular furnace. For the spent catalysts roasted at temperatures above 650℃, the efficiency of selectively recovering the value metals was diminished due to the decreased surface area and porosity, thereby the lowered solubility of roasted catalyst in the sulfuric acid leaching solution. In the case of roasting at 550℃, the ratio of (oxygen flow rate)/(volume of spent catalyst sample) equal to 30min?? was optimal for the efficient removal of sulfur from the spent catalyst. With regard to the selective recovery of value metals by leaching/extraction operations, two spent catalysts of different metal compositions as well as two model oxide mixtures simulating the metal compositions of those catalysts were experimented to determine the suited leachants/extractants and search for the effective sequences of selective recovery. The sequential recovery operation consisting of the solid-liquid separation via leaching and the liquid-liquid separation via extraction made it possible to selectively recover the value metals from both the model oxide mixtures and the spent catalysts. The differences in particle structure and component distribution between the model oxide mixture and the spent catalyst accounted for the differences in leaching, leaching conditions, and recovery sequences between the two. The sequences of selectively recovering the value metals which are relatively simple and of good potential to be applied in commercial scale were developed for the spent catalyst of two different metal compositions

자색고구마가 사염화탄소 투여에 의한 흰쥐의 간손상 보호에 미치는 영향

조영자,김현아,방미애,오용비,정병춘,문윤호,정우진 한국식생활문화학회 2003 韓國食生活文化學會誌 Vol.18 No.3

The purpose of this study was to investigate the effects of dietary purple sweet potato(lpomoea batatas) powder on serum lipid levels and antioxidative enzymes in normal and pretective effect on hepatotoxicity rats induced by carbon tetrachlolide. Four groups of rats (3-week-old inbred Sprague-Dawley male rats) were normal rats fed control diet(C)_(1) induced hepatotoxicity rats fed control diet(EC)_(1) normal rats fed purple sweet potato diet(P), and induced hepatotoxicity rats fed purple potato sweet diet(EP). Rats were induced by single injection of 50% carbon tetrachloide(0.1 mL/100 g B.W., i.p.). The rats were fed ad libitum each of the experimental diet for 5 weeks. After 5 weeks the rats were sacrificed and activities of antioxidant enzymes and lipid peroxidation products were determined in their liver homogenates. But serum concentrations of lipid was not significant in all groups. Serum alanine aminotransferase(ALT/GPT) and aspartate aminotransferase(ALT/GPT)of the EC and EP groups were heigher than the C and P groups. The hepatic glucose 6-phosphatase(G9Pase) activity of the group fed purple potato diet(P) was lower than the other groups(p<0.05). However, The glutathione peroxidase(GPx) activities was not statistically different between the groups. Renal glutathione S-transferase(GST) activity of the EC and EP groups were lower than the C and P groups(p<0.05). In conclusion, these results suggest that purple sweet potato is believed to be possible protective effect on hepatotoxicity rats induced by carbon tetrachlolide.

Helicobacter pylori와 대장균의 Shuttle Vector 개발

조명제,이우곤,이상룡,김경희,안영숙,김성희,김현주,류복덕,최여정,윤영혜,백승철,전영석,이광호 경상대학교 유전공학연구소 1997 遺傳工學硏究所報 Vol.16 No.-

In this study, a vehicle vector using cryptic plasmids was constructed for gene transfer in Helicobacter pylori. pHP51(3.9 kb) and pHP489(1.2 kb) were selected for constructing vectors from cryptic plasmid of H. pylori isolates in Korea. The HindⅢ-digestedDNA fragment(1.2kb) of pHP489 and 1.6kb DNA fragment of pHP51 were ligated with a kanamycin resistance gene(aph3'-Ⅲ) from C. jejuni to produce the recombinant plasmids pHP489K and pHP51K, respectively. Transformation frequency of pHP51K by electroporation was low. But pHP489K could be effectively transformed into various H. pylori strains. In order to design an intermdiate vehicle vector for gene transfer into H. pylori, pBlueHP489K was prepared by recloning pHP489K DNA into pBluescript and pTZ19R vector. This vector permitted the DNA fragment containing pHP489 sequence, aph3'-Ⅲ, and cloned DNA to be cut and self-ligated in the SacⅠ site after cloning. ureA and ureB gene were inserted into pBlueHP489K, resulting in pBlueHP489K/AB. The DNA fragment containing pHP489, kanamycin resistance gene(aph3'-Ⅲ), and urease structural gene was cut away from pBlueHP489K/AB and self-ligated to generate pBlueHP489K/AB. pBlueHP489K/AB made urease-negative H. pylori strains restore their urease activity. By this experiment, pBlueHP489K was confirmed to be the vehicle system for transferring H. pylori genes.

고등어 및 정어리 선어의 휘발성성분

조우진,김훈,정연정,이영미,정은정,차용준 창원대학교 생활과학연구소 2002 생활과학연구 Vol.- No.6

This study was conducted to identify volatile compounds, associating with quality deterioration, which may play roles as indicators for quality assessment in fresh mackerel and sardine. Volatile compounds were analyzed by liquid liquid continuous extraction(LLCE)/GC/MSD methods. A total of 83 and 81 volatile compounds were detected in fresh mackerel and sardine, respectively, and these compounds were mainly composed of aldehydes(12 in raw mackerel, 11 in raw sardine), ketones(7, 4), alcohols(15, 14), esters(1, 3), aromatic compounds(13, 15), terpenes(5, 7), S-containing compounds(2, 2), hydrocarbons(13, 11) and miscellaneous compounds(2, 1). Most of compounds including carbonyls, alcohols, aromatic compounds and hydrocarbons were derived from lipid oxidation, and some compounds were detected from microbial degradation. It was supposed that LLCE method was proper to seek indicators for quality assessment in fresh mackerel and sardine, because of various volatile compounds derived from nonthermal lipid oxidation.