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      • DSP를 이용한 정밀속도제어 SRM의 고효율 구동

        김창섭,최기영,안진우,표성영 경성대학교 공학기술연구소 1999 공학기술연구지 Vol.6 No.-

        본 논문에서는 맥동토오크와 부하토오크의 변화로 인한 속도변동을 줄이기 위해 동적 도통각 제어 원리를 이용한 PLL(Phase Locked Loop) 속도제어 방식을 채택하였다. SRM 구동 시스템에 적용한 결과 전동기는 강인한 정속도 운전을 할 수 있으며, 또한 선행각을 조정함으로서 고효율 구동을 할수 있었다. 구성된 시스템은 운전속도와 부하의 변화에 따라 선행각이 증감함으로써 뛰어난 동적 속도제어 특성을 갖고 있으며, 인버터 인가전압을 제어하여 선행각을 조정함으로서 전부하 영역에서 높은 효율특성을 가진다. SRM 구동 시스템의 PLL 속도제어와 고효율 제어를 위한 도통각제어를 위해 TMS320F240 DSP를 사용해 구현함으로서 디지털 제어기를 유연성과 소형화를 꾀하였다. Switched Reluctance Motor(SRM) drive system is known to provide good torque characteristics and high efficiency drive. However, speed variation caused by higher torque ripple is one of main drawback. The Phase-Locked Loop(PLL) technique in conjunction with dynamic dwell angle control has good speed regulation characteristics. In this paper, appropriate advance angle control for high efficiency drive and PLL technique for accurate speed control is proposed. A TMS320F240DSP is used to realize this drive system. Test results show that the system has good dynamic and precise speed control ability as well as high efficiency.

      • KCI등재

        Tamoxifen사용과 동반된 자궁내막암 2예

        정재혁,안기헌,신병섭,김기형,윤만수 대한산부인과학회 2003 Obstetrics & Gynecology Science Vol.46 No.5

        Tamoxifen citrate는 원발성 유방암에서 보존적 요법으로 사용되어온 에스트로젠 길항제, 효현제의 양 성격을 가진 비 스테로이드성 제제이다. tamoxifen의 장기 사용시 자궁내막조직에 에스트로젠 양상의 영향을 미치며 자궁내막증식증, 자궁내막암, 자궁내막 폴립 등을 야기시키는 것으로 보고되고 있다. 최근 저자들은 본원 산부인과에서 유방암으로 광범위 유방절제술을 시행받고 수술 후 보조적 요법으로 각각 26개월, 29개월간 tamoxifen 치료를 시행해 온 환자에서 자궁내막암 2예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다. Tamoxifen citrate is a non-steroidal agent that has demonstrated estrogen agonist and antagonist properties and has found successful application for all stages, as adjuvant therapy, in the treatment of primary breast cancer. The drug was originally introduced for the treatment of high risk postmenopausal women or for postmenopausal patients with advanced disease. Since then, it was reported that long term treatment schedules could provide maximal benefit in preventing recurrences. Recent analyses of clinical trials have demonstrated an increase of disease-free survival in breast cancer among patients with positive estrogen receptor tumor. Tamoxifen is now recommended for chemoprevention of breast cancer in healthy high risk women. An agonist estrogenic effect upon the endometrium, the so called "paradoxical" effect, is suggested when proliferative changes, such as endometrial hypeplasia, adenocarcinoma, polyps. We report a case of endometrial cancer which developed in premenopausal patients with breast cancer under tamoxifen therapy.

      • KCI등재

        혐기성 소화에 대한 식종원 및 암모니아 농도의 영향

        김양지,김성일,신범식,안기섭,김종수 한국환경농학회 2004 한국환경농학회지 Vol.23 No.1

        혐기성 소화에서 미생물에 저해/독성 물질로 알려진 암모니아의 농도와 식종원에 따른 영향 을 회분식 반응기를 이용하여 분석하였다. 식종원은 고농도의 암모니아에 장기간 적응된 축 산농가 축산폐수 집수조의 슬러지 그리고 저농도의 암모니아에 노출된 하수종말처리장 혐기 성 소화조 슬러지를 사용해서 COD 제거율과 biogas 발생량으로 측정된 혐기성 미생물의 활성에 저해영향을 주기 시작하여 3,500 ㎎-N/L에서는 더욱 심하였다. 암모니아 저해 농도 범위에서 휘발성 유기산의 농도는 50㎎/L 범위로 유지되므로 메탄생성균 뿐만 아니라 산생 겅균도 저해영향을 받는 것으로 나타났다. 축산폐수 집수조 슬러지로 식종된 경우 암모니아 농도가 TAN으로 2,500∼3,500 ㎎-N/L 범위에서도 COD 제거율과 biogas 발생량의 감소폭 은 미미하였으나, 하수종말처리장 혐기성 소화조 슬러지로 식종된 경우 암모니아 농도가 증 가할수록 COD 제거율과 biogas 발생량은 큰 폭으로 감소하였다. 결과적으로 암모니아에 장 기간 순응된 슬러지로 식종한 경우 암모니아의 저해 농도에 대하여 적응도 빨랐으며 저해영 양도 적었다. The seeding sources and concentration of ammonia on anaerobic digestion were investigated by batch culture bioreactors. The sourcces of seeding on anaerobic digestion were from swine wastewater collection pit of a hog raising farm and from anaerobic digestion sludge of a municipal sewage treatment plant. The inhibition of ammonia on anaerobic microoganisms was initiated at ammonia concentration of 1,500 ㎎NH₄-N/L and it s effect was increased by increasing ammonia concentration up to 3,500 ㎎NH₄-N/L, regardless the sources of seeding as evidenced by decreases in COD removal efficiencies and biogas yields. The inhibition occurred to not only methanogens but also acidogens since the concentration of volatile fatty acids was maintained at 50 ㎎/L. The COD removal efficiency and biogas yield were maintained constantly while increasing ammonia concentration up to 3,500 ㎎NH₄-N/L when swine wastewater collection pit was used as a seeding; however, those were decreased while increase ammonia concentration when anaerobic digestion sludge was used as a seeding. The results indicate that the seeding acclimated to high concentrations of ammonia for long time was easy in adaptation to high ammonia concentration and less subjective to ammonia inhibitory effects.

      • KCI등재

        신조된 고속 캐비테이션 터널에서 환기 초공동 실험 수행을 위한 기초 연구

        백부근(Bu-Geun Paik),김민재(Min-Jae Kim),정영래(Young-Rae Jung),김경열(Kyoung-Youl Kim),안종우(Jong-Woo Ahn),설한신(Han-Shin Seol),김기섭(Ki-Sup Kim),이승재(Seung-Jae Lee) 대한조선학회 2018 大韓造船學會 論文集 Vol.55 No.4

        In the present works, the High-speed Cavitation Tunnel (HCT) has been designed and manufactured to have the large test section to conduct various supercavitation experiments. The large amount of air ventilated behind a cavitator produces lots of tiny bubbles, which prevent clear observation of supercavitation at the test section. To collect small bubbles effectively, a bubble collecting section of large volume is equipped upstream of the test section. HCT has the test section dimension of 0.3<SUP>H</SUP> × 0.3<SUP>W</SUP> × 3.0<SUP>L</SUP> ㎥ and provides maximum flow speed of 20.4 m/s at the test section. The blockage and Froude effects on the ventilated supercavitation are investigated successfully at the test section. The basic studies such as the supercavitation evolution, drag measurements and cavity shape extraction with air flow rate are also carried out in HCT.

      • KCI등재

        유조선 종통보강재와 횡늑골 연결부의 피로강도 평가용 자동화 시스템 개발

        홍기섭(Ki-Sup Hong),김성찬(Sung-Chan Kim),안재욱(Jae-Wook Ahn),김성기(Seong-Ki Kim) 대한조선학회 2009 大韓造船學會 論文集 Vol.46 No.5

        Ship structure is composed of the welded mixture members which are plate and stiffeners. Ship structure is also influenced by variable loadings such as wave and inertia load. There have been several fatigue damage problems on the connection between longitudinal and transverse web due to wide usage of high tensile steel and adoption of wide web space to improve shipbuilding productivity. It is impossible to estimate the fatigue lives for all connection details through refined fatigue analysis. It is necessary to use the simplified approach for the fatigue life estimation of the connection details. PLUS analysis, which is suggested by the classification society, is one of the simplified approaches and is widely adopted to get fatigue lives for the connection details along whole cargo hold area. However, ship building yards still have difficulties to get fatigue lives due to large amount of calculation and time even if this approach reduce the time and amount of calculation. This paper treats the computing system developed to reduce efforts of estimating the fatigue lives. The influence factors of mean shear stress and local dynamic pressure are easily calculated and fatigue lives for all hot spots can be estimated automatically by the developed computing system. It is possible to reduce computing time and efforts to get the fatigue lives for the connection details between longitudinals and transverse webs along the ship. This system was applied to get fatigue lives on the connection details of a VLCC and verified the availability.

      • KCI등재

        축대칭 몰수체의 유효반류 추정

        김기섭(Ki-Sup Kim),문일성(Il-Sung Moon),안종우(Jong-Woo Ahn),김건도(Gun-Do Kim),박영하(Young-Ha Park),이창섭(Chang-Sup Lee) 대한조선학회 2019 大韓造船學會 論文集 Vol.56 No.5

        An axisymmetric submerged body(L=5.6m, Diam=0.53m) is installed in Large Cavitation Tunnel (LCT) of KRISO and the nominal and total velocities without and with the propeller in operation, respectively, are measured using Laser Doppler Velocimeter (LDV). The flow field is nearly axisymmetric except the wake of the supporting strut, and is considered ideal to study the hydrodynamic interaction between the propeller and the oncoming axisymmetric sheared flow. The measured velocity data are then provided to compute the propeller-induced velocity to get the effective velocity, which is defined by subtracting the propeller-induced velocity from the total velocity. We adopted, in computing the induced velocity, two different methods including the vortex lattice method and the vortex tube actuator model to evaluate the resultant effective velocity distribution. To secure a fundamental base of experimental data necessary for the research on the effective wake, we measured the drag of the submerged body, the nominal and total velocity distributions at various axial locations for three different tunnel water speeds.

      • Korean Dictionaries and Some Model Dictionaries of the World : Critical Essays toward the Plan for a New Korean Dictionary

        Lee, Sang Sup,Nam, Ki Shim,Ahn, Sam Huan,Choi, Young Ai,Hong, Chai Song 연세대학교 언어정보개발원 1988 사전편찬학 연구 Vol.1 No.1

        After briefly reviewing the history of lexcoigraphy in modem Korea, Nam Kishim tackles many problems created by the general deficiency of current Korean monolingual dictionaries in phonological morphological and semantic points. For example, most Korean dictionaries do not treat such phonological changes as the shortening of the stem vowel ㅓ in 더운, the prenominal form of the adjective 덥다, whose stem vowel ㅓ is pronounced long. He also takes issue with the practice of Korean dictionaries of including all kinds of proper names on little reliable principles : a typical dictionary enters a 600m-high hill while excluding better-known mountains higher than that. Hong Chai-song concentrates on the often misguiding information on transitive / intransitive verbs in current dictionaries. For example, a representative dictionary designates the verb 뛰다 simply as intransitive. But it is quite often used as an transitive also. In the sentence, 철수는 운동장을 뛰었다, 운동장 is the object of the transitive verb 뛰다. How could the compilers miss such an obvious fact? Hong suggests that they may have not been interested in being grammatically informative. A historical survey of the Oxford English Dictionary(OED) is given by Lee Sang-sup, with special emphasis on the vast amount of quotations from real sources contributed by thousands of volunteer readers through several decades and on its unwavering historical principle. A comparison between the OED's definition of Kimchi and a Korean dictionary's 김치 is given, showing the difference of principle in treating the same lexical item. Ahn Sam-huan presents a detailed account of Grimm's Deutsches Wo¨rterbuch which took generations of German lexicographers 133 years from its inception to its completion in 1971. On the basis of his study, Ahn suggests that future dictionary makers should cooperate as a group on a long-range comprehensive project. A moltivolume dictionary is an all-important cultural event for the whole nation, not to be influenced by private commercial interests. Choi Young-ai's survey of Chinese lexicography highlights the now on-going publication of 漢語字典 and 漢語詞典, admirable results of the cooperative effort of hundreds of Chinese scholars, a modus operandi for the Yonsei University graze to adopt in planning a new dictionary of the Korean language.

      • KCI등재후보

        하시모토 갑상선염을 동반한 유두상 갑상선암의 임상병리학적 특징

        강상현,하태권,박하경,이홍태,신재호,안민성,김광희,배기범,김태현,최창수,김진수<SUP>1<.SUP>,김기훈<SUP>1<.SUP>,김운원<SUP>1<.SUP>,김상효,Sang Hyun Kang,Tae Kwun Ha,Ha Kyoung Park,Hong Tae Lee,Jae Ho Shin,Min Sung Ahn,Kwang Hee Kim,Ki Beom Bae,Ta 대한갑상선-내분비외과학회 2013 The Koreran journal of Endocrine Surgery Vol.13 No.1

        '스콜라' 이용 시 소속기관이 구독 중이 아닌 경우, 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

        Purpose: Hashimoto's thyroiditis (HT) is an important cause of hypothyroidism caused by autoimmune chronic lymphocytic thyroiditis. In order to attain a better understanding for use in treatment of papillary thyroid carcinoma (PTC) coexisting with HT, we conducted an analysis of the clinicopathologic features, as well as the importance of HT as a prognostic factor. Methods: In this retrospective study, we analyzed 341 patients who were histopathologically diagnosed with PTC following surgery. Results: PTC coexisting with HT was observed in 19.6% (67 patients) of all PTC patients. A statistically significant gender difference was observed in the group with HT (two male vs. 65 female), with a higher positive rate of anti-thyroglobulin antibody and smaller tumor size, compared to the PTC group without HT. When tumor size increased, a lower coexistence rate of HT was observed. No significant differences were observed in multifocality, cervical lymph node (LN) metastasis, coexistence of benign nodule, and extent of LN dissection. However, frequency of extrathyroidal extension was significantly lower and total thyroidectomy rate was higher in the group with HT. TNM stage and AMES stage were similar in both groups; frequency of high MACIS score showed a significant decrease in the group with HT. The recurrence rate and disease-free survival in patients with PTC were not significantly affected by coexistence of HT. Conclusion: We found a significant relationship with gender, extrathyroidal extension, and tumor size in PTC coexisting with HT. However, no significant differences in recurrence rate and disease-free survival were observed between groups. Therefore, coexistence in PTC could not be applicable as a prognostic factor of PTC.

      • KCI등재

        보조생식술후 태아에서 발생한 de novo 염색체 이상

        안기헌,이국원,주종길,신병섭,최욱환 대한산부인과학회 2002 Obstetrics & Gynecology Science Vol.45 No.9

        불임 환자 치료를 위한 보조생식술은 날로 그 시술 기관과 시행수가 증가되고 있을 뿐만 아니라, 치료성적도 괄목한 만큼 개선되는 등 불임증 진단과 치료에 많은 발전이 있어 왔다. 여러 보고에 의하면 체외수정 시술후 출생한 태아에서 전체적인 기행의 발생위험은 자연임신에 비해 증가하지 않는다고 한다. 저자들은 세포질내 정자 주입술후 배아이식술로 임신된 임부와 체외수정후 배아이식으로 임신된 임부에서 양수검사를 통해 각각 상호전좌의 형태인 46,XX,t(6;14) 1예와 터너 증후군의 변형인 46,X,iso(Xq) 1예를 경험하였다. 이에 보조생식술후 발생한 de novo 염색체 이상 2예를 문헌 고찰과 함께 보고하는 바이다. We experienced two cases of de novo fetal chromosomal abnormalities after assisted reproductive technology (ART): One case was reciprocal translocation 46,XX,t(6;14)(p21.3;q12) after intracytoplasmic sperm injection & embryo transfer (ICSI-ET) and the other case was 46,X,iso(Xq) after in vitro fertilization & embryo transfer (IVF-ET), both were diagnosed prenatally by amniocentesis and postnatally cord blood culture. We report these cases with a brief review of literatures.

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