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.

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.

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.

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.

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.

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

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.

랫드에서 단일시험법을 이용한 반하 물추출물의 생식독성시험

이기남,유욱준,백인정,연정민,남상섭,이범준,남상윤,김윤배,강현규,안병우,김대중,황방연,노재섭,홍정섭,성하정,김순선,조대현,윤영원 충북대학교 동물의학연구소 2006 Journal of Biomedical and Translational Research Vol.7 No.1

본문참조

Performance Analysis of a Mixed-Flow Pump for Waterjet Propulsion

Ahn Jong-Woo,Kim Ki-Sup,Park Young-Ha,Kim Kyung-Youl,Oh Hyoung-Woo The Society of Naval Architects of Korea 2005 Journal of ship and ocean technology Vol.9 No.2

A mixed-flow pump is largely applied for waterjet propulsion in high-speed vessels because of excellent cavitation performance. For the present study, we analyze the performance of mixed-flow pump, which is composed of impeller and stator. The test device for a mixed-flow pump was installed in the test section in the KRISO cavitation tunnel. The performance tests of two mixed-flow pumps were carried out with the test device at various flow rates using various nozzles. The test results agree fairly well with the predicted results by commercial CFD code. The test device is available for verification of impeller performance together with CFD analysis

항공기용 Mg-Zn합금의 주조특성및 내식성에 대하여

안인섭,김기원,허보영 국립경상대학교 공과대학 부설 첨단소재연구소 1995 尖端素材 Vol.5 No.-

두만강(도문강)유역 토지자원 종합평가 : 수출자유지역단지개발을 중심으로 For the Development of the Export Processing Zones

이기석,이옥희,최한성,김종범,남영,안재섭 한국 지리·환경 교육학회 1999 한국지리환경교육학회지 Vol.7 No.2

The main purpose of this study is to identify best location for establishing an Export Process Zone (EPZ) based on analysis of population, industries, resources, and land use patterns along lower Tumen River area which is known as the new multi-nation cooperative project under sponsorship of UNDP. Two methods were used in this study; one was an overview survey of the related variables through field work and the general economic evaluation of resource potential; the other one is the development of land resource evaluation system and land use map construction using satellite TM image, and mapping analysis of locational index based on GIS method. The study area selected includes Tumen city, Hunchun city, and Jing Xin area, which are geographically suitable for the development. In both the winter of 1997 and the summer of 1998 extensive field work was conducted with the Chinese partners. Among the major variables of population, industries, resources, and land use for EPZ, population in the urban area has rapidly increased as a whole, but decreased in the rural sector. Additionally, the number of Chinese-Koreans has gradually out-migrated, and the labor market in this given region is becoming unstable even though over 60% of population included non-agricultural occupation. Water resource, energy source, forests are indicating high potentiality for future development, but other industrial structures are not enough to support the operation of EPZ in general. Except for the heavy forest area, the result of land resource evaluation in most areas was classified as "First Class" with high quality. Traditional land use maps provides very limited information of the spatial organization, but TM land use image gives practical information because of precision and spatial linkage. Using GIS techniques, three types of locational patterns for potential development area were produced. Among them, the analysis based on the "natural break point" is identified as the appropriate result. In order to discover the locational advantage for EPZ, two methods out of the three (TM land use image and integrated map by GIS) were mutually complementary in terms of practical usefulness and functional linkage. Actually, TM land use image provided an infra-base for understanding dynamic land use patterns. Furthermore, it reveals the spatial relationship between arable land and grass, which is difficult to find in ordinal land use maps. On the other hand, even though GIS potential map uses a relatively large scale cell(1km x 1km) as analysis unit of area, its final map provides a practical base for the priority over the judgement of the best EPZ location. In conclusion, among three areas surveyed along the Tumen River area, Hunchun city and its surrounding area was identified as the best site for the EPZ establishment, Tumen and Jing Xin area were considered equally second best sites. The evaluation methods used and developed in this research were feasible but need further modification through other area case studies.