비대칭형 보강재 간격에 따른 주기구조물의 SPL모드 해석

김택현,김종태 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.1

The purpose of this research is to study the vibration and acoustic pressure radiation from a thin isotropic flat plate stiffened by a rectangular array of beams, and excited by a time harmonic point force. These constructions on aircraft and ship structures are often subjected to frequency dependent pressure fluctuations and forces. Forces from the these excitations induce structural vibrations in a wide range of frequencies, which may cause such things as acoustic fatigue and internal cabin noise in the aircraft. It is thus important that the response characteristics and vibration modes of such periodic structures be known. From this theoretical model, the sound pressure levels (SPL) in a semi-infinite fluid(water) bounded by the plate with the variation in the locations of an external time harmonic point force on the plate can be calculated efficiently using three numerical tools such as the Gauss-Jordan method, the LU decomposition method and the IMSL numerical package.

스프레이 菊花의 왕겨경 循環式 養液栽培에서 養液의 濃度 및 供給回數의 영향

黃仁澤,金光秀,金月洙,金道翊,金正根 全南大學校 農業科學技術硏究所 1998 農業科學技術硏究 Vol.33 No.-

본 실험은 스프레이 국화 왕겨 배지를 이용한 순환식 양액재배에 있어서 양액의 적정농도와 공급횟수를 구명하고자 실시한 결과 양액 농도 처리에서는 원시표준액의 1.6배 처리구가 초장, 화경장, 경경, 화경수, 엽장, 엽폭, 절화중에서 가장 양호하였고, 1일 공급횟수는 표준농도(1.0배)는 12회가 좋았고 1.3배와1.6배 처리구에서는 6회공급구에서 절화품질이 좋았다. 양액농도별 개화기는 표준농도에 비해 1.3배는 2일, 1.6배 처리구는 3일정도 지연되었다. 양액 농도별 T-N함량은 1.3배 농도에서 많았고 양이온치환용량은 농도가 높은 1.6배 농도에서 높았으며 양액 농도별 엽록소 함량은 1.0배 농도에서 가장 높았다. This experiment was conducted to determine the optimal ionic strength of nutrient solution and fertigation frequency affecting growth and development of spray chrysanthemum (Dendranthema grandiflorum) in recycling system using rice hull. Growth parameters in terms of plant height, flowers diameter, stem diameter, number of flowers, leaf length and width and flower weight were shown better in thd 1.6 ionic strength of nutrient solution than those of 1.0 ionic strength of nutrient solution. Fertigation frequency was good at 12 times during day and night in the standard solution (1.0 ionic strength) while 6 times per day and night were good in both 1.3 and 1.6 strength of nutrient solution. Flowering time was postponed up to 2 day in the treatment of 1.3 ionic strength of nutrient solution, and 3 day in 1.6 ionic strength of nutrient solution. The content of total nitrogen was higher in the 1.3 ionic strength of nutrient solution. Cation exchange capacity was high in the 1.6 ionic strength of nutrient solution and chlorophyll content by the concentrations of nutrient solution was highest in the standard nutrient solution.

독일의 개정 임대차법에 관한 연구 : 주택임대차에 관한 규정을 중심으로 Zum Wohnraummietrecht

윤기택,김종현 청주대학교 학술연구소 2004 淸大學術論集 Vol.4 No.-

Die deutsche Mietrechtsreform fu¨hrt durch die Zusammenfassung des bisher in verschiedenen Gesetzen geregelten mietrechtlichen Vorschriften im Bu¨rgerlichen Gesetzbuch (BGB) und ihre jetzt u¨bersichtliche Gliederung insbesondere im Bereich der Wohnraummiete zu einer erheblichen Vereinfachung fu¨r die Betroffenen. Daneben entha¨lt das im BGB zusammengefaβte Wohnraummietrecht aber auch wichtige inhaltliche A¨nderungen. Wa¨hrend der Mieterschutz an einigen Stellen ausgebaut wird, wird die Vertragsfreiheit gesta¨rkt. Das im deutschen BGB zusammengefaβte private Mietrecht finden sich jetzt in den §§ 535 ff. BGB. Eingeleitet werden sie durch allgemeine Vorschriften fu¨r Mietverha¨ltnisse, also Vorschriften, die unabha¨ngig von der Art der gemieteten Sache fu¨r alle Arten von Mietverha¨ltnissen gelten. Daran anschliβend gliedern sich die Vorschriften u¨ber Wohnraummiete, und schlieβlich u¨ber andere Sache (z.B. Gescha¨ftsraummiete). Das deutsche Wohnraummietrecht ist die Vorschriften u¨ber die Miete und Betriebskosten ausfu¨hrlich geregelt. Fu¨r frei finanzierte Wohnungen werden die Mieten bei Abschluβ des Mietvertrages und bei spa¨teren Mieterho¨hungen grundsa¨tzlich frei vereinbart. Falls Vermieter und Mieter Wohnungen sich aber nicht auf eine frei vereinbarte Mieterho¨hung einigen, kann der Vermieter eine gerechtfertigte Mieterho¨hung nach dem Vergleichsmietensystem durchsetzen. Betriebskosten bleiben insoweit auβer Betracht. Bei der Mieterho¨hung wegen gestiegener Vergleichsmiete darf er die Miete aber innerhalb von 3 Jahren nur maximal 20% erho¨hen. Hat der Mieter das Mieterho¨hungsverlangen erhalten, kann er das Mietverha¨ltnis schriftlich ku¨ndigen. Nach einer vorgesehenen Modernizierung dart der Vermieter die Miete auch erho¨hen. Der Mieter hat dabei ebenfalls ein spezielles Ku¨ndigungsrecht. Bei der Abrechnung der Betriebskosten bringt die Mietrechtsreform durch die neue Regelung mehr Klarheit. Nach dem deutschen Wohnraummietrecht endet ein Mietverha¨ltnis auf bestimmte Zeit mit Ablauf der vertraglich vereinbarten Mietzeit, und ein Mietverha¨ltnis auf unbestimmte Zeit durch eine wirksame Ku¨ndigung nach Abaluf der Ku¨ndigungsfrist. Hier gibt es verschiedene Ku¨nigungsarten. Das Gesetz unterscheidet zwischen ordentlicher und auβerordentlicher Ku¨ndigung (also die fristlose Ku¨ndigung). Bei der ordentlichen Ku¨ndigung kann der Vermieter nur dann ku¨ndigen, wenn er ein berechtigtes Interesse an der Beendigung des Mietverha¨ltnisses hat. Diese Ku¨ndigung des Vermieter muβ der Mieter nicht in jedem Fall hinnehmen. Vielmehr kann er unter bestimmten Umsta¨nde widersprechen und die Fortsetzung des Mietverha¨ltnisse verlangen. Auβerdem kann der Vermieter oder der Mieter das Mietverha¨ltnis fristlos ku¨ndigen, wenn sich ein Vertragspartner so schwerwiegende Vertragsverletzungen zuschulden kommen la¨sst, daβ dem underen Teil die Fortsetzung des Mietverha¨ltnisses nicht zugemutet werden kann. Zwischen deutschem und koreanischem Wohnraummietrecht bestehen die rechtsvergleichend bemerkenswerten Unterschiede im Hinblick auf das Mieterho¨hungsverlangen und das Eintrittsrechtbei Tod des Mieters. Wa¨hrend nach deutschem Wohnraummietrecht fu¨r die Mieterho¨hung sog. die ortsu¨bliche Vergleichsmiete (und auch sog. die Kappungsgrenze) in Betracht kommt, wird im koreanischen Wohnraummietrecht nur prozentuale Obergrenze beru¨cksichigt. Zudem hat im deutschen Mietrecht der Vermieter einen Anspruch auf Zustimmung zur Mieterho¨hung bis zur ortsu¨blichen Vergleichsmiete. Dagegen wird in Korea dieser einfach als Gestaltungsrecht angesehen. Fu¨hrt in Deutschlund der Mieter mit seinem Lebenspartner einen gemeinsamen Haushalt, so tritt mit dem Tod des Mieters der Lebenspartner in das Mietverha¨ltnis ein. Wenn er nicht eintreten will, so wird es mit den Erben des Mieters fortgefu¨hrt. Aber nach dem koreanischen Wohnraummietrecht treten in diesem Fall der Lebenspartner und den Erben des Mieters gemeinsam ein.

Vibration-based Health Index Extraction of Power Transformers

Joung Taek Yoon(윤정택),Kyung Min Park(박경민),Byeng Dong Youn(윤병동),Wook-Ryun Lee(이욱륜) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11

Power transformer is the one of key components of power plants as well as the most frequently failed components. As the failure of power transformers can cause whole plant shut-down and substantial capital loss, failure prediction techniques, i.e., health diagnostics and prognostics, are vital. This study aims at developing a health diagnostics method for oil-filled power transformers using mechanical vibration signal against two mechanical failure modes. The vibration signals are acquired from on-site 36 transformers and two health metrics-mean and standard deviation of spectral responses-are proposed based upon a sensitivity analysis. From the fact that transformers with greater health metrics have long operation years than those with smaller it can be concluded that the proposed health metrics are suitable for health diagnostics and fault identification of power transformers.

Giant Epidermal Cyst on Posterior Scalp

Joung-Taek Im,박보영 대한성형외과학회 2013 Archives of Plastic Surgery Vol.40 No.3

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개선된 복원도 기반 설계 방법론과 풍력발전기 블레이드 설계로의 적용

윤정택(Joung Taek Yoon),윤병동(Byeng D. Youn),왕핑펭(Pingfeng Wang),후차오(Chao Hu) 한국소음진동공학회 2013 한국소음진동공학회 학술대회논문집 Vol.2013 No.10

수주기반 중소 제조기업의 신속 대응형 생산정보시스템 개발에 관한 연구

심정택 ( Joung-taek Shim ),안효정 ( Hyo-jung Ann ),차병철 ( Byung-chul Cha ) 대한설비관리학회 2016 대한설비관리학회지 Vol.21 No.3

This study deals with a quick response production information system(QR-PIS) which applied to rapid growing small and medium-sized manufacturing companies. Although many kinds of production information system are available, the small and medium-sized companies want the system to operate with minimal personnel. So, we studied the success factors of information system and developed quick response production information system based on these success factors. We also showed that our proposed system made it possible to dramatically improve managerial efficiency including reducing information lead-time with minimal personnel.

광센싱 기법을 활용한 LNG 배관 누설감지 시스템에 관한 연구

윤정택(Joung Taek Yoon),최승혁(Seung Hyuk Choi),김태진(Tae Jin Kim),윤병동(Byeng dong Youn) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.5-2

전력용 변압기 기계적 고장 진단을 위한 센서 네크워크 최적화 방법론

윤정택(Joung Taek Yoon),윤병동(Byeng D. Youn),박경민(Kyung Min Park),이욱륜(Wook-Ryun Lee) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

Power transformer is one of the key components in power plants as well as the most frequently failed components. As the failure of power transformers can cause plant shut-down and substantial capital loss, failure prediction techniques, i.e., fault diagnostics and prognostics, are vital. To prevent the mechanical failures of power transformers, vibrations sensors are installed on the surface of oil-filled power transformers. Due to high randomness in vibration and large scale of the transformers, an excessively large number of sensors are generally installed. This study aims at developing the framework of sensor network (SN) optimization to maximize the diagnostic and prognostic capability of the transformers’ potential faults. The vibrations of 36 on-site power transformers were measured. The analysis of the vibrations shows transformer tank vibration characteristics and the importance of high vibration signals in fault detection. The proposed SN optimization framework optimizes the number of sensors and their locations to measure the high vibration signals robustly against system uncertainty. Comparing evaluated health status with maintenance history demonstrates that the proposed framework is capable of estimating transformer health status with the significantly

A newly formulated resilience measure that considers false alarms

Yoon, Joung Taek,Youn, Byeng D.,Yoo, Minji,Kim, Yunhan Elsevier 2017 Reliability engineering & system safety Vol.167 No.-

<P><B>Abstract</B></P> <P>Engineering resilience is a measure of a system's ability to maintain its functionality by resisting and recovering from adverse events. Although false alarms often occur in engineering practice, existing quantitative measures of engineering resilience do not consider false alarms. This makes it difficult to estimate the true degree of resilience and impedes efforts to design a resilient engineered system. This paper thus proposes a new resilience measure that considers false alarms. Two types of false alarms, Type I (false fault) and Type II (false health), are considered and quantified based upon conditional probability theory. A new resilience measure, which considers false alarm rates and reliability, is then formulated in a probabilistic manner. Compared to the conventional resilience measure, the newly formulated resilience measure can estimate system resilience more rigorously and accurately. The effectiveness of the proposed resilience measure is demonstrated via numerical and electro‐hydrostatic actuator case studies.</P> <P><B>Highlights</B></P> <P> <UL> <LI> To the best of our knowledge, a resilience measure considering false alarms is proposed for the first time. </LI> <LI> The state-of-the-art resilience measures are reviewed and their limitations are underlined. </LI> <LI> The effect of false alarms on system resilience is explored in a probabilistic way. </LI> <LI> Case studies showed the superiority of the proposed resilience measure to the existing one. </LI> </UL> </P>