• 대한조선학회지
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• 제11권1호
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• pp.9-16
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• 1974

To contribute towards more accurate estimation of the virtual inertia coefficient for the horizontal vibration of ships, three dimensional correction factor $J_H$ for the added mass of finitely long elliptic prismatic bars in horizontal vibration in a free surface of an ideal fluid are calculated. In the problem formulation Dr. T. Kumai's quasi-finite length concept[1,11,12] is employed. Now that, in Dr. Kumai's work[1] for the horizontal vibration the mathematical model was a circular cylinder, the principal aim of the authors' work is to investigate the influence of the beam-draft ratio B/T on $J_H$. The numerical results of this work are shown in Fig.3 graphically, from which we may recognize that the influence of B/T on $J_H$ is remarkable as much as that of the length-draft ratio L/T(refer to Fig.1 also). In Fig.3 the curves for B/T=2.00 are of those based on Dr. Kumai's result[1]. On the other hand, the experimental data obtained by Burril et al.[9] for the horizontal vibration of finitely long prismatic bars of various cross-section shapes are compared with the theoretical added mass coefficients defined by combination of the authors' $J_H$ from Fig.3 and two dimensional coefficients $C_H$ obtained by Lewis form approximation for the corresponding sections. They are in reasonable correspondence with each other as shown in Fig.2. Finally, considering that the longitudinal profile of full-form ship's hull is well resembled to that of an elliptic cylinder and that the influences of other factors such as the sectional area coefficient and the shape of section contour itself can be well merged in the two dimensional added mass coefficient, the authors recommend that the data given in Fig.3 may be successfully adopted for the three dimensional correction factor the added mass in the horizontal vibration of hull-form ships.

• 한국항해항만학회지
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• 제34권10호
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• pp.747-756
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• 2010

본 논문은 해양플랜트 전용거주시설로 사용되고 있는 생활바지선 거주구 공간구성특성에 관한 연구이다. 생활바지선은 Accommodation Work Barge, Accommodation Pipe Lay Barge, Multi-purpose Accommodation Barge로 분류할 수 있다. 이 중 가장 많이 사용되고 있는 Accommodation Work Barge를 대상으로 실적선 GA도면 분석을 통해 거주구 공간구성에 대하여 연구하였다. 거주구 공간구성은 거주자의 생활 편리함과 쾌적성에 큰 영향을 미친다. 생활바지선 거주구 공간구성특성은 수평적 공간배치 보다는 수직방향에 따른 층별 공간배치에 있다. 생활바지선 거주구 공간구성은 '거주공간', '서비스공간', '업무공간'이 층별로 집중되어 나타나는 '집중형'과 각 공간이 층별로 분산되어 나타나는 '분산형'으로 구분된다.

• 한국정보처리학회논문지
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• 제4권8호
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• pp.2152-2162
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• 1997

본 논문은 파이프라인 방식의 ASIC 데이타 경로를 제어하기 위한 시간 정지형 콘트롤러의 자동합성에 관한 연구이다. 콘트롤 합성은 콘트롤 사양의 자동 생성과 유한상태기의 합성 및 최적화 단계로 구성된다. 이 유한상태기는 수평분할 방식을 응용하여 최적화되며 최소 면적의 콘트롤러가 합성된다. 실험을 통해 제안된 방식으로 생성된 콘트롤러와 기존 방식으로 합성된 유한상태기 콘트롤러를 비교하였는데 콘트롤러의 면적에서 있어서 큰 감소를 보여준다.

• 한국정밀공학회지
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• 제17권1호
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• pp.27-33
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• 2000

This paper presents a method for determining machining parameters in 3-dimentional electrical discharge machining(EDM). The parameters are the peak value of currents, the pulse-on time, and the pulse-off time. It is known that they influence the performance of EDM more than the other else. The parameters are determined from the discharge area between a tool electrode and a work piece. The discharge area is directly influenced by the geometry of a tool surface and the tool discharge position. The discharge area on a tool discharge position is calculated from intersection curves between the tool surface and a horizontal plane. The grid search method is applied to determine the intersection curves. An example is introduced to show that the machining parameters are obtained from the surface geometry of a tool electrode.

• 한국건설관리학회논문집
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• 제8권1호
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• pp.87-95
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• 2007

건설공사의 시공공정을 관리자의 경험적 판단에 의하여 작업팀을 구성하여 운영하면, 시공공정의 진행이 비효율적으로 될 가능성이 많다. 그러나 시공계획단계에서 모의조작을 통하여 자원할당, 공사비, 공사기간의 최적 안을 산출하면 시공공정을 정량화하여 효율적인 운영을 할 수 있다. 본 연구에서는 시공공정을 계획할 때 작업팀 운영의 변화에 따른 자원할당 변동치, 자원 손실비, 총공사비, 공사기간의 최적 안을 모의조작 할 수 있는 수식모형의 시안 식을 제안하였다. 제안된 수식모형을 검증하기 위하여 시공공정의 수평작업역과 수직작업 역이 각각 상이하게 구성된 공동주택 골조공사에 적용하여 시현하였다. 본 연구에서 제시된 수식모형을 적용하여 모의 조작을 실시한 결과가 실제 사례공사에서 적용된 작업팀의 운영실적보다 효율화를 달성하였다.

• 수산해양교육연구
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• 제25권3호
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• pp.733-742
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• 2013

The Korea has significant tidal current energy resources, but it is so hard to work underwater for tidal turbine installation. Therefore commercial diving work is very important for tidal current generator. Also, Jangjuk channel is vary famous as proper area to generate tidal current energy. Nevertheless, no one is studied about characteristics of commercial diving works with installation of tidal current generator. The purpose of this study is to introduce commercial diving with work types and investigate critical limits of diving working under the conditions, which are working only to minutes at slack tide during the neap tide. As the results, work types are five as like mooring installation, OMAS(Offshore Maintenance Access System), support structure installation, cable and turbine installation. Here, the original construction period is expected about 4 months, but the construction take 18 months to complete. The cause of extends construction period is insufficiency of researching tidal current conditions at the site and ignorance of slack tide which need to secure diving working time. Total diving working times are 110th during 18 months, the highest percentage of diving times is turbine installation about 43.6 %, and cable, mooring installation and support structure construction are 27.3 %, 15.5 %, 13.6 %, respectively. On the basis of this study, estimation of times of commercial diving is possible with work types of tidal current power, and has a significance as basic data to determining construction period.

• 산업공학
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• 제14권1호
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• pp.95-105
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• 2001

Previous work measurement methods need much time and effort of time study analysts because they have to measure required time through direct observations. In this study, we propose a method which efficiently measures standard times without involvement of human analysts using digital image processing techniques. This method consists of two main steps: motion representation step and cycle segmentation step. In motion representation step, we first detect the motion of any object distinct from its background by differencing two consecutive images separated by a constant time interval. The images thus obtained then pass through an edge detector filter. Finally, the mean values of coordinates of significant pixels of the edge image are obtained. Through these processes, the motions of the observed worker are represented by two time series data of worker location in horizontal and vertical axes. In the second step, called the cycle segmentation step, we extract the frames which have maximum or minimum coordinates in one cycle and store them in a stack, and calculate each cycle time using these frames. In this step we also consider methods on how to detect work delays due to unexpected events such as operator's escapement from the work area, or interruptions. To condude, the experimental results show that the proposed method is very cost-effective and useful for measuring time standards for various work environment.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.89-92
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• 2007

This investigation aims at calculating the geoid height, distance between the ellipsoidal height and the orthometric height by GPS/Levelling data for nationwide 58 Bench Marks, and calculating the effect of geoid height to engineering public works. The accuracy of the results from baseline analyses and adjustment of a network. using GPS surveying data by nationwide 58 BM show 4mm for horizontal direction and 7cm for vertical direction. The 58 geoid height was calculated by GPS/Levelling. For a construction work field GPS/Levelling for distributed 4 BM in test area can calculate the orthometric height in 20 ppm relativity accuracy with 95% reliability. Besides the calculated geoid height in the investigation was 0.367m higher than EGM96 model. The test results of a engineering work site, the result by EGM96 model was 1.8cm in 10km and it was also 3.6cm in interpolation method. The results show that it is equivalent to levelling of $20mm\sqrt{S}$.

• 한국건축시공학회지
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• 제6권1호
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• pp.79-86
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• 2006

Recently, the construction companies show lots of interest in reducing the construction duration of apartment housing project in Korea. Therefore, the purpose of this study is to investigate the success factors of scheduling using the TACT technique in wall type apartment house construction for managing the construction schedule effectively. For appling the tact scheduling technique to wall type apartment house construction, the success factors can be summarized as follows : (1) zoning the horizontal and vortical work area properly, (2) preparing the flow chart of finishing works, (3) minimizing the undefined activity like chipping off the concrete wall, (4) reordering the construction activities for keeping up the continuity of works in winter season, (5) dividing the amount of work for minimizing the delay time of any activity, etc.

• 정보관리학회지
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• 제41권2호
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• pp.185-214
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• 2024

본 연구는 공공도서관의 MZ세대 사서들을 중심으로 일과 삶의 균형이 조직몰입 및 이직의도에 미치는 영향과 조직몰입이 이직의도에 미치는 영향을 분석하고자 하였다. 이를 위하여 수도권 공공도서관에 근무하는 1980년~2005년생 사서 183명을 대상으로 설문조사를 실시하여 일과 삶의 균형의 하위 요인인 일-가족 균형, 일-여가 균형, 일-성장 균형과 조직몰입, 이직의도를 조사하였다. 다중회귀분석 결과, 일-가족 균형, 일-성장 균형은 조직몰입에 유의한 정적(+) 영향을, 이직의도에 유의한 부적(-) 영향을 미치는 것으로 나타났다. 또한, 조직몰입은 이직의도에 유의한 부적(-) 영향을 미치는 것으로 나타났다. 이에 따라 본 연구는 일-가족 균형, 일-성장 균형을 강화하는 정책과 함께 공공도서관의 야간 및 주말 근무에 대하여 정책적인 보상이 필요하다고 제안하였다. 또한, 조직몰입을 강화하기 위하여 수평적인 의사소통과 자율권 강화 등을 제안하였다.