• 한국유체기계학회 논문집
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• 제3권1호
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• pp.19-27
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• 2000

A numerical study is presented for analysis of three-dimensional incompressible turbulent flows in a multi-blade centrifugal fan. Reynolds-averaged Navier-Stokes equations with a standard $k-{\espilon}$ turbulence model are discretized with finite volume approximations. The computational area is divided into three blocks; inlet core, impeller and scroll parts, which are linked by a multi-block method. The flow inside of the fan is regarded as steady flow, and the mathematical models for the impeller forces were established from a cascade theory and measured data. Empirical coefficients are obtained comparing between computational and experimental results for the case without scroll, and are employed to simulate the flow through the impeller with scroll. In comparisons with experimental data, the validity of the mathematical models for the impeller forces was examined. The characteristics of the flow in the scroll were also discussed.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1254-1254
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• 2022

The Multi-family Residential is one of the most famous building types for a rental property in the US. Often times it includes multiple residential buildings and some amenity facilities, including a clubhouse or leasing office, swimming pool, dog park, and garages. Since the building type is built for rental purposes, the construction planning is phased and it makes the project complicated. Detailed planning and execution are important for successful construction management. This paper provides some management practices that are applied to one of the multi-family residential construction projects in Phoenix, AZ. The Front End Planning (FEP) process performed by both owner and contractor is the first key to a successful construction project. Specifically, the early review of phased turnover strategy, grading, fire/Americans with Disabilities Act (ADA) compliance, and Mechanical/ Electricity/Plumbing/Technology (MEPT) will provide absolute benefit to the project. Second, using a scheduling method to control short-term schedules and long-term can provide the ability to manage the issues with agility. Third, material delivery and procurement dominate the both project schedule and cost. With this COVID-19 circumstance, it is hard to expect the material, equipment, and labor forces to be delivered on time with the contracted price. Managing floats are more than important to managing construction productivity. Risk management should work to share the risks fairly. Lastly, turnover is directly linked with the profit of the project for both owner and contractor. The communication between the owner and contractor to re-schedule the proper turnover schedule is important for the phased construction project.

• The Plant Pathology Journal
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• 제17권2호
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• pp.106-109
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• 2001

A multi-rapid immunofilter paper assay (multi-RIPA) system was prepared for simultaneous diagnosis of three Tobamoviruses, Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), and Zucchini green mottle mosaic virus (ZGMMV) in cucurbitaceous crops. Each of these viruses was specifically detected by the multi-RIPA from cucumber, watermelon, zucchini, and bottle gourd inoculated with the three Tobamoviruses singly or in combination. The three viruses could infect cucumber, watermelon, and bottle gourd ; however, CGMMV could not infect zucchini as the latex-coated CGMMV antibody showed a negative reaction in the multi-RIPA of the virus-infected plant extract. When the minimum detection level of multi-RIPA was compared with that of double antibody sandwich-enzyme-linked immunosorbent assay (DAS-ELISA) using CGMMV, the latter was 10 times more sensitive than the former. The detection limit of the multi-RIPA for the purified CGMMV was 50 ng/ml. In a survey of the threeviruses in cucurbits growing in commercial fields in 1999 and 2000, CGMMV was detected in watermelon and cucumber, and ZGMMV was detected only in zucchini growing in plastic houses at the suburbs of Chonju, Korea. However, KGMMV was not found in the commercially growing cucurbit crops in our study, The results suggest that the multi-RIPA can be a simple, rapid, specific and convenient tool to detect simultaneously the Tobamoviruses.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.869-872
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• 2001

A new in-pipe locomotive mechanism is developed using piezoelectric bimorphs. Two bimorphs are linked serially and produce an ellipsoidal motion at the end of bimorph. The device moves by the friction force between the rubber attached at the bimorph end and the inner surface of the pipe. The developed mechanism is very simple and need relatively small power compared to a conventional multi-layer piezoelectric motor.

• 한국정밀공학회지
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• 제12권10호
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• pp.18-24
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• 1995

This paper describes a multi-computer system developed for CIM(Computer Integrated Manufacturing) system, which combines single board computers and personal computers by using RS422/485 communication and LAN. The system adopts a concept of hot run back up system based on dual CUP system of host and supervisor structure. The dual CPU system and the single board computer are respectively developed using 32 bits microcomputer and 16 bits microprocessor. 8097BH. The multi communication between two types of system is done by using RS 422/485, and also data logging computers are linked with LAN.

• 한국통신학회논문지
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• 제21권8호
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• pp.2033-2042
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• 1996

In this papre, we describe a recently implemented echo canceller for digital cellular communication of Code Division Multiple Access(CDMA) that features time sharing of digital signal processor(DSP) over four channels in one DSP to reduce per channel costs. In the Public Land Mobile Network(PLMN), it is important to cancel the echo reflected from the Public Switched Telephone Network(PSTN) side. In case of digital mobile system, the round-trip delay of the echo is in excess of about 180 milliseconds due to frame-by-frame voice coding. It is necessary to cancel the echo in PLMN. We have developed a multi-channel echo canceller tht operates with Time Switch Module in a Mobile Switching Center(MSC). The general echo canceller needs PCM trunk interface circuits and the tone detection and disabling circuits, but the multi-channel echo canceller linked with Time Switch Module does not need them. Therefore we could develop the effective and economical echo canceller.

• Wind and Structures
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• 제4권6호
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• pp.495-504
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• 2001

With a newly developed multi-force-balance system(MFB), a twin-tower structure was studied for its wind-induced responses. The MFB system allowed the twin towers, which were linked structurally, to be treated as a single structural system with its corresponding modes of vibration involving coupled motions of the two towers. The towers were also studied using a more conventional force balance approach in which each tower was treated as an isolated structure, i.e., as though no structural link existed. Comparison of the results reveals how the wind loads between the towers are redistributed through the structural links and the modal couplings. The results suggest that although the structural links usually have beneficial impacts on wind-induced response, they may also play a negative role if the frequency ratios of pair modes are near 1.0.

• 한국시뮬레이션학회논문지
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• 제11권1호
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• pp.59-70
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• 2002

This article presents the results of research to develop a descriptive model of firm-level productivity that will allow a myriad of factor interactions to be directly accounted for. The model is a linked set of equations that attempt to capture how changes in one-factor influences the level of another factor. and ultimately bottom-line performance. The model is coded in SIMAN. It is used to determine the best use of an infusion of funds should they go for additional automation, or training etc. An application of the model to U.S. industry is presented based on parameter values obtained through a national survey.

• 항공우주시스템공학회지
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• 제15권6호
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• pp.72-77
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• 2021

This paper proposes a design and development plan for a control program for the MX-10 EO/IR camera. This camera is a piece of mission equipment mounted on the multi-purpose unmanned helicopter (MPUH) system. Operators must be able to control the necessary functions of the camera to perform their assigned tasks. To achieve this, the function to control the camera was analyzed, and a control program was developed. In addition, the control program was linked to a joystick for convenient operation of the camera by the operator.

• 디지털융복합연구
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• 제15권10호
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• pp.243-251
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• 2017

효과적인 데이터 분석 및 활용을 위해서는 빅 데이터를 내부 데이터와 유연하게 연계할 수 있는 방안이 필요하다. 빅 데이터 분석 정보를 내부 정보시스템과 연계시키기 위한 방안으로서 본 연구는 다차원 이벤트 온톨리지를 제시하였다. 이를 위해서 먼저 빅 데이터 분석 정보를 이벤트 모형을 사용하여 온톨리지로 표현하고, 다차원 데이터베이스 또한 OWL-DL 온톨리지로 변환하여 표현하였다. 다차원 이벤트 온톨리지에서 빅 데이터 분석정보들은 차원 계층구조를 통하여 다차원 데이터베이스에 저장된 모든 개체들에게 공유되는데, 본 연구에서는 이를 이벤트의 하향공유, 상향 공유 및 복합 이벤트 공유로 구분한다. 이들 정보공유 유형별로 빅 데이터 분석 정보의 공유 및 활용 방안들을 제시하였으며, Protege를 사용하여 시험적으로 구현하였다. 본 연구는 외부의 빅 데이터 분석 정보를 내부의 다차원 데이터베이스와 연계하는 방안을 실험적으로 제시하였다는 점에서 의의를 가진다고 할 수 있다.