• 대한의용생체공학회:의공학회지
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• 제12권4호
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• pp.309-314
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• 1991

This paper describes the results of study on the measurement method of TRMS (true root mean square value) In electrosurgical unit. We used three type (direct computing type, indirect computing type, thermal converting type) in the measurement of TRMS. Three types of measurement method were compared with respect to power level, frequencey and crest factor in addition to environmental temperature. In three of them, the thermal converting type was the best for th electrosurgical unit analyzer

• Korean Journal of Mathematics
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• 제31권2호
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• pp.229-242
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• 2023

In this paper, we investigate the [p, q] - φ order and [p, q] - φ type of f₁ + f₁, ${\frac{f_1}{f_2}}$ and f₁ f₁, where f₁ and f₁ are analytic or meromorphic functions with the same [p, q]-φ order and different [p, q]-φ type in the unit disc. Also, we study the [p, q]-φ order and [p, q]-φ type of different f and its derivative. At the end, we investigate the relationship between two different [p, q] - φ convergence exponents of f. We extend some earlier precedent well known results.

• 한국실내디자인학회논문집
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• 제13권5호
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• pp.90-97
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• 2004

The purpose of this study is to grasp the spatial characteristic of the unit plan for a Super-High-Rise-Residence. This study is focused on the open air contact sides for a tower type Super-High-Rise-Residence. A tower type Super-High-Rise-Residence which has open air contacts from 1 to 3.5 sides differed in spatial characteristics of the unit plan for other apartment units. The current study analyzed 188 unit plans for the size of 40 pyong or larger in Seoul and the metropolitan areas which have been built since 1990. Open air contact side was classified as under 2 sides, 2 sides, and over 2 sides. The unit plan which belong to each open air contact side was Investigated according to the location of public area, the relationship between livingroom and master bedroom, and a method of entry to the master bedroom. The results of this study are as follow: According to increase open air contact sides is changed the location of public area in unit plan from an typical arrangement to various arrangement. Also the relationship between livingroom and master bedroom becomes loose and in a method of entry to the master bedroom increase an indirect approach through other room.

• Industrial Engineering and Management Systems
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• 제9권2호
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• pp.121-130
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• 2010

In today's uncertain economic environment, economic risk is inherent in making large investments on manufacturing facilities. It is, therefore, practically meaningful to divide investment over multiple periods, reducing the risk of investment. Then, the cash-flow over the entire planning horizon would comprise positive inflow and negative outflow. In this case, in general, evaluation by internal rate of return (IRR) is not feasible, because multiple IRRs are involved. This paper deals with a problem of evaluating profitability, as well as risk, of investment alternatives made in multiple times of investment over the entire horizon. Typically, an additional investment is required after the initial one, for expanding manufacturing capacity or other reasons. The paper pays attention to a unit cash-flow over two periods, decomposing the total cash-flow into a series of unit cash-flow patterns. It is easy to evaluate profitability of a unit cash-flow by using IRR. The total cash-flow can be decomposed into the series of two types of unit cash-flows: an investment type one (negative-positive) and the borrowing type one (positive-negative). This paper, therefore, proposes a method in which only the borrowing type unit cash-flow is eliminated in the series by converting total cash-flow using capital interest rate. Then, a unique IRR can be obtained and the profitability is evaluated. Thus, the paper extends the method of IRR so that it may help decision making in complicated cash-flow pattern observed in practice.

• International Journal of Precision Engineering and Manufacturing
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• 제2권1호
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• pp.43-55
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• 2001

A continuously variable transmission(CVT) mechanism composed of one differential gear unit and one continuously variable unit(CVU) can be classified according to the coupling of CVU and the direction of power flows. The mechanism has many advantages which are the decrease of CVT size, the increase of overall efficiency, the extension of speed ratio range and generation of geared neutral. The CVT mechanism considered here is the input coupled type which combines the functions of a 2K-H I type differential gear unit and a V-belt type CVU. One shaft of the CVU is connected directly to the input shaft and another shaft of it is linked to the differential gear unit. It is shown that some fundamental relations(speed ratios, power flows and efficiencies) for twelve mechanisms previously described are valid by various experimental studies, six of them produce a power circulation and the others produce a power split. Some useful comparisons between theoretical analysis and experimental results are presented. General properties also are discussed, which connect following power flow modes : (a) power circulation mode; (b) power split mode.

• 한국실내디자인학회논문집
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• 제19권1호
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• pp.180-189
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• 2010

Since collective houses are started to be supplied, the housing market has been transformed from supplier to demander oriented, and various type with same area of unit households have been deigned and started to be distributed. It can be expected that such transfer phenomenon would be continuously sped-up, and unit household will be more subdivided and varied. Thus, we analysed and studied the planes with subject of unit households in national housing scale ($85m^2$) that is treated as supply standard and has biggest volume in construction by Korean housing corporation. The analysing method is investigating the area of each room within unit household, calculating their minimum, maximum, and average values, studying the efficiency of unit household plane according to the structure of each room by comparative analysis these values, and analysing changing matter by investigating any change of each room area. The analysing results of which are followings. At first, number of BAY on face is increasing. Second, allocation of each room has been vary. Third, area ratio among bedroom1, livingroom, diningroom/kitchen become similar. Fourth, the area of diningroom/kitchen become somewhat bigger. Fifth, the space for passage way is efficiently allocated. Sixth, service area is reduced, Seventh, stereotyped phenomenon Is appeared. Based on many studies so far, any improvements of unit householder in national housing scale are followings. First, in terms of forming style, unit householder in national housing scale is unfolded in various way though, the form of each room is not more than typical style. Second, it shows stereotyped phenomenon. Especially, bathroom 1, 2 show stereotyped feature in terms of their type and area across entire research years, also LDK allocation method is stereotyped, as well as stereotyped trend in bedroom 2, 3, allocation for 4 BAY type.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.439-444
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• 2005

Steady state simulation and dynamic simulation were performed to analyze the operational characteristics of a multi-type refrigeration system, Fully distributed model was adopted to simulate the steady state and transient responses of the system. The main aim was to see the effect of one indoor unit on the other unit. Numerical simulations were carried out for various operation conditions of an indoor unit - secondary fluid inlet temperature, mass flow rate and expansion valve opening. The results showed that the inlet temperature and mass flow rate of the secondary fluid of one indoor unit had minor effect on the operation of the other unit. However, the opening of the expansion valve had significant effect on the performance of the other unit.

• 대한기계학회논문집A
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• 제26권6호
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• pp.1060-1068
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• 2002

Compound continuously variable transmission(CVT) mechanisms are proposed, which can offer a backward mode, a geared neutral, an underdrive mode and an overdrive mode. They are composed of a 2K-H I type differential gear unit, a V-belt type continuously variable unit(CVU), a few friction clutches and gears, and not required of a starting device as a torque converter. Compound CVT mechanisms developed here present two distinct operating modes which are a power circulation mode and a power split mode. The transition of two modes takes place at the particular CVU speed ratio. For these CVT mechanisms, performance analysis related to speed ratio, power ratio and efficiency are executed and proven by experimental studies.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.111-118
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• 2006

The Emergency Diesel Generator(EDG) is a very important piece of equipment for the safety of a Nuclear Power Plant(NPP). In this study, the operating vibration or three kinds or EDG system was measured. The target EDG systems art Yonggwang 5 unit, Ulchin 2 unit and Ulchin 3 unit. The Yonggwang 5 and Ulchin 3 unit EDG system is the same type but the foundation systems are different. One is an anchor bolt type and the other is a spring and viscous-damper type. The purpose of this measurement is for a verification of the vibration isolation effect according to the foundation system. As a result. it can he said that the spring and viscous damper system of the EDG performed well for the vibration isolation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.205-208
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• 2002

An existing ATM switch fabric uses VPI(Virtual Path Identifier) and VCI(Virtual Channel Identifier) information to route ATM cell. But AAL type 2 switch which efficiently processes delay-sensitive, low bit-rate data such as a voice routes the ATM cell by using CID(Channel Identification) field in addition to VPI and VCI. In this paper, we research the AAL type 2 switch that performs the process of CPS packet. The Receive unit extracts the CPS packet from the inputted ATM cell. The designed receive unit consists of input FIFO, r)( status table, CAM(Content Addressable Memory), new CID table and partial packet memory. Also the designed receive unit supports the PCI interface with host processor. The receive unit is implemented in Xilinx FPGA and operates at 72MHz.