• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.231-239
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• 2006

An experimental investigation of a Reversible Loop Heat Pipe (RLHP) was conducted to determine the operating limits and performance characteristics as functions of the thermophysical parameters, the heat input, and the cooling intensity. Variations in both temperature and heat transport capacity were measured and analyzed in order to accurately evaluate the transient operating characteristics. In addition, the maximum heat transport as a function of the mean evaporator temperature, the ratio of heat transport to heater input power as a function of the mean evaporator temperature, and the overall thermal resistance as a function of the overall heat transport capacity were examined as well. Results indicated that the cooling intensity played an important role on the operating characteristics and performance limitation. The maximum heat transports corresponding to cooling intensity $72W/^{\circ}C$ and $290W/^{\circ}C$ were 446 W and 924 W, respectively. Also, observation of the startup characteristics indicated that the mean evaporator temperature should be maintained between $40^{\circ}C$ and $60^{\circ}C$, and overall thermal resistance were measured as $0.02^{\circ}C/W$.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.72-79
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• 2006

The objective of this work is to simulate the etching characteristics for the optimization on the etching process of Lead-Frame. The etching characteristics such as etching factor, etching uniformity were investigated under different the actual operating conditions. The correlation between the etching characteristics and the spray ones were analyzed to simulate the etching characteristics in the etching process. To improve the etching characteristics in the etching process, effects of the various operating conditions such as pressure, distance from nozzle tip, pipe pitch, and feed speed should be understood in detail. The spray characteristics obtained by experiment using PDA system were simulated by the Monte-Carlo simulation. The etching process model was coded by Java language. It was found that the spray characteristics were correlated with the etching ones and simulation results generally agreed well with the measured results of etching characteristics in the etching process of Lead-Frame. The optimal operating parameters were successfully found under variable conditions.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.131-134
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• 1991

In order to determine an operating pattern of SLIM in an experimental MAGLEV vehicle, operating characteristics of SLIM are obtained using a disk type test facility. The test results are compared with the pre-estimated values. It is found that a closed loop control is required for operating at a constant slip-frequency condition which makes the normal force minimum.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.260-267
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• 2013

A combat system for navy's battleship is a system of systems who supports naval indigenous operations by integrating and inter-operating many different kind of weapon and non-weapon systems, which has characteristics of large-scale complex computing system. This paper considers a characteristics of naval combat system which has been developed by domestic technology and suggests a way to improve future naval combat system in terms of computing architecture by applying commercial real-time operating system technologies. This paper also provides an evaluation criteria for combat system adaptability of real-time operating systems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.71-77
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• 2009

Using the results of the expected busy periods for the dyadic Min(N, D) and Max(N, D) operating policies in a controllable M/G/1 queueing model, an important relation between them is derived. The derived relation represents the complementary property between two operating policies. This implies that it could be possible to obtained desired system characteristics for one of the two operating policies from the corresponding known system characteristics for the other policy. Then, upper and lower bounds of expected busy periods for both dyadic operating policies are also derived.

• Journal of Korean Biological Nursing Science
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• v.23 no.1
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• pp.43-54
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• 2021

Purpose: This study aimed to identify the factors influencing infection-related characteristics and patient safety culture on awareness of blood-borne infection prevention between operating room nurses and general ward nurses. Methods: Participants were 198 nurses(operating room nurses 98 and general ward nurses: 100) working at three general hospitals and three university hospitals in three cities. Data were collected using a structured questionnaire from September 11 to October 14, 2020. Data were analyzed using descriptive statistics, t-tests, ANOVA, Pearson's correlation coefficient, and multiple regression with IBM SPSS/WIN 26.0 program. Results: Typically, 39.8% of nurses in the operating room and 24.0% of ward nurses experienced injuries such as needles and sharp instruments used by the patient. The awareness of patient safety culture was identified to be higher for the ward nurses. Factors influencing the awareness of blood-borne infection prevention in operating room nurses were patient safety culture and wearing protective equipment for infection prevention while nursing infected patients. Moreover, the explanatory power of these variables was 19.4%. In general ward nurses, the patient safety culture was identified as a significant predictor, which accounted for 16.5% of awareness of blood-borne infection prevention. Conclusion: To prevent hospital infection, a strategy is needed to improve the level of awareness of blood-borne infection prevention and patient safety culture of operating room nurses. To this end, the difference in infection-related characteristics and influencing factors between the operating room nurses and the general ward nurses should be considered and planned.

• The KSFM Journal of Fluid Machinery
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• v.9 no.6 s.39
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• pp.54-62
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• 2006

An experiment about performance characteristics is conducted on a double chamber vane-type rotor. Three different rotors, which have 6, 8 and 9 vanes, are applied to the driver and various lift holes at the rear plate are used to increase the effective vane height. The inner diameter of a double chamber cylinder is ${\phi}27mm$, and the length of the cylinder is 65 mm. The maximum offset length between the rotor outer surface and the cylinder inner surface is 4.5 mm. In this study, specific output torques and powers are measured, and also noise and vibration are measured at the real operating situation. The operating torque on the double chamber is increased to 17% compared to the operating torque obtained at the single chamber which has the same size. The experimental results of noise and vibration show that the operating sound and vibration are directly related to the operating power generated by the double chamber rotor.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.2
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• pp.97-104
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• 2005

Usually, propagation attenuation of millimeter wave occurs by rainfall, snowfall, temperature, effect of pressure of air. In 60GHz wave band wireless communication network, temperature change becomes big factor of propagation loss department. Also, temperature change causes disturbance of 60GHz frequency at transceiver. In this study, we used 60GHz transceiver and found propagation loss of wireless path and operating frequency disturbance characteristics. In transceiver that there is no temperature compensated device, operating frequency of TX changed by 60.865GHz at temperature of $-5^{\circ}C$, and appeared by 60.730GHz when is $50^{\circ}C$. Therefore, operating frequency change width by temperature change are about 100MHz, greatly. But, in transceiver that there is temperature compensated device, operating frequency of TX changed by 60.830GHz at temperature of $-5^{\circ}C$, and appeared by 60.710GHz when is $50^{\circ}C$. Therefore, operating frequency change width by temperature change are about 20MHz. According to these result, we constructed between buildings examination wireless site for point to point wireless communication using 60GHz band transceivers who have do temperature compensated device, and investigated data transmission characteristics about ambient temperature change. Therefore, if use transceiver that have temperature compensated device, may overcome the wireless transmission error in 60GHz band wireless communication LAN networks despite of ambient temperature change.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.6
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• pp.44-49
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• 2003

The morphological analysis of wear debris can provide early a failure diagnosis in lubricated moving system. It can be effective to analyze operating conditions of oil-lubricated tribological system with shape characteristics of wear debris in a lubricant. But, in order to predict and recognize an operating condition of lubricated machine, it is needed to analyze and to identify shape characteristics of wear debris. Therefore, If the morphological characteristics of wear debris are recognized by computer image analysis using the neural network algorithm, it is possible to recognize operating condition of hydraulic driving members. In this study, wear debris in the lubricating oil are extracted by membrane filter (0.45$\mu\textrm{m}$), and the quantitative values of shape parameters of wear debris are calculated by the digital image processing. This shape parameters are studied and identified by the artificial neural network algorithm. The result of study could be applied to prediction and to recognition of the operating condition of hydraulic driving members in lubricated machine systems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.96-103
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• 2014

A steady-state controllable M/G/1 queueing model operating under the (TN) policy is considered where the (TN) policy is defined as the next busy period will be initiated either after T time units elapsed from the end of the previous busy period if at least one customer arrives at the system during that time period, or the time instant when Nth customer arrives at the system after T time units elapsed without customers' arrivals during that time period. After deriving the necessary system characteristics such as the expected number of customers in the system, the expected length of busy period and so on, the total expected cost function per unit time in the system operation is constructed to determine the optimal operating policy. To do so, the cost elements associated with such system characteristics including the customers' waiting cost in the system and the server's removal and activating cost are defined. Then, the optimal values of the decision variables included in the operating policies are determined by minimizing the total expected cost function per unit time to operate the system under consideration.