• Journal of Biosystems Engineering
• /
• v.12 no.1
• /
• pp.6-13
• /
• 1987

A mathematical model for the waste heat recovery system for an engine was developed. The model based on the experimental data reported before was validated and was used to predict the waste heat recovery and recoverable heat of the engine at various operating conditions of the engine and the system. The model was also used to determine flow rates of the circulating water in the system for a certain temperature increment of the water at various operating conditions of the engine to give basic data to design the system. Stability of the system performance was tested on subjects of vapor lock problem, thermal characteristics of the thermostatic valve, and temperature variation of the circulating water in the engine and fuel consumption of the engine during each mode of the system operation and its change into the other. The test showed that the system operation was stable enough. Temperature profile in the thermal energy storage (TES) was observed during storing thermal energy, and thermal stratification in the TES was well formed acceptable to be used in the system. Finally a scheme to automatize the system was suggested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.399-401
• /
• 2014

The comprehensive vibration assessment program(CVAP) of APR+ nuclear power plant(NPP) is classified as non-prototype, category II with Palo Verde NPP as valid prototype. In this paper, CVAP for first plant of APR+ NPP is proposed. The Control Element Assembly(CEA) shroud of APR+ NPP is different from that of Palo Verde NPP. And the Core Support Barrel(CSB) outer diameter and the flow rate of normal operation of APR+ NPP are larger than those of Palo Verde NPP. Vibration and stress analysis program should be conducted to establish test acceptance criteria. Limited vibration measurement program should be implemented to establish the margin of safety, demonstrate the satisfaction of test acceptance criteria and confirm the similar vibratory response between the APR+ and Palo Verde NPP. Because of the change of normal operation condition, the nominal differences between APR+ and Palo Verde NPP in the structural and hydraulic analysis are studied to determine the measurement locations.

• Journal of Biosystems Engineering
• /
• v.28 no.6
• /
• pp.497-504
• /
• 2003

The objectives of this study were to develop a harvesting gripper for perilla leaves and test its performance, which was a partial work of the automated perilla leaves harvesting system development. The results of this study could be summarized as the followings: The shear forces for harvesting the perilla were measured. The measured results showed that the average shear force required was 12.13N for cutting the petioles attached to the perilla stalks, and the maximum of 17.42N. The inner diameter of air cylinder used was 6mm and the air pressure was maintained as 0.7㎫ during the tests. The time required for cutting perilla leaves could be adjusted by the control program and cutting operation could be done within 1- 10 seconds. The performance tests were conducted to harvest the perilla leaves by the gripper developed. The average success rates of cutting were 72.2％ for the first test, 78.5％ for the second, and 74.2％ for the last. The perilla leaves were not damaged by the gripper The whole system operation could be finished within three seconds except the delay time for dropping harvested leaves.

• Journal of the Ergonomics Society of Korea
• /
• v.28 no.3
• /
• pp.27-31
• /
• 2009

To evaluate the usability of a Kimchi refrigerator, we performed an evaluation test that consisted of an experiment and a post-hoc questionnaire survey. In this study, we focused on the older women who have less physical and cognitive ability than younger women. In physical usability, there was no significant difference between the older and the younger subject group. However, there was some significant statistical difference in the results of cognitive usability test. When the subjects debriefed their operations after finishing the experiment, the all subjects in the older group reported the difficulties in identifying the labels and icons in the control panel and in understanding operation sequences. Also, they couldn't learn and remember the operation procedures well. Based on the analysis of the video protocols, some causes of the problems were found and then several improvement ideas were suggested.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.11a
• /
• pp.656-657
• /
• 2010

The ground oxidizer supply system in the launch site of NARO space center had operated 9 times from the start of tests with ILV on May, 2009 to the 2nd flight test of the NARO vehicle. This system operated successfully for twice launches of the NARO vehicle. To judge the successful operation of the ground facility, it should have reproducibility and reliability. In this report, we have analyzed the liquid oxygen consumption of the system to judge of its reproducibility and it can be a reference for using this system for the next generation of KSLV system.

• Proceedings of the KSME Conference
• /
• 2008.11b
• /
• pp.2434-2439
• /
• 2008

This paper was studied on the cavitation instability of a Solution Pump Inducer in an absorption chiller-heater. Inlet pressure of LiBr and rotational speed at nominal mode are 2,800 Pa and 3,500 rpm respectively. Due to the marginal operation of available NPSH, the cavitation performance of the inducer is critical for the stable operation without the deterioration of head performance. In the study, cavitation performance and its mode of instability was investigated experimentally. Water was used as the working fluid and the test inducer was scaled up as 1.75 times for detail measurements and flow visualization. Inlet pressure was controlled by a vacuum pump. This research focused on types of cavitation instability and phenomena to investigate the possibility of harmful damage due to cavitation instability. Casing wall pressure and instantaneous inlet pressure was measured to observe the unsteady flow characteristics. Through the visualization and spectrum analysis of pressure, the occurrence region and intensity of asymmetric cavitation and cavitation surge are analyzed in the test inducer.

• Journal of the Ergonomics Society of Korea
• /
• v.25 no.3
• /
• pp.97-103
• /
• 2006

Severities of musculoskeletal diseases (MSDs) have been recognized at the regular work such as manufacturing but incidence of MSDs are increasing also at the atypical work. The examples of those are health medical workers, office workers and service workers etc. Nurses among health medical workers are accomplishing to manage and recover the patients' health in the first place. Therefore, they are exposed to very stressful work conditions during caring the patients. This study was performed to analyze the musculoskeletal burdened work among nurses at a university hospital, in order to grasp the realities of the MSDs, analyze and prevent MSDs. We surveyed risk factors for ward, intensive care unit, delivery room, newborn room, operation room, function test room and central supply room at a university hospital in Seoul. It was executed for 2 months as the field study that was composed of simulation, real measurement, work motion assessment and subjective assessment. And the results were analyzed into ergonomics techniques. Works according to the criteria of musculoskeletal burdened work by the Ministry of Labor were scrub in operation room and heart ultrasonic function test. And a lot of works that need attention and management were also detected. So it should be required the education and systematic managements of MSDs for nurses.

• Journal of Korean Academy of Nursing Administration
• /
• v.10 no.3
• /
• pp.345-364
• /
• 2004

Purpose: This is develop a critical pathway as an useful alternative to the previous management system in order to restriction of medical resources, high expectation of ordinary people to health and application for DRG. Method: In order to preliminary critical pathway, we analyzed 30 cases of medical records of patients who had lobectomy and pneumonectomy at the Yonsei Medical Center in Seoul. An expert validity test was taken for the preliminary critical pathway, and clinical validity test was also done. After these processes, the final critical pathway was developed. Result: Among 10 cases, one was excluded in this study due to the complication after operation. 7 of total 9 patients were discharged earlier than the expected day, 1 patient was just discharged at the expected day, and 1 patient was discharged 4 days later than the expected day at the 12th day after operation. Conclusion: The critical pathway is developed without difficulty because the posoperative management for patients with lobectomy and pneumonectomy is uncomplicated. Therefore, if it is more researched on the clinical application, then the activity of C.Q.I. will be able to sustain the patient oriented management system.

• Nuclear Engineering and Technology
• /
• v.38 no.8
• /
• pp.785-792
• /
• 2006

The microwave heating system of KSTAR consists of ECH and LHCD. ECH and LHCD offer the benefits ofa reliable operation at the start of plasma formation and a non-inductive current drive durable steady state operation, respectively. LHCD uses a C-band microwave system with a frequency of 5 GHz. A pulsed power modulator with a power of 3.6 MW, $4{\mu}S$, 200 pps is required to drive the high-powered magnetron. The development of a pulse modulator with 1:4 pulse transformers is the focus of the research in this study. The peak power handling capability is 3.6 MW (45 kV, 90 A at load side with a pulse width of $4{\mu}S$). This paper describes the system overview and test results of the pulsed modulator. In particular, a simulated waveform is compared with the tested waveform.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.19 no.1
• /
• pp.84-94
• /
• 2016

The warfighting experimentation is the most important for the weapon acquisition process because the warfighting experimentation shall support the operation effectiveness as well as acquisition logicality. Therefore, ROK Navy is starting to set up the next generation warfighting experimentation systems. According to literature studies, there have been many studies regarding the interoperability of Simulators(Virtual) and Exercising models(Constructive), but not for studies regarding interoperability between Simulators(Virtual) and Analysis models(Constructive) that is the core component of next generation maritime warfighting experimentation systems. This study is dealing with the V-C(Analysis model) interoperability test and methodology of interoperation analysis. The purpose of the study is to provide the new analysis methodology through V-C(Analysis model) interoperation, which can be applied for the concept of operations(CONOPS) of next generation maritime warfighting experimentation systems. In addition to that, the study validates the suggested analysis methodology by the case study of a naval operation.