• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1306-1311
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• 2006

The root cause of abnormal sound from a heat exchanger of condensate water system in a nuclear power plant is investigated by using the impact signal-processing methodology based on the Hertz theory. The predicted results for the location of impact force and the loose part size meet good agreement with the identified materials during the overhaul period in the plant. Nuclear power plants have experienced several loose parts and the frequency of the loose part will be increased along the aging of the plants. So, this analysis methodology for the impact signal will be widely utilized for the primary and secondary side of the nuclear power plant.

• Journal of Biosystems Engineering
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• v.22 no.1
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• pp.41-48
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• 1997

A nondestructive quality inspection technique using acoustic impulse response method was studied to investigate the feasibility of egg shell inspection. An experimental system was built to generate impact force, to measure the response signal and to analyze the frequency spectrum. This system includes an impulse generating unit, an egg holding seat, a microphone with preamplifier, and a digital oscilloscope connected to Personal Computer by RS-232C interface. The factors such as impulse generating method, egg holding method, and sensor location were evaluated by analyzing the power spectrum density of the measured signal. The results obtained are summarized as follows : 1. From the sampled eggs, the proper conditions for detecting damaged eggs were found as followings; ceramic for the impact ball material, rubber for egg seat material, 20 degrees for an impact angle of pendulum, 10mm for the distance between egg and sensor, the sharp side for impacting part, and 180 degrees for the location of sensor. 2. Examination of the Fourier transformed analysis in beth normal and damaged eggs revealed that those factors such as the resonant frequency, a number of peak frequencies and the magnitude of power spectrum were important to detect damaged eggs.

• Journal of Auto-vehicle Safety Association
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• v.8 no.3
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• pp.5-9
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• 2016

The objective of this study was to find the factors affecting the results of full frontal barrier impact test for the NCAP (New Car Assessment Program). To find the factors, the frontal NCAP test results of the NHTSA (National Highway Traffic Safety Administration) were utilized. The three tested vehicle were same model year. It was observed the second peak value of barrier force affected the occupant injury risk. As the second peak value of the barrier force increases, the injury risk of the driver side occupant increases as well.

• KDI Journal of Economic Policy
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• v.43 no.1
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• pp.29-52
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• 2021

The purpose of this paper is to measure the impact of the recent Korea-Japan trade dispute on the Korean economy using supply-driven input-output analysis. In July 2019, Japan announced the decision to tighten the export control of three materials which are indispensable in the manufacturing of semiconductors and electronic display panels. Japan's decision directly affects production in Korea's semiconductor and display sectors and is hence not a demand shock. For this reason, a standard demand-driven input-output analysis is not valid despite the fact that it can still be applied. The impact of Japan's decision on Korea's aggregate and individual sectors' gross output, GDP and employment were computed using both methods.

• The Transactions of the Korea Information Processing Society
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• v.13 no.6
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• pp.278-283
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• 2024

When implementing software, there can be side effects that pose a threat to human life. Therefore, it is necessary to measure the impact of software on safety and create alternatives to mitigate and prevent threats. To conduct a software safety assessment to measure the impact of threat factors, the following components are necessary. This paper aims to classify the threat factors of software into internal and external factors and quantitatively demonstrate the impact of these threat factors.

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.945-953
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• 2014

This study aims to develop protective pants to relieve impact from falls and to present basic data for the development. The survey results are as follows; First, 45% of the respondents were in their 60s and 55% of them were in their over 70s and older. Also, 64% of them have fallen once for the past year and 36% of them have fallen twice or more. The older they were, the more there were those who have fallen twice or more. This indicated the older people has experienced more fall accidents again after a initial fall accident. Second, as per accident situations, the survey showed that fall accidents happened the most in the winter and in the afternoon (12-18 pm). Also, it happened on a street mostly and they were wearing sneakers or hiking boots when they got a hurt slipped in a front or side by missing their step in a walk. The injury areas are mostly knee and ankle. They had the bruises or a sprain in their knee and ankle mostly. The rate of bone fracture was 19.5%. Therefore, the protection area to falls in lower body is the knee. But hip and hip joint should be protected with knee as well because those are usually be broken when it is damaged. Third, approximately 80% of those who were hospitalized for treatment had surgery. Patients who had surgery were rather in their over 70s than in their 60s. The older they were, the more serious their fracture was. The period of hospital or outpatient treatment is more than three weeks in many cases. They responded their health got worse after falls. Aftereffects of accidents were physical discomfort, anxiety and medical costs. Falls to the old makes physical damage, psychological damage, which cause reduced physical activity and the increased cost of health care with economic losses. So it results on a negative impact on the life of the old. Fourth, elderly females were rarely aware of impact protective clothing and they have never purchased such clothing. For impact protective pants, the major consideration was suitable design for their body types. They liked casual style with front or side pockets and simple designs without any patterns or decorations. As per pants materials, they responded that they need functionality, activity and elasticity. Among the functional points, insulation of cloths are considered importantly, so the heat reservance of material in the impact protective pants should be considered carefully.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.3
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• pp.146-153
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• 2006

We have been investigating InGaAs HEMTs as a future high-speed and low-power logic technology for beyond CMOS applications. In this work, we have experimentally studied the role of the side-recess spacing $(L_{side})$ on the logic performance of 50 nm $In_{0.7}Ga_{0.3}As$ As HEMTs. We have found that $L_{side}$ has a large influence on the electrostatic integrity (or short channel effects), gate leakage current, gate-drain capacitance, and source and drain resistance of the device. For our device design, an optimum value of $L_{side}$ of 150 nm is found. 50 nm $In_{0.7}Ga_{0.3}As$ HEMTs with this value of $L_{side}$ exhibit $I_{ON}/I_{OFF}$ ratios in excess of $10^4$, subthreshold slopes smaller than 90 mV/dec, and logic gate delays of about 1.3 ps at a $V_{CC}$ of 0.5 V. In spite of the fact that these devices are not optimized for logic, these values are comparable to state-of-the-art MOSFETs with similar gate lengths. Our work confirms that in the landscape of alternatives for beyond CMOS technologies, InAs-rich InGaAs FETs hold considerable promise.

• Imaging Science in Dentistry
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• v.43 no.1
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• pp.25-30
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• 2013

Purpose: This study was performed to determine the prevalence of bifid mandibular condyles (BMCs) in asymptomatic and symptomatic temporomandibular joint (TMJ) subjects with no traumatic history, and to assess their impact on clinical and radiographic manifestations of TMJ. Materials and Methods: A total of 3,046 asymptomatic and 4,378 symptomatic patients were included in the study. Cone-beam computed tomography (CBCT) images were reviewed for bifid condyles. T-tests were used to compare the frequency of BMCs when stratified by symptom, gender, and side. In BMC patients, the clinical features of pain and noise, osseous changes, and parasagittal positioning of the condyles were compared between the normally shaped condyle side and the BMC side using chi-squared tests. Results: Fifteen (0.49%) asymptomatic and 22 (0.50%) symptomatic patients were found to have BMCs. Among the bilateral cases, the number of condyles were 19 (0.31%) and 25 (0.29%), respectively. No statistically significant differences were found between asymptomatic and symptomatic patients, between female and male patients, or between the right and left sides (p>0.05). Compared with the normally shaped condyle side, the BMC side showed no statistically significant differences in the distribution of pain and noise, parasagittal condylar position, or condylar osseous changes, with the exception of osteophytes. In the symptomatic group, osteophytes were found more frequently on the normally shaped condyle side than the BMC side (p<0.05). Conclusion: BMCs tended to be identified as an incidental finding. The presence of BMC would not lead to any TMJ symptoms or cause osseous changes.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.90-98
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• 1998

A Dual Mass Flywheel(D.M.F.) system is an evolution to the reduction of torsional vibration and impact noise occurring in powertrain when a vehicle is either moving or idling. The D.M.F. system has two flywh-eels, which is different from the conventional clutch system. One section belongs to the mass moment of in-ertia of the engine-side. The other section increases the mass moment of inertia of the transmission-side. These two masses are connected via a spring/damping system. This reduces the speed at which the dreaded resonance occurs to below idle speed. Since 1984m D.M.F. system has been developed. However, the processes of development of D.M.F. system don't have any difference from the trial and error method of conventional clutch system. This paper present the method for systematical design of D.M.F. system with dimensionless design varia-bles of D.M.F. system, mass ratio between two flywheels, natural frequency rate of two flywheels, and visc-osity coefficient. And expermental results are used to prove these theoretical results.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5741-5746
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• 2012

Aim: Although preoperative chemoradiatherapy (CRT) has proven its benefits in terms of decreased toxicity, there is still a considerable amount of cases that do not receive postoperative CRT. Oncologists at different geographic locations still need to know the long-term effects of this treatment in order to manage patients successfully. The current paper reports on long-term quality of life (QOL) and late side effects after adjuvant CRT in rectal cancer patients from 5 centers in Anatolia. Methods: Rectal cancer patients treated with postoperative CRT with minimum 1-year follow-up and were in complete remission, were evaluated according to RTOG and LENT-SOMA scales. They were also asked to complete Turkish version of EORTC QLQ-C30 questionnaire and the CR-38 module. Each center participated with the required clinical data. Results: Two hundred and thirty patients with median age of 55 years participated and completed the study. Median follow-up time was 5 years. All patients received RT concomitant with chemotherapy. Common parameters that both increased functional health scales and yielded better symptom scores were long term interval after treatment and sphincter-saving surgery. In addition, surgery type and follow-up time were determined to be predictors of QOL scores and late toxicity grade. Conclusion: Postoperative CRT was found to have a great impact on the long term QOL and side effects in rectal cancer survivors. The factors that adversely affect these are abdominoperineal resection and shorter interval. The findings may encourage life-long follow-up and cooperation with patients, which should be mentioned during the initial counseling.