• 수도
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• v.24 no.2 s.83
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• pp.49-59
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• 1997

• Journal of the Korean housing association
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• v.17 no.2
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• pp.77-85
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• 2006

This study aims to propose the comprehensive evaluation of performance multi-family housing. Most of the existing studies for the reproduction have evaluated by the safety of structure. Therefore those pass over the functional factors which is important for the evaluation of residential qualities. This study represents that the reproduction renovation should not be secured the safety of structure but established the quality of lift. And questionnaire asking expert's opinion also supplemented. As a result, the item for examination and the weight for evaluation are suggested in functional deterioration. The results of this study are summarized as follows: 1. Existent redevelopment criteria are not appropriate to decide the environmental comfort, the vital function of housing and the residential management finance. 2. The future criteria have to evaluate the existing environmental comfort, be reconstructed to put first general deterioration. 3. Evaluation elements was extracted throughout the document research, evaluation elements analysis system was separated in residential area, suburb of dwellings, community, and housing complexity environmental assesment, 4. Each category of influence ratio was extracted to assess total deterioration throughout the expert question survey. 5. Each category analysed (1) $0{\sim}30%$: function is good (unnecessary to improve) (2) $31{\sim}40%$: average (necessary of partial improvement) (3) $41{\sim}59%$: bad (necessary of total improvement) (4) $60{\sim}100%$: the worst (unable to improve throughout the repair)

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.27-30
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• 2011

Analysis data of basics which are used for LCC(Life Cycle Cost) analysis of buildings and maintenance plan, are demanded to secure according as replacement cycle of repairs of apartment houses has come. However, investigation techniques and systems for investigating condition of deterioration of apartment houses, have not been made yet in Korea. For this reason, this study was wanted to make investigation techniques and systems, so the process for maintenance of apartment houses was researched and the required quality and deterioration factors of interior/exterior materials were investigated. As a result Check-List for investigating condition of deterioration, was made. if this is used during a nonscheduled, a routine, a regular and a urgency check, the methodical investigation will be achieved. Furthermore, if this is used for maintenance of apartment houses, it will be helped to select the repair cycle and the long-term repair plan.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.711-716
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• 2012

To assess the insulation deterioration of stator windings, diagnostic and AC breakdown tests were performed on the eleven high voltage (HV) motors rated at 6kV. After completing the diagnostic tests, the AC overvoltage test was performed by gradually increasing the voltage applied to the stator windings until electrical insulation failure occurred, to obtain the breakdown voltage. Stator winding of motors 1, 3, and 8 failed at above rated voltage at 14 kV, 13.8kV, and 16.4kV, respectively. The breakdown voltage of three motors was higher than expected for good quality windings in 6kV motors. Based on deterioration evaluation criteria, the stator winding insulation of eleven HV motors are confirmed to be in good condition. The turning point of the current, $P_{i2}$, in the AC current vs. voltage characteristics occurred between 5kV and 6kV, and the breakdown voltage was low between 13.8kV and 16.4kV. There was a strong correlation between the breakdown voltage and various electrical characteristics in diagnostic tests including Pi2.

• Journal of Korea Water Resources Association
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• v.51 no.11
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• pp.959-969
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• 2018

The aging water pipes induce various problems, such as water supply suspension due to breakage, insufficient water pressure, deterioration of water quality, damage by sink holes, and economic losses due to water leaks. However, it is impractical and almost impossible to repair and/or replace all deteriorated water pipes simultaneously. Hence, it is required to quantitatively evaluate the deterioration rate of individual pipes indirect way to determine the rehabilitation order of priority. In this study, ANN(Artificial Neural Network)-Clustering method is suggested as a new approach to assess and assort the water pipes. The proposed method has been applied to a water supply network of YG-county in Jeollanam-do. To assess the applicability of the model, the evaluation results were compared with the results of the Numerical Weighting Method (NWM), which is being currently utilized in practice. The assessment results are depicted in a water pipe map to intuitively grasp the degree of deterioration of the entire pipelines. The application results revealed that the proposed ANN-Clustering models can successfully assess the water pipe deterioration along with the conventional approach of NWM.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.772-782
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• 2015

This study was performed to explore the deterioration of physicochemical quality of beef hind limb during frozen storage at −20℃, affected by repeated freeze-thaw cycles. The effects of three successive freeze-thaw cycles on beef hind limb were investigated comparing with unfrozen beef muscle for 80 d by keeping at −20±1℃. The freeze-thaw cycles were subjected to three thawing methods and carried out to select the best one on the basis of deterioration of physicochemical properties of beef. As the number of repeated freeze-thaw cycles increased, drip loss decreased and water holding capacity (WHC) increased (p<0.05) till two cycles and then decreased. Cooking loss increased in cycle one and three but decreased in cycle two. Moreover, drip loss, WHC and cooking loss affected (p<0.05) by thawing methods within the cycles. However, pH value decreased (p<0.05), but peroxide value (p<0.05), free fatty acids value (p<0.05) and TBARS value increased (p<0.05) significantly as the number of repeated freeze-thaw cycles increased. Moreover, significant (p<0.05) interactive effects were found among the thawing methods and repeated cycles. As a result, freeze-thaw cycles affected the physicochemical quality of beef muscle, causing the degradation of its quality.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1164-1167
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• 2009

Motion-image-quality of LCD-TVs is discussed by dynamic spatial frequency response. Smaller temporal aperture or higher frame rate can improve dynamic response, but an increase of motion velocity easily cancels the improvement. A guideline for deciding the desirable temporal aperture and frame rate of LCD-TVs is described, under the condition that camera and display have the same parameters. Two candidates of the desirable parameter sets will be (240 or 300 Hz, 50 to 100% aperture) and (120Hz, 25 to 50% aperture), from the viewpoint of "limit of acceptance" on motion-imagequality-deterioration for critical picture materials.

• Food Science and Preservation
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• v.4 no.2
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• pp.189-196
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• 1997

Blanching conditions for immatured soybeans were optimized by analyzing the effects of various time/temperature blanch treatment on the activities of peroxidase and lipoxygenase, the stability of vitamin C and color, and moisture content in immatured soybeans for the purpose of minimizing quality deterioration during frozen storage. Blanching at 96$^{\circ}C$ for 70 sec led to maximum inactivation of lipoxygenase in the immatured soybeans, while my blanching conditions tested in this study were not enough to inactivate peroxidase. Blanching at 82$^{\circ}C$ for 60 sec resulted in the highest amount of vitamin C remaining in the immatured soybeans after blanching. Hunter -a/b ratios of immatured soybeans blanched at 82$^{\circ}C$ for 60 sec and hue values (ΔE) of the immatured soybeans blanched at 76$^{\circ}C$ for 60 sec showed the closest values to those of fresh products. The changes in moisture content of immatures soybeans was not so significant after blanching. In conclusion, it was suggested that immatured soybeans be blanched at 96$^{\circ}C$ for 70 sec to minimize lipoxygenase activity and resulting quality deterioration, while blanching at 82$^{\circ}C$ for 60 sec was recommended to stabilize vitamin C and color.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.107-111
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• 2009

Acoustic OFDM is used for audible frequency band acoustic communication which employs loudspeaker as transmitter and microphone as the receiver antenna. Since acoustic OFDM can transmit about 1 kbps using 1600 Hz band. acoustic OFDM signal is inserted into the audio signal like music or speech, However. audio quality deteriorates definitely during the inserting process. This paper introduces a reason for audio quality deterioration and discuss how to reduce this phenomenon.

• Journal of Korean Society for Quality Management
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• v.43 no.4
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• pp.589-606
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• 2015

Purpose: In developing new products, reducing performance variation is important for competitiveness factors such as quality, cost, and delivery. This paper aims at evaluating three performance variations; measurement, performance evaluation, and manufacturing variations, and then improving product and process design, focused on paper helicopter making case study. Methods: For measurement system analysis, gage R&R (repeatability and reproducibility), linearity, stability are evaluated. Since gage R&R are not satisfactory, the measurement system is improved by adopting voice memos application of iPhone and providing standard measurement procedure. To evaluate performance variation, product deterioration and environment factor (wind speed) is considered. Since the existing design is sensitive to these noise factors, a new product design is developed, which is proven to be robust to the noise factors. Finally, manufacturing variations are evaluated with five factors which can cause variation in flight time. To reduce the impact of three significant factors, three improvement methods are applied. Results: Three performance variations are evaluated and robust paper helicopter design is presented. Conclusion: To reduce measurement and process variations, improved measurement method and paper helicopter making procedure are proposed. A new product design is also presented which is robust to deterioration and environmental variation. This paper is expected to benefit students and practitioners who want to have hands-on knowledge on new product quality improvement.