• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.217-222
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• 2004

In recent year, as the current and future emission regulations go stringent, the research of exhaust manifold and CCC has become the subject of increasing interest and attention. This study is concerned with the systematic approach to improve catalyst flow uniformity and light-off behavior through the basic understanding of exhaust flow characteristics. Computational approach to the unsteady compressible flow for exhaust manifold of 4-1 type and 4-2-1 type and CCC system of a 4-cylinder DOHC gasoline engine was performed to investigate the flow distribution of exhaust gases. In this study, through calculation, the effects of geometric configuration of exhaust manifold on flow structure and its maldistribution in monolith were mainly investigated to understand the exhaust flow patterns in terms of flow uniformity. Based on the design guidance resulting from this fundamental study, the flow uniformity of 4-2-1 type exhaust manifold demonstrated the more improved exhaust characteristics than that of the 4-1 type one.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.138-145
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• 2013

Airworthiness certification is a government certification for the military aircraft to safely attain, sustain and terminate flight and It is a mandatory process of qualifying the flight safety within the operational boundaries of a military aircraft. To save the manhour, time and cost for applying all the airworthiness certification criteria to the aircraft equipped with flight control switching mechanism development program, an identification of the risk and systematic assessment of risk is analysed. Airworthiness redesign actions so called software switching mechanism for the modified aircraft in the flight technology and electric system area are suggested to reduce the risk hazard index.

• Environmental Engineering Research
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• v.23 no.1
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• pp.107-113
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• 2018

Air quality and pollution have recently become a major concern; vehicle emissions significantly pollute the air, especially in large and crowded cities. There are various factors that affect vehicle emissions; this research aims to find the most influential factors affecting $CO_2$ and $NO_x$ emissions using Adaptive Neural Fuzzy Inference System (ANFIS) as well as a systematic approach. The modified ANFIS (MANFIS) was developed to enhance modelling and Root Mean Square Error was used to evaluate the model performance. The results show that percentages of $CO_2$ from trucks represent the best input combination to model. While for $NO_x$ modelling, the best pair combination is the vehicle delay and percentage of heavy trucks. However, the final MANFIS structure involves two inputs, three membership functions and nine rules. For $CO_2$ modelling the triangular membership function is the best, while for $NO_x$ the membership function is two-sided Gaussian.

• Journal of Korean Academy of Nursing
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• v.29 no.5
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• pp.1113-1122
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• 1999

The author investigated pain experiences of 90 cancer patients and the adequacy of pain treatment they have received during their stay at a large medical center in T city between October 1994 and August 1995. Pain was assessed by the Shortened BPQ and results are summarized as follows: As for ratings of “worst pain” during the 24 hour period, 70% of the patients reported they had “severe” pain. As for ratings on “pain now,” 43% of the cancer patients reported “moderate to severe” pain. Over 46% of the patients reported a pain relief score of 0(not at all) or 1(somewhat) even after receiving pain medication. Adequacy of analgesic treatment was evaluated by comparing the patient's reported level of pain and the analgesic use, namely, the pain management index(PMI). The PMI indicated that 58% of the patients were undertreated for the pain control. In review of nurse's notes. systematic pain assessment was scarcely recorded, although pain documentation appeared in 70% of the notes; and the contents were mostly simple description. In conclusion, the results of patient's pain ratings, the PMI and poor pain documentation in the nurse's notes implied poor pain assessment and management.

• Journal of the Korean Data and Information Science Society
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• v.27 no.6
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• pp.1661-1671
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• 2016

Risk analysis is a systematic study of uncertainties and risks we encounter in business, engineering, public policy, and many other areas. Value at Risk (VaR) is one of the most widely used risk measurements in risk management. In this paper, the Korean Composite Stock Price Index data has been utilized to model the VaR employing the classical ARMA (1,1)-GARCH (1,1) models with normal, t, generalized hyperbolic, and generalized pareto distributed errors. The aim of this paper is to compare the performance of each model in estimating the VaR. The performance of models were compared in terms of the number of VaR violations and Kupiec exceedance test. The GARCH-GPD likelihood ratio unconditional test statistic has been found to have the smallest value among the models.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.62-66
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• 2000

This study investigated the effects of certain specific wavelengths of lighting on the autonomic nervous system (ANS) using the heart rate variability (HRV) as an index. Six subjects with normal color vision participated n this study between 15:00 and 17:00 hr to neutralize any visual differences arising from circadian rhythm. The environmental conditions of the laboratory were maintained in complete darkness and the temperature was equilibrated at 24$\Box$ with a relative humidity of 60%. Subjects were only subjected to light stimulation when the pupil of dyes attained a minimum size of 2 mm by projecting illumination equalized with the same spectral radiance of 500-700 nm with 50-nm internal radiance. HRV was calculated from electrocardiogram (ECG) with systematic respiratory control at 0.35 Hz. The results suggest that illumination with certain wavelengths may induce ANS activation.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.226-227
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• 2006

Wind power is one of the fastest growing distributed generation types. As part of a worldwide trend, the concerns of large wind generation have been risen rather than small wind generation since it influences the whole power system Including the transient stability. The objective of this paper is to understand the effect of a large-scale wind generation on power system transient stability and to develop a systematic procedure to assess the effect according to the location and capacity of a wind farm. In the proposed procedure, an index is presented to evaluate the appropriateness of the location and capacity of a wind farm for transient stability contingencies.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.4 s.148
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• pp.521-528
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• 2006

In this study, we developed a new systematic approach to assess the influence of geometric parameter change on the horizontal and vertical stability indices. To do this, three phases of sensitivity analyses were carried out. First, typical geometric parameters were defined and their effects on hydrodynamic coefficients were assessed by the Sensitivity Analysis (SA) of the indirect method. Second, the effects of hydrodynamic coefficients on the stability indices were calculated. Finally, the sensitivities of geometric parameters on the stability indices were obtained by merging the outputs of two phases using chain rule. The developed approach cau contribute to a submarine designer to determine geometric parameters satisfying pre-requirements about stability systematically.

• Korean Journal of Optics and Photonics
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• v.11 no.4
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• pp.255-260
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• 2000

We report that the crack-free organic-inorganic hybrid silica thin films were fabricated by sol-gel process using organometallic compounds as a precursor and that we have established very reproducible fabrication condition with systematic investigation of thickness and refractive index variations for various control parameters, such as, coating type, coating speed, chemical composition, prebake and postbake temperature. Additionally, we measured and compared the change of optical property with the UV exposure dose for three different kinds of photoinitiators. Furthermore, the fabrication of Ix4 MMI optical power splitter using the sol-gel thin film provides the possibility of various applications to the optical waveguide devices. vices.

• Journal of Korean Academy of Nursing
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• v.34 no.3
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• pp.576-585
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• 2004

Purpose: The purpose of this study was to identify the relationship between eating disorders, physical symptoms, depression and health locus of control. Method: The research design was a descriptive study done by using a constructive self-report questionnaire. A total of 464 elementary school girls were measured. The instrument was a constructive questionnaire that consisted 136 items. The subjects were divided into 4 groups according to the Body Mass Index (BMI). Data analysis was done by SPSS/WIN Programs using frequency, percentage, mean, SD, ANOVA, Pearson correlation coefficient, and stepwise multiple regression. Result: The score of eating disorders differed significantly by BMI : the score was highest in the group of obese students(F=4.208, P=.015). Stepwise multiple regression analysis revealed that the most powerful predictor of eating disorders was BMI. Conclusion: These results indicate that Korean elementary school girls need more education and counseling on diet. Also, we should take systematic efforts to reestablish the social standard of beauty to promote normal growth development.