• Analytical Science and Technology
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• v.24 no.4
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• pp.290-297
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• 2011

In present, evaluation method for car cabin air quality has been developed in ISO, China, Japan. Also The management standard for new produced car has been applied since 1, July, 2010. To manage car cabin air quality, It is important to evaluate VOC emitted from interior material. In this study, complete component of door trim armrest was evaluated in accordance with ISO 12219-5, cut component was evaluated in accordance with ISO 12219-3. The vapour gas was collected with stainless tube packed with Tenax TA and analyzed with TD-GC/MS. It was confirmed that emission rate of each compounds was difficult in each evaluation method. As a result, to evaluating each components composing door trim armrest, main sources of emitting VOCs in door trim armrest were PP substrate and adhesive.

• Journal of Environmental Science International
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• v.9 no.1
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• pp.1-11
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• 2000

A study on the variational characteristics of water quality and phytoplankton biomass by principal component analysis(PCA) was carried out in Kogum-sudo from February to October in 1993. We analyzed PCA on biological factors such as chlorophyll a and phytoplankton cell numbers for centric and pennate diatoms, phytoflagellates, and total phytoplankton as well as physico-chemical factors as water temperature, salinity, transparency, dissolved oxygen(DO), saturation of DO, apparent oxygen utilization (AOU), chemical oxygen demand(COD), nutrient (ammonia, nitrite, nitrate, phosphate and silicate), N/P ratio and suspended solid(SS). The source of nutrients supply depended on the mineralization of organic matters and inputs of seawater from outside rather than runoff of freshwater. The phytoplankton biomass was changed within short interval period by nutrients change. And it was controlled by the combination of several environmental factors, especially of light intensity, ammonia and phosphate. The marine environmental characteristics were determined by the mineralization of organic matters in winter, by runoff of freshwater including high nutrients concentration in spring, by ammonia uptake and high phytoplankton productivity in summer, and phosphate supplied input seawater from outside of Kogeum-sudo in autumn. And Kogum-sudo was separated with 2 regions by score distributions of PCA. That is to say, one region was middle parts of straits which was characterized by the mixing seawater and the accumulated organic matters, other one region was Pungnam Bay and the water around Kogum Island which was done by high phytoplankyon biomass and productivity year-round.

• Journal of the Korean Chemical Society
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• v.13 no.4
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• pp.401-407
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• 1969

The results of water analysis for 10 stations in the main Naktong and 11 stations in the tributaries from March to December 1968 are as follows: The water quality of the Naktong River Basin is generally the frist class of water, especially the tributaries, Hwang river, Nam river, Milyang river, Naesongchun, Hoechun, Wichun and Panbyunchun were dissolved in less than 100 mg/l as the amount of the total ion of the main component. In comparison with river discharge, the amount of the total ion of the main component is decreased in June and July, because of the river discharge is increased in those periods. According to the measurement of the conductivity and the hardness, the better water quality is distinguished by the following order: lower part of river (Namji), middle part of river (Waegwan), upper part of river (Yean). The conductivity of Kumho river, Tongchon is higher than the middle part of the main river and Nam river, Chongam is smaller than lower part of the main rivller. The variation of the amount of the total ion of main component in the basin is mainly effected by $HCO_3^-, SO_4^{-2}, Cl^-, Ca^{+2}$. The relationship between $[K^+]\;and\;[C^l-]\;and\;[Na^+]\;and\;[Cl^-]\;are\;[K^+]=0.04\;[Cl^-]+1.7\;mg/l,\;[Na^+]=0.06\;[Cl^-]$ mg/l .The main river was much contaminated by Kumho river and C.O.D. at Gang-chung, Kumho river in June was recorder over the standard about 7 times.

• Journal of Aerospace System Engineering
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• v.13 no.5
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• pp.79-86
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• 2019

An anti-collision light of a rotary-wing aircraft is used for the purpose of preventing collision during the operation of an aircraft and is a key component to ensure flight safety. The anti-collision lights of the Korean Utility Helicopter (KUH) consist of upper and lower lights, and the power supply of anti-collision lights mounted on the aircraft. The anti-collision light is designed as a dual structure capable of brightness control and selective lighting. During the operation after delivery of the aircraft, abnormal lighting of anti-collision light occurred. In this paper, a comprehensive review of the aircraft system and component level was conducted to solve these phenomena at first. Then, the causes of anti-collision light anomalies were analyzed and the design changes are presented. The validity of design changes has been verified through the component and aircraft system ground/flight test.

• Food Science of Animal Resources
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• v.42 no.4
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• pp.580-592
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• 2022

The aim of the present study was to evaluate the effectiveness of Lycium barbarum polysaccharide (LBP) on lipid oxidation and protein degradation in Tan sheep meatballs during the frozen period. The meatballs were treated with LBP at 0.01%, 0.02%, and 0.03% and stored at -18±1℃ for 0, 3, 6, 9, and 12 weeks. The effects of LBP treatment were investigated using the contents of total volatile basic nitrogen (TVB-N), texture profile (TP), thiobarbituric acid reactive substances (TBARS), colour, and pH values, compared with 0.02% butylated hydroxytoluene treatment and the blank control. The results showed that LBP treatment significantly decreased TBARS content compared with the control, which confirmed LBP to be a highly effective component in preventing lipid oxidation of Tan sheep meatballs during frozen storage, and protein degradation in Tan sheep meatballs had a significant inhibition effect because of TVB-N value reduction. In addition, the colour, TP and pH values of meatballs treated with LBP were improved dramatically. To further determine the quality changes of the blank control and all treated groups during storage, the comprehensive score evaluation equation based on principal component analysis was obtained: Y=0.51632Y₁+0.29589Y₂ (cumulative contribution rate=81.221%), and the 0.02% LBP-treated group had a higher comprehensive score than the other groups, and the quality of LBP-treated meatballs was better as well. In summary, LBP may reduce or inhibit lipid oxidation and protein degradation, and enhance overall quality and shelf-life in prepared meat products.

• The Journal of the Acoustical Society of Korea
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• v.29 no.4
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• pp.270-277
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• 2010

In this paper, we proposed an algorithm that improves tone quality of noisy audio signals by using ICA(Independent Component Analysis) algorithm and perceptual filters. Many algorithms have been proposed to eliminate the noise from the audio signals, such as spectral subtraction method, perceptual filter, etc. The perceptual filter uses a noise that is acquired from silent ranges in the input signal. In this case, the improvement rate of tone quality decreases if the noise energy is changed by the environmental variation in a signal frame. But the proposed method estimates a noise that is changed at each frame using ICA algorithm. The estimated noise is applied to perceptual filter. To show the performance of the proposed algorithm, several tests are performed to various input signals. With the proposed algorithm, we could confirm the enhancement of tone quality in terms of segmental SNR (SSNR), noise-to-mask ratio (NMR) and Degradation Category Rating (DCR) test.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.3
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• pp.137-144
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• 2015

The purpose of this study is to develop an warning system to detect real-time water quality abnormality using a multivariate statistical approach. In this study, we applied principal component analysis among multivariate data analyses which was used for the correlation between water quality parameters considering the real-time algorithm to determine abnormality in water quality. We applied our approach to real field data and showed the utilization of algorithm for the real-time monitoring to find water quality abnormality. In addition, our approach with Korea Meterological Adminstration database identified heavy rain data due to climate change is one of the most important factors to explain water quality abnormality.

• Journal of Sasang Constitutional Medicine
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• v.29 no.1
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• pp.21-28
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• 2017

Objectives The purpose of this study was to investigate of Quality of life and Mibyeong index of abnormal symptoms by Sasang constitution. Methods A total of 1,100 people were recruited into this study and were collected by Gallup Korea. Sasang constitutions were diagnosed based on KS-15 (Korean sasang constitutional diagnostic questionnaire) Questionnaire which comprised body type, personality and symptom. In addition, SF-12 (Shot form-12) questionnaire was used to evaluate the quality of life status. Mibyeong status was categorized through Mibyeong tool. Data were analyzed through one-way ANOVA to investigate the difference between quality of life and Mibyeong index on Sasang constitution. Results The PCS (physical component scale) which represents the physical health index and MCS (mental component scale) which represents mental health index showed significant differences among Sasang constitution (p<.001). In addition, The Mibyeong Index (p<.001) which represents abnormal symptom type showed significant difference for Sasang constitution. As for the Mibyeong, only pain (p=0.047) and fatigue (p=0.021) had changes for the Sasang constitution. Conclusions Quality of life and Mibyeong index vary significantly according to Sasang constitution. This results suggest the analysis of Mibyeong index by Sasang constitution could provide the setting of direction to promote public health depending on Sasang constitution.

• Journal of Society of Preventive Korean Medicine
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• v.21 no.2
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• pp.35-44
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• 2017

Objectives : The purpose of this study was to investigate the association between quality of life and Mibyeong index of abnormal symptoms by the Mibyeong state. Methods : A total of 1,100 people were recruited into this study and were collected by specialized research company. The data were collected by personal information using MBI(Mibyeong Index) and SF-12 (Short form-12) and were analyzed with SPSS (version 21.0) computer program, and included Pearson's chi-square test, ANOVA, Pearson's correlation coefficient, and multiple regression analysis. Results : The Mibyeong Index which represents abnormal symptom type showed significant difference for Mibyeong state (p<.001). In Total subject, fatigue, pain, low sleep quality and indigestion were found to be significant predictors of PCS(Physical Component Summary). In Healthy group, pain was found to be significant predictor of PCS. In MI 1 group, fatigue, pain, indigestion and anxiety were found to be significant predictors of PCS. In MI 2 group, fatigue, pain and low sleep quality were found to be significant predictors of PCS. In Total subject, fatigue, depression, anger and anxiety were found to be significant predictors of MCS (Mental Component Summary). In Healthy group, indigestion and anxiety were found to be significant predictors of MCS. In MI 1 group, depression and anger were found to be significant predictors of MCS. In MI 2 group, fatigue and depression were found to be significant predictors of MCS. Conclusions : The relationship between Quality of life and MBI changes according to Mibyeong state. We expect that this result could be contribute to health management of people in Mibyeong state.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.3
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• pp.7-17
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• 2017

Loan consultants assist clients with loan application processing and loan decisions. Their duties may include contacting people to ask if they want a loan, meeting with loan applicants and explaining different loan options. We studied the efficiency of service quality of loan consultants contracted to a bank in Korea. They do not work as a team, but do work independently. Since he/she is not an employee of the bank, the consultant is paid solely in proportion to how much he/she sell loans. In this study, a consultant is considered as a decision making unit (DMU) in the DEA (Data Envelopment Analysis) model. We use a principal component analysis-data envelopment analysis (PCA-DEA) model integrated with Shannon's Entropy to evaluate quality efficiency of the consultants. We adopt a three-stage process to calculate the efficiency of service quality of the consultants. In the first stage, we use PCA to obtain 6 synthetic indicators, including 4 input indicators and 2 output indicators, from survey results in which questionnaire items are constructed on the basis of SERVQUAL model. In the second stage, 3 DEA models allowing negative values are used to calculate the relative efficiency of each DMU. In the third stage, the weight of each result is calculated on the basis of Shannon's Entropy theory, and then we generate a comprehensive efficiency score using it. An example illustrates the proposed process of evaluating the relative quality efficiency of the loan consultants and how to use the efficiency to improve the service quality of the consultants.