• Journal of Korean Society on Water Environment
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• v.35 no.3
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• pp.257-270
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• 2019

Followingthe Four Rivers Project, cyanobacterial blooms have been frequently observed in the upstream of the installed weirs. The aim of this study was to characterize the major environmental factors that are associated with the cyanobacteria dominance in Baekje Weir (Geum River) and Juksan Weir (Youngsan River) based on intensive experiments and systematic data mining methods. The factors related to the cyanobacteria dominance include7-days cumulative rainfall (APRCP7), 7-days averaged flow (Q7day), water temperature (Temp), stratification strength (${\Delta}T$), electronic conductivity (EC), DO, pH, $NO_3-N$, $NH_3-N$, TN, TP, $PO_4-P$, Chl-a, Fe, BOD, COD, TOC, and $SiO_2$. The most highly correlatedfactors to the dominant cyanobacteria were found to be EC, Temp, Q7day, $PO_4-P$ in theBaekje Weir. On the other hand, those dominant in the Juksan Weir were ${\Delta}T$, TOC, Temp, EC and TN. The EC showed a strong correlation with cyanobacteria dominance in both weirs because a high EC represents a persisted low flow condition. The cyanobacteria dominance was as high as 56 % when the EC was equal or greater than $418{\mu}S/cm$ in Baekje Weir. It was as high as 63% when the ${\Delta}T{\geq}2.1^{\circ}C$ in the Juksan Weir. However, nutrients showed a minor correlation with cyanobacteria dominance in both weirs. The results suggest that the cyanobacteria dominate in astate where the water flow rate is low, water temperature is high and thermal stratification is strengthened. Therefore, the improvement of flow regimes is the most important to prevent persistent thermal stratification and formation of cyanobacteria bloom in theBaekje and JuksanWeirs.

• Atmosphere
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• v.31 no.1
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• pp.29-43
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• 2021

In this study, two-step statistical approach including Principal Component Analysis (PCA) and Multiple Linear Regression (MLR) was employed, and main meteorological factors explaining the high-PM2.5 episodes were identified in two regions: Seoul and Busan. We first performed PCA to isolate the Principal Component (PC) that is linear combination of the meteorological variables observed at two levels: surface and 850 hPa level. The employed variables at surface are: temperature (T2m), wind speed, sea level pressure, south-north and west-east wind component and those at 850 hPa upper level variables are: south-north (v850) and west-east (u850) wind component and vertical stability. Secondly we carried out MLR analysis and verified the relationships between PM2.5 daily mean concentration and meteorological PCs. Our two-step statistical approach revealed that in Seoul, dominant factors for influencing the high PM2.5 days are mainly composed of upper wind characteristics in winter including positive u850 and negative v850, indicating that continental (or Siberian) anticyclone had a strong influence. In Busan, however, the dominant factors in explanaining in high PM2.5 concentrations were associated with high T2m and negative u850 in summer. This is suggesting that marine anticyclone had a considerable effect on Busan's high PM2.5 with high temperature which is relevant to the vigorous photochemical secondary generation. Our results of both differences and similarities between two regions derived from only statistical approaches imply the high-PM2.5 episodes in Korea show their own unique characteristics and seasonality which are mostly explainable by two layer (surface and upper) mesoscale meteorological variables.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.416-424
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• 2014

Objectives: The objective of this study is to analyze the predominant microorganisms in the industry treating MWFs(Metal working fluids). Methods: The bacteria and fungi were collected by agar plate impaction and bulk MWFs in storage tank at 54 sites in 9 shops in South Korea. The dominant bacteria and fungi isolated from agar media were identified by fatty acid analysis and morphological analysis, respectively. Results: Totally 111 dominant bacteria were identified in the process, outdoor, and bulk MWFs. The predominant bacterial genus was Micrococcus and Bacillus in the process and outdoor, Pseudomonas in bulk MWF. Among the identified 119 strains of fungi, Cladosporium and Penicillium genus were dominated. The ratios of bacteria designated biosafety level 2 and 1 were 30% and 21%, respectively. Conclusions: This study has investigated the dominant microorganisms in soluble MWF using industry. And it was useful that the qualitative evaluation method along with quantitative analysis for better understanding of the biological factors in the work environment.

• The Korean Journal of Ecology
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• v.8 no.3
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• pp.171-176
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• 1985

The structure of natural vegetation and soil condition in bog area of Woopo, Changnyeung, South Korea were observed. The vegetations in the investigated area could be classified into two groups; a typical bog vegetation with dominant species of Eleocharis mamillats, Acorus calamus and Persicaria hostatosagittata and the transitional vegetation of three neighboring areas. Interspecific correlation in the investigated area was very close. In the typical bog vegetatiion regions (region II, III, V, VI, VII, VIII and X) soil pH, field moisture capacity, available P content and exchangeable K were moderate. But, In the transitiional area I, with the highest humus content, field moisture capacity and exchangeable K Salix gracilistyla was dominant. In the region IV with the lowest humus and a ailable P content and with high soil pH Geophyta was a major component species. Also Acorus region IX with the lowest content of exchangeable K Therophyta was dominant and plant species was diverse due to weak water influence. The vegetation structure of the region IX was most different from that of the whole vegetation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.7
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• pp.253-260
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• 2001

A Study of interior noise reduction in the magelv train is presented. Tarin speed of interest is low such that aero-dynamic noise is negligible and power supply system is a dominant noise source. Based on the measurements of interior noise and acceleration levels during running and zero speed conditions, dominant noise sources are identified. After spectra characteristics of noise sources are investigated several noise reducing methods are studied such as STL increasement of floor panels. sealing. and absorption treatment It is found that the most important noise sources are VVVF inverter and SLM in running condition, whereas air conditioner and DC/DC converter are dominant in zero speed. Sine the major noise sources are under the floor complete sealing and high STL of the floor panel are shown to be the most crucial factors in noise reduction After sound absorbing material, which is polyurethan foam of 50 mm thickness, is thickness, is attached to the downward side of the floor in addition to sealing treatment, the interior noise is reduced by 3~4 dB.

• Journal of the Korean Society of Costume
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• v.38
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• pp.323-336
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• 1998

The purpose of this study was to classify the contents of self-image of college men and to investigate how clothing behavior was influenced by self-image, age, major, and the expenses of clothing. Samples were 342 male students of univer-sity in Seoul. Results of this study were following : 1. Four factors of self-image derived by factor analysis : F. 1‘mature-unmatured’;F. 2‘characteristic-ordinary’; F. 3‘conservative-open’; F. 4‘dominant-submissive’.2. 5 variables of clothing behavior were influenced by real self-image. Fashion was influenced by characteristic, open, dominant image, and the expenses of clothing. The ex-planatory power of the 4 variables was 29.3%. Aesthetics was influenced by characteristic, submissive, conservative image, the expenses of clothing, and age(R2=28.7%). Modesty was influenced by conservative and ordinary im-age(R2=6.5%). Coformity was influenced by ordinary image and the expenses of clothing (R2=5.7%). Comfort was influenced by dominant image and age(R2=5.3%). 3. 5 variables of clothing behavior were influenced by ideal self-image. Fashion was influenced by unmatured, characteristic, sub-missive image, and the expenses of clothing (R2=28.9%). Aesthetics was influenced by characteristic image, the expenses of clothing, and age(R2=23.5%). Modesty was influenced by conservative, mature, and ordinary image (R2=8.3%). Coformity was influenced by ordinary image(R2=1.9%). Comfort was influenced by mature image and age(R2=5.6%). The findings indicated that self-image had a significant effect on fashion and aesthetics, and characteristic image and conservative image were important variables that affected clothing behavior of college men.

• Wind and Structures
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• v.24 no.1
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• pp.79-93
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• 2017

Wind-induced fluctuating internal pressures in a building with a dominant opening can be described by a second-order non-linear differential equation. However, the accuracy and efficiency of the governing equation in predicting internal pressure fluctuations depend upon two ill-defined parameters: inertial coefficient $C_I$ and loss coefficient $C_L$, since $C_I$ determines the un-damped oscillation frequency of an air slug at the opening, while $C_L$ controls the decay ratio of the fluctuating internal pressure. This study particularly focused on the value of loss coefficient and its influence factors including: opening configuration and location, internal volumes, as well as wind speed and approaching flow turbulence. A simplified formula was presented to predict loss coefficient, therefore an approximate relationship between the standard deviation of internal and external pressures can be estimated using Vickery's approach. The study shows that the loss coefficient governs the peak response of the internal pressure spectrum which, in turn, will directly influence the standard deviation of the fluctuating internal pressure. The approaching flow characteristic and opening location have a remarkable effect on the parameter $C_L$.

• Wind and Structures
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• v.18 no.1
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• pp.57-67
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• 2014

For a building with a dominant windward wall opening, the wind-induced internal pressure response can be described by a second-order non-linear differential equation. However, there are two ill-defined parameters in the governing equation: the inertial coefficient $C_I$ and the loss coefficient $C_L$. Lack of knowledge of these two parameters restricts the practical use of the governing equation. This study was primarily focused on finding an accurate reference value for $C_I$, and the paper presents a systematic investigation of the factors influencing the inertial coefficient for a wind-tunnel model building including: opening configuration and location, wind speed and direction, approaching flow turbulence, the model material, and the installation method. A numerical model was used to simulate the volume deformation under internal pressure, and to predict the bulk modulus of an experimental model. In considering the structural flexibility, an alternative approach was proposed to ensure accurate internal volume distortions, so that similarity of internal pressure responses between model-scale and full-scale building was maintained. The research showed 0.8 to be a reasonable standard value for the inertial coefficient.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.3
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• pp.361-372
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• 2000

The purposes of this study were to investigate consumer's antecedent mood, cognitive factors, and experienced affection, to find out the relationships among antecedent mood, cognitive factors, experienced affection, and consumer's characteristics, and to examine the discriminant variables of apparel buying behaviors. We developed an questionaire based on the previous studies and pretests. We collected data from 443 housewives living in Pusan and analyzed by Factor analysis, t-test, and Discriminant analysis. The results showed as following: 1. Antecedent mood consists of four factors and cognitive factors in store were composed of four factors. Experienced affection in store includes Pleasure, Dominant and Stimulating feeling. 2. We discovered that consumer characteristics related to the antecedent mood, the experienced affection and cognitive factors in store. 3. Purchasers didn't relate to the consumer characteristics, and related to the antecedent mood, the cognitive factors, the experienced affection in store. Experienced affection and antecedent moods appeared to be important factors in determining apparel buying behavior of consumers. Especially, Pleasure and Dominance of the experienced affection and Depression, Excitation/expectation. Worry and Self-encouraging of the antecedent moods were more important variables in determining apparel buying behavior than any other variables.

• Journal of Korean Medicine for Obesity Research
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• v.18 no.2
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• pp.115-127
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• 2018

Objectives: People often fail to reduce or maintain their weight despite trying to lose weight. The purpose of this study was to review previously published study results of the predictive factors associated with weight loss in obesity treatment. Methods: Authors searched for the articles related to weight loss, published from 2007 to 2017 found on PubMed, Scopus, Research Information Sharing Service (RISS), and Koreanstudies Information Service System (KISS). A total of 43 articles were finally selected. From the study results, unchangeable and changeable predictors were extracted, and these predictors were examined according to detailed categories. Results: Predictors of weight loss in obesity treatment included genetic and physiological factors, demographic factors, history of treatment on obesity related factors, behavioral factors, psychological factors and treatment process related factors. The main factors of weight loss were unchangeable predictors such as high initial degree of obesity and younger age, and changeable predictors such as dietary restraint, regular exercise, self-efficacy, initial weight loss and attendance. Especially dietary restraint, regular exercise, successful initial weight loss and high attendance were considered to be dominant factors for weight loss treatments. Conclusions: Our review results suggest that unchangeable and changeable predictors of weight loss should be carefully examined during treatments of obesity.