• Plant Journal
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• v.10 no.2
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• pp.38-47
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• 2014

Renewable Portfolio Standards was introduced into the system in Korea in 2012. Interest in the unutilized and renewable energy sources is increasing. and these being actively investigated. An organic rankine cycle has emerged as an alternative in order to take advantage of bio-gas engine heat of sewage treatment plants whose capacity is 1500 kW. The organic rankine cycle power system was simulated by a simulator which is a commercial program of power plant design and performance analysis. The biogas engine is operated by $460^{\circ}C$ and 2.7 kg/s flow rate in the sewage treatment plant. Working fluids(R-601a, R-123, R-245fa) are selected to use in ORC power system in this temperature range. It was the isopentane that is the best performance among three working fluids. It could be obtained net power of 163.1 kW and efficiency of 13.66% from isopentane in the simulation.

• Korean Journal of Community Nutrition
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• v.15 no.4
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• pp.513-524
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• 2010

This study was designed to examine nutrition label use, self-efficacy, snacking and eating behaviors of middle school students, and to investigate if these characteristics were different by nutrition label use. A cross-sectional survey was conducted to 348 middle school students in Kyunggi, Korea. About a third of subjects read nutrition labels when they purchased snacks/packaged foods. Most nutrition label users were interested in reading information on calories, fat and trans-fat. Self-efficacy of eating/selecting snacks or general nutrition behavior was moderate (mean score: 44.4 out of 60), with significantly higher score in nutrition label users compared to nonusers (p < 0.001). Nutrition label users felt more confident in 9 items out of 15 items of self-efficacy, such as "taking fruits instead of cookies/candy for snack" (p < 0.001), "choosing milk instead of soft drink" (p < 0.01), "not having snacks after dinner" and "avoiding processed foods for snacks" (p < 0.05). Subjects had snacks 1.3 times a day, and nutrition label nonusers consumed snacks more frequently than the counterparts (p < 0.01). About 55% of nutrition label users and 64.7% of nonusers mainly purchased snacks for themselves (p < 0.05). Commonly purchased snacks by adolescents were ice cream, cookies/chips, breads and ramen. Major considerations in purchasing snacks were taste (46.9%) and price (34.6%). In selecting snacks, the influence of friends and parents was greater than the other sources. Based on eating frequency of snacks, nutrition label users were more likely to consume healthy snacks, such as fruit juices, vegetables, milk, yogurt, and potato/sweet potato than nonusers (p < 0.05). Eating behaviors measured by 15 items scored 33.6 out of 45. Nutrition label users showed better eating behaviors, such as "eating meals slowly", "eating foods cooked with plant oil", and "eating out less frequently" (p < 0.05). Study results showed that majority of adolescents did not read nutrition labels, selected snacks for themselves and had somewhat unhealthy foods for snacks. This study also showed the differences in self-efficacy, snacking and eating behaviors between nutrition label users and nonusers. In nutrition education, it is necessary to stress the importance and skills for reading nutrition labels. It is also needed to help adolescents to select healthy snacks and have desirable eating behaviors, as well as increasing self-efficacy.

• Korean Journal of Social Welfare
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• v.68 no.3
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• pp.73-103
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• 2016

In this study, it investigates the life of normal adolescents who have parents with intellectual disability and their difficulties which suggested social welfare meanings of this study. In order to conduct wide and in-depth analysis on cases by utilizing the characteristics of qualitative case studies, it describes and analyzes the intellectual disability parents' normal children in detail from the viewpoint of an insider through in-depth interviews, various sources and diverse data collecting methods. As for the subject of this study, both parents should be persons with intellectual disability and their child shall be non-disabled and at least a high school student or older. Through the intentional sampling, five late adolescents who were in high school, all males participated in the study. The data collection process had been conducted from January 2014 to May, which is commonly utilized for qualitative case studies, and comparative analysis between cases were practiced for analysis. For credibility of the research results, it obtained severity at each stage by meeting the standard. The analysis results were largely divided into "growth story of non-disabled adolescents" and "life of non-disabled adolescents". Nine upper categories analyzed the common features in each case. The nine categories were "no one tells me to study", "advance while learning the sense of academic achievement", "hide into my own space", "having to grown up early", "different parents but same love", "relatives raised me", "have a friend who accepts me as I am", "being pressed by poverty", and "standing on a knife edge of being hurt and taking heart". Based on the in-depth research on normal teens that have intellectually disabled parents, theoretically speaking, this study expanded the prospect of study on intellectually disabled to their normal, intellectual teenage children. As for practical significance, understanding their parents' intellectual disability, parenting technique training, case management from the community level is suggested. Rregular real condition research of the families, allowance system for economic support et al. is suggested in policy aspect.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.559-563
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• 2015

Monitor of All-sky X-ray Image (MAXI) is a Japanese X-ray all-sky surveyer mounted on the International Space Station (ISS). It has been scanning the whole sky since 2009 during every 92-minute ISS rotation. X-ray transients are quickly found by the real-time nova-search program. As a result, MAXI has issued 133 Astronomer's Telegrams and 44 Gamma-ray burst Coordinated Networks so far. MAXI has discovered six new black holes (BH) in 4.5 years. Long-term behaviors of the MAXI BHs can be classified into two types by their outbursts; a fast-rise exponential-decay type and a fast-rise flat-top one. The slit camera is suitable for accumulating data over a long time. MAXI issued a 37-month catalog containing 500 sources above a ~0.6 mCrab detection limit at 4-10 keV in the region ${\mid}{b}{\mid}$ > $10^{\circ}$. The SSC instrument utilizing an X-ray CCD has detected diffuse soft X-rays extending over a large solid angle, such as the Cygnus super bubble. MAXI/SSC has also detcted a Ne emission line from the rapid soft X-ray nova MAXI J0158-744. The overall shapes of outbursts in Be X-ray binaries (BeXRB) are precisely observed with MAXI/GSC. BeXRB have two kinds of outbursts, a normal outburst and a giant one. The peak dates of the subsequent giant outbursts of A0535+26 repeated with a different period than the orbital one. The Be stellar disk is considered to either have a precession motion or a distorted shape. The long-term behaviors of low-mass X-ray binaries (LMXB) containing weakly magnetized neutron stars are investigated. Transient LMXBs (Aql X-1 and 4U 1608-52) repeated outbursts every 200-1000 days, which is understood by the limit-cycle of hydrogen ionization states in the outer accretion disk. A third state (very dim state) in Aql X-1 and 4U 1608-52 was interpreted as the propeller effect in the unified picture of LMXB. Cir X-1 is a peculiar source in the sense that its long-term behavior is not like typical LMXBs. The luminosity sometimes decreases suddenly at periastron. It might be explained by the stripping of the outer accretion disk by a clumpy stellar wind. MAXI observed 64 large flares from 22 active stars (RS CVns, dMe stars, Argol types, young stellar objects) over 4 years. The total energies are $10^{34}-10^{36}$ erg $s^{-1}$. Since MAXI can measure the spectrum (temperature and emission measure), we can estimate the size of the plasma and the magnetic fields. The size sometimes exceeds the size of the star. The magnetic field is in the range of 10-100 gauss, which is a typical value for solar flares.

• The Journal of the Acoustical Society of Korea
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• v.30 no.2
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• pp.92-99
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• 2011

In Japan, bang machine has been considered to have problems about not only the impact force and frequency response which are different from the real impact sources such as children's jumping and running, but also damage in the wooden structure housing. Therefore, a new impactor for lower impact force to prevent demage in wooden structure housing was developed. The impact ball was adopted as the second standard impact source in JIS A 1418-2 and ISO 140-11. In the present study, floor impact sounds generated by impact ball with drop heights in four floors of mock-up building of Building Research Institute (BRI) similar to typical Japanese wooden structure housing were investigated and also compared to jumping sound. The results show that Impact ball sound dropped at 10 cm to 30 cm was most similar to jumping sound. And The impact sound levels at 250 and 500 Hz were more sensitive to drop height than other lower frequencies. The error that may occur from the difference of height of 10 cm up and down based on the standard drop height caused by the impact ball operated by human hands was approx. 1 dB or less only in its value of characteristic, but it must be carefully taken into Impact ball in the Korea Standard.

• Journal of Wetlands Research
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• v.21 no.4
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• pp.334-343
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• 2019

A lab-scale vertical flow subsurface (VFS) wetland composed of three parallel columns with polypropylene synthetic fiber as main substrate was operated. Piggery stormwater diluted from swine excreta was fed to the wetland on the basis of three different hydraulic regimes or hydraulic retention time (HRT) of 2, 4, and 8 days with daily internal recirculation. Then, monitoring of common water quality parameters was carried out. Unexpectedly, an increase of effluent COD concentration accompanying the appearance of foams was observed during a distinct period in the wetland with HRT 2, 4, and 8 days, successively. Subsequently, a series of experiments was conducted to investigate the origin of the foams. Foams and the increase of COD concentration were found to be induced by the release of organic matter from the synthetic polypropylene fiber which was fed with piggery stormwater. Meanwhile, nitrogen removal was found to be enhanced during a period which overlapped the distinct foaming period signifying that foaming played two important functions in biological nitrogen removal. Foams which form rapidly and then burst easily could hold up and then release oxygen for nitrification. Foams which contain organic surfactants could serve as carbon sources for denitrification as well. Hence, nitrogen removal was enhanced during the foaming stage. After that, COD concentration decreased slowly to a level prior to the foaming stage, and nitrogen removal efficiency declined as well.

• Journal of the Korean Geotechnical Society
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• v.29 no.9
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• pp.17-29
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• 2013

The geophysical methods have an advantage for investigating the wide area with low cost, and thus the application of these methods has been increased. The objective of this paper estimates the characteristics of alluvium through the geophysical methods including elastic wave, electrical resistivity and ground penetration radar. And the standard penetration test is also carried out for verifying the geophysical data with comparison. The sources of elastic wave method are divided into hammer and sissy and the electrical resistivity method is applied with different sizes, shapes and arrays of electrode for deciding the effective way. The center frequency is determined to be 270 MHz for considering the characteristics of soil. The results of ground penetration radar are also compared with those of standard penetration test. The high resolution shows when the source is a sissy in elastic wave method, however, the water level is not identified. In the electrical resistivity method, the non-polarizable electrode and schlumberger array show highly reliable data and the resolution of ground penetration radar is low. Thus, the results of this study are widely applied for determining the appropriate method when investigating the characteristics of alluvium.

• Korean Journal of Clinical Pharmacy
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• v.19 no.1
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• pp.1-17
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• 2009

Adverse drug reactions (ADR) caused by inappropriate prescription are responsible for major socioeconomic loss. Drug-drug interactions (DDI) has been recognized as a major part of ADRs and, therefore, healthcare professionals should prevent possible DDIs to minimize preventable ADRs. This study aimed to examine DDI information in drug information references and Korea Food & Drug Administration (KFDA) drug labeling information. Drug ingredients from the formulary of Health Insurance Review and Assessment Service in Korea (HIRA) were included for the study. DDI information source used for the study were Micromedex Drugdex and Drug Information Facts (DIF) with the DDI severity level of "moderate" or more. The DDI information in KFDA drug labeling were collected and compared. Drug ingredients were classified with KFDA Drug Classification and ATC Classification of WHO for the analysis. Among the total 1,355 drug ingredients satisfying inclusion criteria, 738 ingredients involved at least one DDI, which was described in Micromedex and/or DIF. Drug Ingredients of 176 involved DDI only described in KFDA drug labeling, but not Micromedex nor DIF. Drug ingredients of 35 which DDIs were described in Micromedex or DIF did not have DDI based on KFDA drug labeling. Micromedex and DIF retrieved 7,582 and 3,071 DDIs, respectively 57.6% and 58.5% of DDIs were also described in KFDA drug labeling. Central nervous system (CNS) drugs, cardiovascular system (CVS) drugs and the antiinfectives appeared to have higher frequency of DDIs among all drug classes. The highest number of DDIs with high severity level ("contraindicated" or "major") were the DDIs of CNS drugs. The antiinfectives are the second drug group having serious DDIs. The DDI pairs of the CNS drug and the antiinfective had the highest contraindication risk (13.6%). DDI information from Micromedex and DIF were not consistent with the result that only 465 ingredients' DDIs are common in both literature (total DDI numbers were 715 vs 488, respectively). And 1,652 DDI information are common in both references among 7,582 vs 3,071 DDIs, respectively. Only 55.2% of DDI information in the database contained in the KFDA drug labeling. Prescribers and pharmacists should pay attention to the drugs for CV system, CNS and infections because of higher risk of possible DDIs compared to other drug classes. KFDA drug labeling is not likely to be recommended as a good information source for DDI due to significant inconsistency of information. Drug information providers should be aware that DDI information from different sources are not consistent and therefore multiple references should be used.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.669-675
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• 2006

Toluene of aromatic compounds, MEK of ketones and IPA of alcohols were extremely used as VOCs (Volatile Organic Compounds) on the getting into step with industrial process. The adsorption characteristics of three component solvent vapors (Toluene-MEK-IPA) on the activated carbonaceous adsorbents such as AC, ACF and AC+ACF were investigated in a stainless steel fixed bed adsorption experimental apparatus in order to identify those carbons for eliminating and recovering solvent vapors from industrial emission sources. The used activated carbonaceous adsorbents were pelletized commercial activated carbon and activated carbon fiber. The breakthrough curves and adsorption capacity have been obtained at atmospheric pressure in a adsorption fixed bed. It has been found that non-polar and larger molecules have been adsorbed better than polar and smaller molecules. Especially, alcohols and ketones were poorly adsorbed due to competitive adsorbability in ternary mixture system. However, it could be overcome by employment of activated carbonaceous adsorbent which have different porosity distribution appropriately.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10C
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• pp.967-983
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• 2003

In wireless spread-spectrum communication systems utilizing PN (pseudo noise) sequences, a variety of noise sources from the channel affect the data reception performance. Among them, in this paper we are concerned with the narrowband interference that may arise from the use of the spectral bands overlapped by the existing narrowband users or the intentional jammers as in military communication. The effect of this interference can be reduced to some extent at the receiver with the PN demodulation by processing gain. It is known, however, that when the interferers are strong, the reduction cannot be sufficient and thereby requiring the extra use of narrowband interference cancellers (NIC's) at the receivers. A class of adaptive NIC's are studied here based on different two cost functions. One is the chip mean-squared error (MSE) computed prior to the PN demodulation and used in the conventional cancellers. Since thses conventional cancellers should be operated at the chip rate, the computational requirements are enormous. The other is the symbol MSE computed after the PN demodulation in which case the weights of the NIC's can be updated at a lot lower symbol rate. To compare the performance of these NIC's, we derive a common measure of performance, i.e., the symbol MSE after the PN demodulation. The analytical results are verified by computer simulation. As a result, it is shown that the cancellation capability of the symbol-rate NIC's are similar or better than the conventional one while the computational complexity can be reduced a lot.