• Title/Summary/Keyword: Reduction effects

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A Study on the Urea-SCR System for NOx Reduction of a light-Duty Diesel Engine (소형 디젤엔진의 NOx 저감을 위한 Urea-SCR 시스템에 관한 연구)

  • Nam Jeong-Gil
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.5
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    • pp.57-63
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    • 2005
  • The effects of an urea injection at the exhaust pipe for a 4-cylinder DI(Direct Injection) diesel engine were investigated with the parameters such as urea-SCR(Selective Catalytic Reduction) and EGR system. The urea quantity was controlled by NOx quantity and MAF(Manifold Air Flow). The urea injection quantity can be controlled with the urea syringe pump, precisely. The effects of NOx reduction for the urea-SCR system were investigated with and without ECR engine, respectively. It was concluded that the SUF(Stoichiometric Urea Flow) is calculated and the NOx results are visualized with engine speed and load. Furthermore, the NOx map is made from this experimental results. It was suggested, therefore, that NOx reduction effects of the urea-SCR system without the EGR engine were better than that with the EGR engine except of low load and low speed.

A Study for Dose-Reduction of Antipsychotics in Chronic Schizophrenics (만성 정신분열병 환자에서 항정신병약물 감량에 관한 연구)

  • Hwang, Tae-Yeon;Lee, Min Soo;Kim, Hyeong-Seob
    • Korean Journal of Biological Psychiatry
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    • v.5 no.2
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    • pp.263-277
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    • 1998
  • Conventional high-dose antipsychotics tend to result in more side effects, negative symptoms and dysphoria, and at the same time lower the cognitive function which is already impaired in most schizophrenics. Florid psychotic symptoms, negative symptoms and cognitive impairment greatly impede psychosocial performance and eventual reintegration into society. The reduction of symptom and the improvement of cognitive funtions and social skills are therefore central to the psychiatric rehabilitation process. The purpose of this study was to evaluate the dose-reduction effects of antipsychotics on chronic schizophrenics prescribed conventional high-dose antipsychotics more than 1,500mg equivalent of chlorpromazine. Fifty-one chronic schizophrenics who maintained high-dose antipsychotics for more than three months were randomly assigned to two groups : 20 patients comprised the dose-maintaining group and 31 patients made the dose-reduction group. Over a sixteen weekperiod Positive and Negative Syndrome Scale(PANSS), Extrapyramidal Symptom(EPS), Nurses' Observation Scale for Inpatient Evaluation(NOSIE-30), Continuous Performance Test(CPT), Quality of Life(QOL), and haloperidol/reduced haloperidol blood levels were determined at the base line and after 2, 4, 6, 8, 12, 16 weeks to evaluate the dose reduction effects of high-dose antipsychotics. The results were as follows : 1) Dose-reduction is highly effective in reducing positive and negative symptoms, and general psychopathology. Effects were most prominent at 8, 12, 16 weeks. Among the dose reduction group, positive symptoms in positive symptom group and negative symptoms in negative symptom group were more reduced. 2 Extrapyramidal symptoms showed no significant difference between two groups. But the EPS was reduced time after time within two groups. 3) Hit rates of Continuous Performance Test, which indicate attentional capacity, increased significantly after dose reduction. 4) Haloperidol and reduced haloperidol blood levels decreased until the 4th week, after which they were constant. 5) Total scores of Nurses' Observation Scale for Inpatient Evaluation were unchanged between the two groups. But among the indices, social interest and personal neatness were improved in the dose-reduction group and retardation was aggrevated in the dose-maintaining group. 6) Total quality of life scores were unchanged between two groups. But in the dose maintaining group, satisfaction scores of attention, autonomy, and interpersonal relationship decreased progressively. These findings suggest that the dose reduction of antipsychotics for chronic schizophrenics on programs of high-dose antipsychotics were effective. Dose reduction should therefore be implemanted to spread the rehabilitation and improve quality of life for chronic schizophrenics.

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Qualitative Analysis of the Experiences in Mindfulness-Based Stress Reduction(MBSR) on Hwa-Byung Patients (화병환자의 마음챙김에 기초한 스트레스 감소 프로그램(Mindfulness-based Stress Reduction:MBSR)경험에 관한 질적 연구)

  • Song, Seung-Yeon;Cho, Hyun-Ju;Kim, Sang-Young;Kim, Jong-Woo
    • Journal of Oriental Neuropsychiatry
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    • v.23 no.4
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    • pp.153-158
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    • 2012
  • Objectives : The objective of the study is to examine what effects the Mindfulness-based stress reduction program can have on Hwa-byung patients. Methods : Ten Hwa-byung patients have participated in this 8-week Mindfulness-based stress reduction program for Hwa-byung. In addition, participants were interviewed regarding the experiences from the changes during meditation or everyday life. Data were collected though a consumer panel and individual interviews. Responses were coded using Consensual Qualitative Research (CQR) methodology. Results : The experiences were categorized into 7 domains and divided to 23 categories. Results showed the psychotherapeutic effects of Mindfulness-based stress reduction program, specifically, positive cognitive changes, emotional stability, and changes in attitude. Also, all participants reported improvement of anger management skill and feeling of tranquility. This means that the Mindfulness-based stress reduction program can relieve the symptoms of Hwa-byung. Conclusions : Mindfulness-based stress reduction program makes changes about emotion, physical symptoms, cognition and personal relationship. This program can be applied to psychotherapy for Hwa-byung.

Effects of Organic Farming on Greenhouse Gas Emission Reduction (유기농업의 온실가스 감축효과)

  • Kim, Chang Gil;Jeong, Hak Kyun;Kim, Yong Gyu
    • Journal of Climate Change Research
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    • v.7 no.3
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    • pp.335-339
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    • 2016
  • The purpose of this study is to analyze effects of greenhouse gas reduction in organic agriculture. To accomplish the objective of the study, a field survey was conducted. Based on the field survey results, LCA method was used to estimate the greenhouse gas emission. The farmer survey and LCA estimation data were provided by The Foundation of Agricultural Technology Commercialization and Transfer. The GHG estimation results showed that GHG emission of organic farming is less by 10.6~89.3% when compared with the conventional farming. In addition, the economic value of greenhouse gas reduction in organic farming amounts to 1,097 million won. Based on major findings, in response to national greenhouse gas reduction target, it is needed to expand organic farming, supporting organic farmers' income.

Experimental study on the aerodynamic effects of slots at a rotor tip (로터 끝 슬롯의 공기역학적 효과에 대한 실험 연구)

  • Yisu Shin;Seungcheol Lee;Jooha Kim
    • Journal of the Korean Society of Visualization
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    • v.21 no.3
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    • pp.39-48
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    • 2023
  • In this study, we investigate the effects of slots installed on the tip of a rotor blade on aerodynamic characteristics. The slots weaken the strength and spatial coherence of the tip vortex at early vortex age and accelerate the dissipation of the generated tip vortex. Accordingly, the turbulence intensity of the rotor wake is reduced at both near and far wake, which leads to a reduction in broadband noise. Tonal noise is also reduced by mitigation of tip vortices, but tonal noise reduction is limited to a narrower range of azimuths than broadband noise due to the extinction of tip vortices. In addition, slots reduce both mean thrust and thrust fluctuations. Reduction in thrust fluctuations leads to a reduction in blade loading noise, resulting in a reduction in tonal noise.

A study on effects of resting facility on the Reduction of Disasters in Construction Projects (건설 사업장 휴게시설이 재해감소에 미치는 영향에 관한 연구)

  • Kim, Jong-Min;Kang, Kyung-sik
    • Journal of the Korea Safety Management & Science
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    • v.19 no.4
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    • pp.141-148
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    • 2017
  • This researcher selected basic variable to investigate the effective relations of establishment and management of resting facility on reduction of constructional disasters and safety accidents and improvement of working efficiency for construction workers. Based on the measured variables, this researcher investigated phenomenon, recognition and satisfaction for using and demanding resting facility by long-term construction in construction site for workers of huge construction site in Seoul, conducted survey of total 219 questionnaires so as to grasp implications of workers' resting facility demanded in long-term huge construction site and effects on reduction of disasters and conducted structural equation analysis. As a result, resting faciity factor, management factor, and hygienic service factor were significant and resting and food factors were not significant. Therefore, it's expected to reduce personal disaster by improving quality of constructional resting facility, hygienic service, and resting facility management and especially, resting facility management factor makes lots of effects on prevention of personal disasters, so it was a strongly main factor. By suggesting the guideline of establishment and management service of proper resting facility through this research, positive recognition and constructional disaster reduction can be expected in construction site.

The Impact of Input and Output Tariffs on Domestic Employment across Industries: Evidence from Korea

  • Jang, Yong Joon
    • Journal of Korea Trade
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    • v.24 no.8
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    • pp.1-18
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    • 2020
  • Purpose - This paper examines how differently output and input tariffs affect domestic employment across industrial characteristics of comparative advantage such as labor quality and capital intensity. Design/methodology - The paper focuses on 453 Korean industries from 2007 to 2014 because Korea is a typical example of a natural resource-scarce open economy and experienced the transition of the export pattern from labor intensity to technology intensity during this period. Findings - The results show that input tariff reduction stimulated total employment, focusing on the early 2010s, while the effects of output tariff reduction were statistically insignificant in general. However, the stimulation effects of output tariff reduction on employment were found in comparative advantage industries with greater labor quality and capital intensity. As for input tariff reduction, its stimulation effects on employment were more prominent in comparative disadvantage industries with lower labor quality and capital intensity. Originality/value - These results provide significant implications for natural resource-scarce open economies which are experiencing the transition of the export pattern from labor intensity to technology intensity and the unequal distribution of income after trade liberalization: imported intermediate inputs has become increasing important, leading to trade effects on employment and alleviation of income inequality.

Effects of Ionic Strength, Background Electrolytes, Heavy Metals, and Redox-Active Species on the Reduction of Hexavalent Chromium by Ecklonia Biomass

  • PARK DONGHEE;YUN YEOUNG-SANG;JO JI HYE;PARK JONG MOON
    • Journal of Microbiology and Biotechnology
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    • v.15 no.4
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    • pp.780-786
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    • 2005
  • The biomass of the brown seaweed, Ecklonia, was used to remove Cr(VI) from wastewater. Previously, Cr(VI) was removed through its reduction to Cr(III) when brought into contact with the biomass. In this study, the effects of ionic strength, background electrolytes, and Cr(III), Ni(II), Zn(II), and Fe(III) on the Cr(VI) reduction were examined. An increased ionic strength inhibited the Cr(VI) reduction. The presence of other heavy metals, such as Cr(III), Ni(II), or Zn(II), only slightly affected the Cr(VI) reduction, while Fe(III) enhanced the reduction. Although the above various parameters could affect the reduction rate of Cr(VI) by Ecklonia biomass, these effects were relatively smaller than those of pH and temperature. In addition, the previously derived rate equation was found to be applicable over a range of ionic strengths and with different background electrolytes. In conclusion, Ecklonia, bioniass may be a good candidate as a biosorbent for the removal of Cr(VI) from wastewaters containing various other impurities, and scale-up to a practical process may be accomplished using the previously derived rate equation.

Effects on the Accident Reduction of Red Light Camera Using Empirical Bayes Method (경험적 베이즈 방법을 이용한 무인신호위반단속장비의 사고감소 효과)

  • Kim, Tae-Young;Park, Byung-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.6
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    • pp.46-54
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    • 2009
  • This study deals with the effects on the accident reduction according to the installation of RLC (red light cameras). The objective is to analyze the effects on the accident reduction using EB (Empirical Bayes) method. In pursuing the above, the study uses the 728 accident data occurred at the 28 intersections which RLC are installed. The main results are as follows. First, the effects of accident reduction were analyzed to be 20.74% by simple before-after study method. Second, the safety performance functions (SPF) were developed by the Poisson and negative binominal regression models, and since the over-dispersion parameter was close to zero, Poisson model was evaluated to be more appropriate than the negative binominal model. Also, the Poisson model was analyzed to be statistically significant because its ${\rho}^2$ value was 0.409. Finally, the results of analysis using an EB method showed that the accidents were reduced by range from 3.89 to 29.23%.

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Selective catalytic reduction of NO by hydrocarbons over $Cu/Al_2O_3$ catalysts

  • Nam, Chang-Mo;Bernard M. Gibbs
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.4 no.4
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    • pp.201-208
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    • 2000
  • The reduction of NO by hydrocarbons was investigated over Cu/Al$_2$O$_3$catalysts using a stainless steel flow reactor under highly oxidising diesel exhaust conditions(up to 15%). Three different Cu loadings(1,5 and 10wt.%) on an $Al_2$O$_3$support were prepared and characterized using spectroscopic techniques. The catalytic activity tests show that different Cu loadings as well as temperature, oxygen, and hydrocarbon concentration levels significantly influence the NO reduction. Increasing Cu loadings up to 5 and 10wt.% decreases the catalytic activities for NO reduction due to the formation of a bulk crystalline CuO phase, as observed from XRD and SEM images. In particular, the visualization of the copper dispersion on the surface using the SEM-BEI technique provides information on the extent of copper saturation, particle size, and the effects on NO reduction. However, the lower Cu loading(1 wt.%) increases the catalytic activity with a temperature window of 720-810K, thereby favoring the formation of well dispersed isolated Cu species, e.g. Cu(sup)2+ ions, which is related to selective NO reduction. The effects of other reaction parameters, such as oxygen, the hydrocarbon level and type, and byproduct emissions are further discussed.

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