• Resources Recycling
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• v.16 no.5
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• pp.65-70
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• 2007

This study presents the findings of the experiments that were conducted on single- and multi-stage solvent extractors using the stimulus-response method, with the am of identifying flow characteristics of the material inside the mixer-settler-type extractor. The results of this study show that the response characteristics of a single-stage mixer is the same as that of a completely stirred tank reactor (CSTR), and that the lag time of a mixer-settler-type extractor increases with the number of its extraction stages. The experimental data for the single- and multiple-stage extractors were analyzed using K-RTD, a response analysis program, to obtain a retention time distribution (RTD) model of one-stage and four-stage extractors. The correlation coefficient between the calculated values and the experimental data was 0.963 for the one-stage extractor and 0.995 for the four-stage extractor, showing quite a good correlation.

• Food Science and Preservation
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• v.10 no.3
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• pp.376-380
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• 2003

This aims is to estimate the consumers' preference on the brand rice using factor analysis, completed research on the consumption of brand rice revealed that the household supply in the Seoul area is increasing. An analysis whether housewives' preference in chosing the brand of rice was developed through the consumption experience and re-purchase intention investigation for the brand rice. Also the paper analyzed the consumers' preference using the logit and probit model. Number of respondents who participated in the study(95 ％) totaled 1000 and the sampling method utilized was the multistage stratification and assignment abstraction. Results showed that the preference of housewives' depends on age, education and level of income. Such that as age, education, income level increase so thus their preference for brand rices also increase. Also the re-purchasing of brand rice is high when housewives have a higher educational attainment and prefers to go to work. Conclusively, the long-term sale view for brand rice is closely related to the economic conditions of a household. Hence, with the economic growth, there is a possibility that consumption of brand rice would increase compared to the ordinary rice. We can propose the following political intent from analysis of these results. First, There is a need for continuous public information as reinforcement for brand rice. Second, Marketing operation reinforcement could also be done for customer class security etc.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4B
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• pp.162-169
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• 2005

Network traffic measurements show that the data traffic on packet switched networks has the self-similar features which is different from the traditional traffic models such as Poisson distribution or Markovian process model. Most of the call admission control researches have been done on the performance analysis of a single network switch. It is necessary to consider the performance analysis of the proposed admission control scheme under interconnected switch environment because the data traffic transmits through switches in networks. From the simulation results, it is shown that the call admission control scheme may not operate properly on the interconnected switch even though the scheme works well on a single switch. In this parer, we analyze the cell loss probability, utilization and self-similarity of output ports of the interconnected networks switch by using shared buffer memory management schemes and propose the new call admission control scheme considering the interconnected network switches under self-similar traffic environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2653-2663
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• 1997

The successive and parallel interference cancellation schemes are two well-known types of multi-stage interference cancellation schemes using the conventional correlator receivers as a basic building block, which has been known to significantly improve the performance of DS/CDMA system in the multiple access communication. Performance comparison between these two schemes is made strictly based on the analytical and it has been shown that the successive interference cancellation (SIC) scheme is more resistant to fading than the parallel interference cancellation (PIC) scheme. We further investigate the performance of the successive IC scheme subject to the delay constraint, which may be imposed typically on most of service applications with a real-time transmission requirement, including speech and video applications. Our analysis demonstrates that the performance may be significantly improved by the groupwise successive interference cancellation (GSIC) scheme, which can be properly optimized to meet the given delay constraint.

• Archives of Reconstructive Microsurgery
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• v.7 no.1
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• pp.68-72
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• 1998

With the advent of microvascular free-tissue transfer, this single stage resurfacing method for large scar and soft tissue defects around the wrist in the patients of electrical burn has distinctive advantage over the conventional multistage pedicle-flap transfer. Between 1992 and 1996, we treated 9 cases of 8 patients who had large scar around the wrist due to old electrical burn with free flaps as a preparation of staged tendon graft. Mean age was 30.3 years and average scar area was $6{\times}11cm$. The length of time the injury and free flaps was 9 months on an average. Prior to the free flap, we performed the angiography to all patients in order to evaluate the circulation of the forearm and hand and to choose the recipient vessel. In all cases, proximal ulnar arteries in the forearm remained intact and all radial arteries remained intact in 8 of 9 cases on angiogram. The interosseous arteries were well visualized in all cases. We used the ulnar arteries as a recipient artery. The types of flaps used were f scapular cutaneous flaps, 2 dorsalis pedis flaps and a radial forearm flap. Flap survial was 100 percents with satisfactory functional and cosmetic results. Free flaps using ulnar artery as a recipient artery is one of the useful reconstruction methods for the resurfacing of large scar around the wrist in the patients of old electrical burn.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.367-367
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• 2016

우리나라는 하상계수가 큰 하천의 특성 때문에 콘크리트 구조의 고정보를 설치하여 하천수위를 유지하고, 취수용으로 사용하여 왔다. 그러나 고정보는 유수방해, 토사퇴적으로 인한 홍수위 상승 등의 다양한 문제를 야기시키고 있다. 이에 따라 4대강에는 다양한 형상과 운영방식이 적용된 가동보가 설치되었으며, 소하천과 중규모 하천 역시 하천기능의 복원을 위한 정비사업이 진행되고 있다. 하천관리의 목표는 하천의 이수, 치수 및 생태환경 기능의 종합적이며, 유기적인 관계를 조화롭게 유지하면서 각 기능을 극대화시키는 것이다. 우선, 토사의 퇴적을 사전에 예방하고, 퇴적된 토사는 유수에 따라 배출될 수 있도록 하단방류 형식으로 개선되어야 한다. 또한 홍수기에는 통수가 원활하도록 보의 기능을 해제할 수 있어야 하는 한편, 하류구간이 범람하지 않도록 상류구간에서의 완충기능을 가져야 한다. 이러한 요구조건을 충족하기 위해서 다단형태의 하단방류형 가동보 수문 시스템을 고려할 수 있다. 다단형태의 하단방류형 가동보 수문시스템은 경사 하천에 가동보에 의해 물을 저수하고, 저수된 물을 보 상류에서 유입되는 유입수량 만큼만을 수문 하단 개도부를 통하여 방류하도록 하여, 일정량이 항상 저류되면서 퇴적토사가 배출되도록 하여 수질을 개선하는 방식이다. 본 연구에서는 금강의 지류인 치성천 9Km 구간을 대상으로 HEC-RAS 4.1 모형을 적용하여 하단방류형 가동보를 하류부터 상류구간까지 다단형태로 설치하였을 경우, 하천의 저류와 분배기능 회복에 따른 홍수위 저감 효과를 고정보 설치의 경우와 비교 분석하였다. 홍수소통 능력을 검토하기 위해서 연구대상 구간을 200년 빈도의 확률홍수량 별로 10개 구간으로 나누어 검토한 결과, 고정보 설치의 경우에는 여유고 기준을 초과하는 부분이 나타났으나, 다단식 하단방류형 가동보를 설치하고, 수문개도를 조작하여 운영할 경우에는 여유고 기준을 초과하는 부분이 없어, 홍수위 저감 효과를 기대할 수 있는 것으로 나타났을 뿐만 아니라, 홍수기이후에도 하천유지용수 기준을 만족하는 것으로 나타났다. 또한 설치 및 유지관리의 비용측면과 용수확보 및 홍수피해 절감의 편익측면에서도 50년 운영주기의 비용편익성은 양호한 것으로 나타났으며, 생태환경보전과 친수공간 확보측면의 편익성을 추가로 고려할 경우, 경제성은 충분히 확보될 것으로 판단되었다.

• Journal of Forest and Environmental Science
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• v.27 no.2
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• pp.81-91
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• 2011

An exploratory study was conducted in Gopalganj, a southern district of Bangladesh to explore the role of wild date palm (Phoenix sylvestris Roxb.) husbandry in the rural economy. A total of 36 households in the study area were interviewed using a semi-structured questionnaire. A multistage sampling method with 10% intensity and a semi-structured questionnaire were used for the study. Based on the land holding capacity of the households, the farmers were categorized into five groups as landless, marginal, small, medium, and large. The date palm was distributed over seven different habitats of which roadside support the highest value (31%) followed by agricultural field and orchard (25% each). Though the large category farmers own most of the palms (43%), a considerable portion (562 individuals out of 1980) of it is managed by the landless farmers, who earn a substantial livelihood from the palms. The farmers manage the palm mainly for juice production; juice is either used fresh as drink or after some sort of processing as molasses and/or alcoholic beverage. Date palm husbandry contributes 32,601 Tk., 21,107 Tk., 20,626 Tk., 29,574 Tk. and 35,335 Tk. respectively to the five group seasonally and 50,980 Tk., 77,556 Tk., 90,208 Tk., 112,560 Tk., 140,675 Tk. respectively annually (1 US$ = 70 Tk.). Date palm trees contribute 65.48% of mean annual income to landless farmers followed by 27.21% to marginal farmers. However the poor marketing system result in decreasing the annual return from palm trees. Palm husbandry could be a promising source of rural incomes in Bangladesh if the farmers' traditional management knowledge was linked to more scientific management practices.

• Journal of Preventive Medicine and Public Health
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• v.52 no.2
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• pp.115-122
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• 2019

Objectives: The aim of this study was to assess knowledge, attitudes, and practices regarding tuberculosis (TB) in the general population in Timor-Leste. Methods: In the nationally representative cross-sectional 2016 Timor-Leste Demographic and Health Survey, 4622 men (aged 15-59 years) and 12 607 women (aged 15-49 years) were randomly selected using stratified multistage sampling and interviewed. Results: Overall, 66.9% of men and 62.8% of women were aware of TB, 4.4% of men and 12.6% of women had TB courtesy stigma, and 83.3% of men and 88.6% of women reported intention to receive TB treatment. The $mean{\pm}standard$ deviation overall TB knowledge score was $3.9{\pm}2.0$ (out of 8) among men and $3.0{\pm}1.8$ among women. In a multivariable linear regression analysis, among both men and women, older age, higher education, rural residence, and sources of TB information (family/friends, school/workplace, health care provider, Internet, television, and newspaper) were associated with higher TB knowledge scores. In addition, among women, higher wealth status and having heard about TB from the radio were associated with higher TB knowledge scores. Negative associations with TB courtesy stigma were found for urban residence and having heard about TB from family or friends among men, and for older age, higher TB knowledge, and TB information sources (family/friends and school/workplace) among women. Among both men and women, higher TB knowledge scores and having heard of TB from a health care provider were associated with intention to receive TB treatment. Conclusions: This study identified socio-demographic risk factors for deficiences in population-based TB knowledge in Timor-Leste; these findings should be considered when designing TB communication, prevention, and control strategies.

• Journal of Preventive Medicine and Public Health
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• v.54 no.6
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• pp.431-440
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• 2021

Objectives: The aim of this study was to predict rabies protective behaviors (RPB) based on protection motivation theory (PMT) among fourth-grade students at schools in Chonburi Province, Thailand. Methods: This cross-sectional study was conducted from December 2020 to February 2021. A multistage sampling technique was used for sample selection. The questionnaire was divided into socio-demographic data and questions related to PMT and RPB. Descriptive statistical analysis was conducted using the EpiData program and inferential statistics, and the results were tested using the partial least squares model with a significance level of less than 5%. Results: In total, 287 subjects were included, of whom 62.4% were girls and 40.4% reported that YouTube was their favorite media platform. Most participants had good perceived vulnerability, response efficacy, and self efficacy levels related to rabies (43.9, 68.6, and 73.2%, respectively). However, 54.5% had only fair perceived severity levels related to rabies. Significant positive correlations were found between RPB and the PMT constructs related to rabies (β, 0.298; p<0.001), and the school variable (S4) was also a predictor of RPB (β, -0.228; p<0.001). Among the PMT constructs, self efficacy was the strongest predictor of RPB (β, 0.741; p<0.001). Conclusions: PMT is a useful framework for predicting RPB. Future RPB or prevention/protection intervention studies based on PMT should focus on improving self efficacy and response efficacy, with a particular focus on teaching students not to intervene with fighting animals. The most influential PMT constructs can be used for designing tools and implementing and evaluating future educational interventions to prevent rabies in children.

• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.990-998
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• 2021

Melanin is a natural skin pigment produced by specialized cells called melanocytes via a multistage biochemical pathway known as melanogenesis, involving the oxidation and polymerization of tyrosine. Melanogenesis is initiated upon exposure to ultraviolet (UV) radiation, causing the skin to darken, which protects skin cells from UVB radiation damage. However, the abnormal accumulation of melanin may lead to the development of certain skin diseases, including skin cancer. In this study, the antioxidant and antimelanogenic activities of the cell-free supernatant (CFS) of twenty strains were evaluated. Based on the results of 60% 2,2-diphenyl-1-picrylhydrazyl scavenging activity, 21% 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) scavenging capacity, and a 50% ascorbic acid equivalent ferric reducing antioxidant power value, Limosilactobacillus fermentum JNU532 was selected as the strain with the highest antioxidant potential. No cytotoxicity was observed in cells treated with the CFS of L. fermentum JNU532. Tyrosinase activity was reduced by 16.7% in CFS-treated B16F10 cells (but not in the cell-free system), with >23.2% reduction in melanin content upon treatment with the L. fermentum JNU532-derived CFS. The inhibitory effect of the L. fermentum JNU532-derived CFS on B16F10 cell melanogenesis pathways was investigated using quantitative reverse transcription polymerase chain reaction and western blotting. The inhibitory effects of the L. fermentum JNU532-derived CFS were mediated by inhibiting the transcription of TYR, TRP-1, TRP-2, and MITF and the protein expression of TYR, TRP-1, TRP-2, and MITF. Therefore, L. fermentum JNU532 may be considered a potentially useful, natural depigmentation agent.