• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.720-726
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• 2009

Hydrodynamic similarity was investigated in pressurized three-phase slurry bubble columns by selecting the bubble holdup and pressure drop as objective functions, for the effective design and scale-up of it. In addition, effects of operating variables on the bubble holdup with variation of column diameter were also analyzed. Gas velocity($U_G$), viscosity(${\mu}_{SL,eff}$) and surface tension(${\rho}_{SL}$) of slurry phase, density difference between the slurry and gas phases(${\rho}_{SL}-{\rho}_G$) depending on the operating pressure, pressure drop per unit length(${\Delta}P/L$), column diameter(D) and gravitational acceleration(g) were chosen as governing parameters in determining the bubble holdup and pressure drop in the column. From the dimensional analysis, four kinds of dimensionless groups were derived from the 7 parameters and 4 fundamental dimensions. Effects of dimensionless groups such as Reynolds, Froude and Weber numbers on the bubble holdup in the column were discussed. The pressure drop and bubble holdup could be predicted from the correlation of dimensionless groups effectively, which could be used as useful information for the design and scale-up of pressurized slurry bubble columns.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.867-876
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• 2016

In accordance with the changing of society, remarkable increase in knowledge and information, the competencies to choose and use proper information in various domains are considered as an important skill. As one of the methods in developing these competencies, it is emphasized that a problem-based learning can make student understand and use knowledge by solving the contextualized problem. However, it is skeptical of learner's development of competencies to use knowledge by solving well-defined given problem. Therefore it is required that students be allowed to develop the competency to find problem through experiences to determine and evaluate the purpose of the problem and method. The purpose of this study is to understand how undergraduate students use science or technology in finding a problem. In this line, this study articulated four cases conducted by participants who engaged in convergence teaching-learning program. And this study investigated the participants' process of problem-finding, method and reason to apply science or technology. The results were drawn by analyzing interviews and written data, including their proposal, a poster, and final reports. Participants changed the form of problem from initial ill-structured one into a concrete one, where the participant could derive a detailed solution. Science or technology applied as the detailed example to convert problem into a concrete form, or as the analyzing tool or theoretical background of problem to make a link with other domain. Their reason of applying science or technology could be summarized in 'personal interest based on prior experience' and 'alternatives to resolve a dissatisfaction.' Based on the result, this study suggests holistic approach that is included in both intuitive thinking and logical thinking and metacognitive regulation to stimulate problem-finding in problem-based learning program.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.3
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• pp.160-180
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• 2012

We have studied the eukaryotic plankton species diversity to compare the community structure of fresh and brackish waters in the lower reaches of the Nakdong River using metagenomic methods. We constructed 18S rDNA clone libraries of total DNAs extracted from environmental water samples collected at Mulgeum (MG100929, fresh) and Eulsukdo bridge (ES, brackish). Through the steps of colony PCR, PCR-RFLP, sequencing and similarity analysis, we discovered the diverse species composition of eukaryotic plankton. Total 338 clones (170 at MG100929 and 168 at ES) were analyzed, and then we found 74 phylotypes (49 for MG100929 and 25 for ES). From the phylogenetic analysis, we confirmed various eukaryotic plankton of broad range of taxonomic groups, including Stramenopiles, Cryptophyta, Viridiplantae, Alveolata, Rhizaria, Metazoa, and Fungi. We also found several unreported species in Korea and candidates of new taxonomic entities at levels higher than genus. Especially, the cryptic species diversity including unreported phylotypes of Pirsonia (Stramenopiles) and Perkinsea (Alveolata) suggests that the molecular monitoring method can produce new informative biological data in monitoring the changes in the Nakdong River Mouth ecosystem.

• Journal of Digital Convergence
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• v.15 no.8
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• pp.511-516
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• 2017

The study conducted a systematic analysis through systematic literature to explore trends in physical activities and trends in the elderly and smart health care sector. Based on the research data collected from 2006 to 2017, the research paper was selected as an analysis data base and collected data from the patented patent data registered to the Patent Office. Based on the combination of the aged, physical activities, IT, IoT, and healthcare, the research identified the research trends and subjects through the analysis and analysis of subjects based on a total of 102 academic journals and 79 patents. First of all, the academic research published a surge in 2010 research in 2006, and it has emerged as an area of continuous interest in academia until 2017. Meanwhile, patents for patents soared in 2012, according to the company's patent. Second, research shows that studies are being conducted in five areas of research. Service design, monitoring systems, systems, policies, and other studies. In the case of patents, three types of patents were classified as patents, devices and information related to information. Subsequent studies will be deemed necessary to verify the effectiveness of the smart health care technology to enhance the health of the elderly.

• Journal of Korean Medicine for Obesity Research
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• v.17 no.1
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• pp.37-45
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• 2017

Recently the global epidemic problem of obesity has stimulated intense interest in the study of physiological mechanisms using animal models as a way to gain crucial data required for translation to human studies. Panax ginseng has been reported to have anti-obesity or antidiabetic effects in many animal studies; however, there have been few studies investigating human obesity. Herein, we will assess and examine the evidence supporting the anti-obesity effect of Panax ginseng in animal models with respect to anthropometric and metabolic outcomes. We will include controlled, comparative studies assessing the effect of Panax ginseng in preclinical studies of obesity. Panax ginseng will be administered during or following the induction of experimental obesity. The primary outcome measure will be anthropometric assessment and the secondary outcome measures will include adipose tissue weight, total amount of food consumed and metabolic parameters. We will search MEDLINE, Embase, PubMed, Web of Science, and Scopus without language, publication date, or other restrictions. Ethical approval will not be necessary as the data collected in this study will not be individual patient data, consequently there will be no concerns about violations of privacy. After finishing the whole procedure, the results will be disseminated by publication in a peer-reviewed journal or presented at a relevant conference. This protocol has been registered on the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES) website (http://www.camarades.info).

• Journal of the Korean Society of Radiology
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• v.11 no.2
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• pp.79-85
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• 2017

The purpose of this study is to investigate the cause analysis according to the difference between the pre exposure tube voltage and actual exposure tube voltage in mammography in connection with breast pressure thickness, breast size and body mass index and to find the improvement. The study tracked 377 women age 40 and older among the mammography examiners conducted by the National Health Insurance Corporation. It was analyzed that breast pressure thickness, breast size and body mass index according to the difference between the pre exposure tube voltage and actual exposure tube voltage among the parameters of dose report been sent to the picture archiving communication system with reference to the image with cranio-caudal projection in mammography. As are result, it shows that the thicker the breast thickness, smaller the breast size and lower body mass index, the higher the difference of tube voltage. In conclusion, the minimum tube voltage of mammography machine should be reset in order to set the tube voltage according to breast pressure thickness and breast size that are suitable for our country in mammography, in addition, it was considered that radiologist should make an effort to reduce radiation exposure and make a good quality image with reducing the difference of mammography condition by making a correct exposure condition in case of examining the patients with thin breast pressure and small breast size.

• Journal of Nutrition and Health
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• v.37 no.8
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• pp.688-700
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• 2004

This study was conducted to analyze how appropriate the on-line nutrition information was externally as a web information. Four-hundred-ninety-seven web sites from 5 internet search engines (Yahoo, Empas, Nate, Hanmir, Naver) were selected on the basis of April 25th, 2004. The skillful personnels monitored them about 8 evaluating categories: clarity, purpose, authority, durability, advertisement, privacy and/or security, responsibility, and contents. Forty percent of the selected web sites were operated by the companies which had commercial purpose like internet shopping malls and 5.6% by academies, societies, research institutions, schools/colleges and public institutions. Most of web sites (76.1 %) were managed for advertisements and sales of companies' commodities, and 32.6% had the food and nutrition information as first purpose. Ninety-three percent of web sites were targeted to healthy individuals through whole life cycle. Specifically, there were lots of web sites for the obesity which were offered by diet related companies. Of the 497 web sites, 193 mentioned the name providing the nutrition information, but only 1/3 had reliability on their specialty. As a source of nutrition information, 52.7% of web sites were using 'books of the major field' and 42.0% 'newspapers' and 23.7% 'broadcasting', respectively. Most web sites mentioned 'setting-up date' but not 'renewal date'. Thirty-six percent of web sites took '2 - 3 days' for the operators to answer the questions through the bulletin. Forty-seven percent of web sites answered' 1 - 10 questions' per 1 week, but 40.1 % of them didn't answer for a week at all. There were 118 web sites (23.7%) to record the connected frequencies and 36.0% of them put the advertisements. Around 96% of web sites mentioned feedback addresses. Among the menus of web sites, 68.0% were about self-advertisement and 64.0% about nutrition information. Each web site was scored to judge its external quality according to the operators by selecting 13 items. Web sites managed by public institution had highest scores (9.5), and lowest in private vendors', food companies' and individual web pages. Among search engines, Naver got the highest score of 7.0 and Nate the lowest one of 6.1. As it was only the pilot study, there were several limits in evaluating tools, time and monitored quantity. To make monitoring of on-line nutrition informatiions actively, standardized monitoring forms might be developed under the integrated studies.

• Journal of The Korean Association For Science Education
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• v.38 no.5
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• pp.667-680
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• 2018

The purpose of this study is to investigate 1) the types of knowledge students ask for in their reading comprehension of science textbooks using an online annotation system, 2) the accuracy of the knowledge provided by the students to their peers, 3) the frequency of knowledge sharing behaviors, 4) the evaluation of the effect of collaborative reading, and 5) the trust among peers as knowledge sharers. Questions made by 241 students in the second grade of middle school using an online annotation system in two chapters of the science textbook were analyzed using Bloom's revised taxonomy and their answers were grouped according to five accuracy categories. Also, questionnaires for the evaluation of the effectiveness of collaborative reading comprehension and of trust among the students were used. The students asked their peers 'understanding questions' which comprised almost 80% of the total questions they made and were similar with individual metacognitive strategies for reading comprehension. Of the total threads, 71% has scientifically correct threads shared by the students. The frequency of the knowledge sharing behaviors was high but this was affected by the rewards (point system). Students evaluated that collaborative reading comprehension conducted through an online annotation system were helpful in their learning. In addition, the ratio of students trusting their peers who did the knowledge sharing is over 80%. This study shows that when students use an online annotation system, they can fill one another's cognitive gaps in the reading process by sharing knowledge. Also, collaborative reading using an online annotation system has proved that cognitive individualization is possible through sharing knowledge interactively and dynamically, unlike reading hard copies of textbooks which are a one way information transfer.

• Progress in Medical Physics
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• v.12 no.2
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• pp.185-191
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• 2001

The virtual compensator which are realized using a multileaf collimator(MLC) and three-dimensional radiation therapy Planning(3D RTP) system was designed. And the feasibility study of the virtual compensator was done to verify that it can do the function of the conventional compensator properly. As a model for the design of compensator, styrofoam phantom and mini water phantom were prepared to simulate the missing tissue area and the calculated dose distribution was produced through the 3D RTP system. The fluence maps which are basic materials for the design of virtual compensator were produced based on the dose distribution and the MLC leaf sequence file was made for the realization of the produced fluence map. Ma's algorithm were applied to design the MLC leaf sequence and all the design tools were programmed with IDL5.4. To verify the feasibility of the designed virtual compensator, the results of irradiation with or without a virtual compensator were analyzed by comparing the irradiated films inserted into the mini water phantom. The higher dose area produced due to the missing tissue was removed and intended regular dose distribution was achieved when the virtual compensator was applied.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.987-993
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• 2002

최근 들어 전자상거래의 급속한 발달로 전 세계적으로 수송 물동량이 급격히 증대되고 있고, 이로 인해 택배사업이 대단히 활성화되고 있다. 출발지와 목적지가 서로 상이한 무수히 만은 수송 요구가 들어오면 수송 요구화물의 신속한 집배송을 위한 배차계획 및 수송계획을 세우는 것이 택배회사의 주요 업무이다. 이러한 배차 계획 및 수송 계획을 어떻게 수립하느냐에 따라 전체 수송비용뿐만 아니라 고객들의 서비스 수준에 상당한 영향을 미치게 된다. 그러나 이러한 운영적 차원에서의 의사결정 이전에 훨씬 중요하게 고려해야 할 내용이 택배네트워크의 설계 문제이다. 이러한 택배네트워크의 설계에는 터미널 개수 및 위치를 결정하는 전략적 문제와 영업소들을 터미널에 할당하는 전술적 문제로 구분될 수 있다. 현재 우리 국내에는 크고 작은 수많은 택배사업자들이 있으나, 그 중에서 비교적 규모가 큰 주요 택배회사들은 대부분 전국에 걸쳐 다수의 터미널을 설치하여 두고 수송화물의 집배송을 위한 물류거점으로 운영하고 있다. 이와 같은 터미널 위치 및 개수가 정해진 상태에서 전국에 걸쳐 분포되어 있는 영업소들을 어떤 터미널에 할당하여 처리되도록 하느냐의 여부는 수송비용 측면에서뿐만 아니라 고객들에 대한 서비스 측면에서 대단히 중요한 의사결정 중의 하나이다. 본 연구에서는 비용과 시간을 고려하여 전국에 걸쳐 분포되어 있는 영업소들을 어떤 터미널에 할당해야 하는지를 결정하기 위한 수리적 모형을 제시하고, 이에 대한 탐색적 해법을 제시하며, 국내의 택배회사 사례를 대상으로 모형을 적용해 보고자 한다.무가 많이 발생하는 유통 분야의 프랜차이즈 산업을 대상으로 기업정보시스템 구현 및 경쟁력 강화를 뒷받침하기 위해서, 기업간 프로세스 협업(collaboration) 부분의 데이터 및 서식, 이를 취급하는 기능과 프로세스에 대란 분석을 통해 업무 프로세스 모델링 방법론과 관련한 모델링 지침 및 메타모델을 이용한 표준 업무 프로세스 모델을 개발하여 기업간 업무 프로세스 표준화에 대한 체계적인 관리에 대한 방안을 연구하고자 한다.의Bullwhip effect를 감소시킬 수 있는 장점이 있다. 동시에 이것은 향후 e-Business 시스템 구축을 위한 기본 인프라 역할을 수행할 수 있게 된다. 많았고 년도에 따른 변화는 보이지 않았다. 스키손상의 발생빈도는 초기에 비하여 점차 감소하는 경향을 보였으며, 손상의 특성도 부위별, 연령별로 다양한 변화를 나타내었다.해가능성을 가진 균이 상당수 검출되므로 원료의 수송, 김치의 제조 및 유통과정에서 병원균에 대한 오염방지에 유의하여야 할 것이다. 확인할 수 있었다. 이상의 결과에 의하면 고농도의 유기물이 함유된 음식물쓰레기는 Hybrid Anaerobic Reactor (HAR)를 이용하여 HRT 30일 정도에서 충분히 직접 혐기성처리가 가능하며, 이때 발생된 $CH_{4}$를 회수하여 이용하면 대체에너지원으로 활용 가치가 높은 것으로 판단된다./207), $99.2\%$(238/240), $98.5\%$(133/135) 및 $100\%$ (313)였다. 각