• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.27-35
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• 2015

General education is changed by accepting the change in education environment to digital generation, emphasis about student-centered education, and change of teacher's role. E-learning has taken center stage as an effective learning environment but the problems are drawn for the absence of interaction that is important in learning. In this study, on the basis of questionnaire results about learning using website, we operated blended-learning where students come and go in cyberspace and physical space to set up the lesson environment for emphasizing interaction. We selected a control group (N=40) and an experimental group (N=40) from second grade students in a middle school for this research. General instructor-led lessons were implemented in the control group and blended-learning lessons to emphasize interaction between teacher and students were implemented in the experimental group. The experiments were applied to eight class-hours in 'characteristics of matter' unit. We implemented Test of Science Related Attitude (TOSRA) to the students before and after the lessons and administered questionnaire for checking attitude changes and perception in students. The results of the test show that the experimental group students were more encouraged and became more confident and curious about scientific learning than the control group students. The analysis of the interview and results of TOSRA show that blended-learning provided guidance and feedback by the teacher to the experimental group students more than the control group students. Blended-learning is suggested as a learning-method that is helpful in improving scientific attitude in students because it enables them to express their experiences without limit of time-space and promote interaction between teacher and students.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.785-791
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• 2023

Risk management is essential for preventing accidents arising from uncertainties in TBM tunnel projects, especially concerning managing the risk of TBM tunnel collapse, which can cause extensive damage from the tunnel face to the ground surface. In addition, prioritizing risks is necessary to allocate resources efficiently within time and cost constraints. Therefore, this study aimed to establish a TBM risk database through case studies of TBM accidents and determine a risk priority for TBM tunnel collapse using the Bayes theorem. The database consisted of 87 cases, dealing with three accidents and five geological sources. Applying the Bayes theorem to the database, it was found that fault zones and weak ground significantly increased the probability of tunnel collapse, while the other sources showed low correlations with collapse. Therefore, the risk priority for TBM tunnel collapse, considering geological sources, is as follows: 1) Fault zone, 2) Weak ground, 3) Mixed ground, 4) High in-situ stress, and 5) Expansive ground. In practice, the derived risk priority can serve as a valuable reference for risk management, enhancing the safety and efficiency of TBM construction. It provides guidance for developing appropriate countermeasure plans and allocating resources effectively to mitigate the risk of TBM tunnel collapse.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.3
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• pp.96-106
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• 2009

Extending the scale of the distributed processing in a single Ethernet cluster is physically restricted by maximum ports per switch. This paper presents an implementation of MPI-based multicluster consisting of multiple Ethernet switches for extending the scale of distributed processing, and a asymptotical analysis for communication overhead through execution-time analysis model. To determine an optimum task partitioning, we analyzed the processing time for various partitioning schemes, and AAP(accumulator array partitioning) scheme was finally chosen to minimize the overall communication overhead. The scope of data partitioned in AAP was modified to fit for incremented nodes, and suitable load balancing algorithm was implemented. We tried to alleviate the communication overhead through exploiting the pipelined broadcast and flat-tree based result gathering, and overlapping of the communication and the computation time. We used the linear pipeline broadcast to reduce the communication overhead in intercluster which is interconnected by a single link. Experimental results shows nearly linear speedup by the proposed parallel distributed GHT implemented on MPI-based Ethernet multicluster with four 100Mbps Ethernet switches and up to 128 nodes of Pentium PC.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.7
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• pp.395-401
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• 2016

Nano-saftey has become an emerging issue recently, because of the broad use of nanomaterials in nano-industries and commercial areas. For a sustainable development in the nano-industry, active studies on nano-safety should be executed, especially on the potential risks in engineered nanomaterials (ENMs). Although acute and chronic assessments of nanomaterials have been extensively studied in many studies, multigenerational studies are very scarce. Overall, multigenerational studies have progressed as two different trends, studying post-generational effects or trans-generation effects. This study intended to suggest further nano-safety studies based on the trends and limitations of current ones. Through a comparative analysis, we investigated peer-reviewed multigenerational studies that used nanomaterials. Thirteen studies on post-generation effects confirmed generational nano-toxicity via several bioassays, such as mortality, fertility, and behavioral assays. Seven studies on trans-generation effects demonstrated nanomaterial pathways to next generations, using imaging techniques. Until now, mechanisms for post-generational nano-toxicity has been rarely proposed. Thus, we propose that complementary studies on such mechanisms are imperative for future studies.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.433-443
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• 2021

Value Engineering(VE) is an organized effort to create the most value through a functional analysis and creation of alternatives. Depending on the VE job plan, a VE Workshop must be performed in a certain place within a certain period of time. A VE Workshop, which is an organized activity that aims to create the best value through functional analysis and creation of alternatives, should be held in a certain place and at a scheduled time according to the VE job plan. In the Pre-Study, VE Study and Post-Study phases of VE, functional assessments, performance evaluations and idea evaluations are driven by variable management techniques and analysis methods, respectively. Generally, VE is executed for about 3 to 5 days in a particular place to create value. However, there are many problems associated with limiting all VE processes to a specific place and schedule. Moreover, in Korea, VE teams are required to finish all VE processes in a limited time because of the short duration of VE workshops, the necessity of which has been overlooked. Therefore, an efficient VE support system is required to resolve the problem of time and space limitations. In this study, a VE support system based on the Mobile environment was developed to support the VE Workshop process. This VE support system enables participants to review design documents, drawing sheets and all VE-related documents using mobile devices. After the Workshop, participants can conveniently rearrange the result(evaluation of function and ideas) at the workshop. Not only can the members of VE team can review the design documents, drawing sheet and all VE-related documents in the step before the workshop, but also the result(evaluation of function and ideas) of the workshop can be easily rearranged in the phase after the workshop under the developed supporting system using mobile devices.

• Cartoon and Animation Studies
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• s.34
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• pp.23-43
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• 2014

The development of the Internet in the 21st century had made a variety of cross-cultural environment so that animations also have evolved with new features to Web-Animation. In Korea, the web-based flash animation leap forward to the animation Utopia in the early 2000's, but did not last long. The web-based animations should attract audience's attention not only with it's minimum streaming capacity but also with showing it's best qualities as well, Therefore, the stimulating narrative strategies were mandatories for web-animation in 2000's. The absence of in-depth research on media, poor revenue structure, and the emergence of mobile games and e-learning industries made the web-animation become just a one-time/one-consumable content. There were no subsequent generation of korean web-animation ever since. In this study, I want to introduce and analyze the american web animation series, (2005) as a new type of web-animation in current digital culture, In particular, I want to discuss how this web animation appeal to the audience with its narrative strategies through using some aspect of the internet culture which's differentiated from traditional media based cultures. This research could suggest diverse narrative strategies for the future web-animation with new vision. Moreover, This also allows to look at latest web-animation trends and its new experiments.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.1
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• pp.43-48
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• 2006

The educational system has been changed owing to Web, which is most actively used on internet and has the characteristics of providing suitable environments for implementing constructivism study theory. WBI(Web Based Instruction), web-mediated teaching form for students at a long distance, has the advantages of possible interact between instructors and learners, offering a great variety of learning materials, and overcome the spatiotemporal restriction. This paper focuces on the construction of learning surroundings where the learner-centered, active learning can be done by design and Implementation of web based instruct system providing a sham examination with an item pool system. The web based Self-directed Learning system for word processor qualifying exams on this paper, can be mentioned as a real item pool that the question is not setting each time by the instructors but can be reused by reference on item pool bank, designed the number of question. It helps the learner Self-directed Learning study with evaluation during the web based instruct process and immediate feedback. It also provides the chance to research some similar using keyword. To sum up, this system can amplify the efficiency of study.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.46-48
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• 2005

이동 컴퓨팅 환경에서 다수의 이동 클라이언트들에게 데이터를 전달할 때는 클라이언트들의 동시 데이터 접근을 지원하는 브로드캐스트 기법을 사용하면 무선 채널 대역폭의 협소함과 클라이언트 측의 에너지 제약과 같은 단점을 해결할 수 있다. 기존 기법들은 클라이언트의 데이터에 대한 접근빈도(access frequencies)와 클라이언트의 에너지 효율(energy efficiency)을 동시에 고려하지 않았다. 따라서 원하는 데이터가 올 때까지 계속해서 채널을 들어야 함으로 인해 에너지 소비를 많이 하거나, 데이터를 얻을 때까지 추가한 많은 양의 정보에 따른 지연이 발생하는 단점이 있다. 본 논문에서는 클라이언트의 에너지 절약을 위한 tuning time을 최소화하고 실제 데이터를 얻을 때까지 소요되는 access time의 효율을 높이기 위해 데이터의 접근빈도와 에너지 효율을 동시에 고려하는 HIDAF: Hybrid Index considering Data Access Frequencies 기법을 제한한다. 제안하는 기법은 트리기반 기법과 해싱기반 기법을 함께 적용하여 구성한 인덱스를 브로드캐스트 주기에 배치한다. HIDAF 기법은 데이터 접근빈도를 고려한 트리기반 인덱스를 배치함으로써 데이터를 얻기 위한 클라이언트들의 평균 access time을 줄일 수 있고, 이러한 인덱스에 해싱기반 기법을 추가함으로써 클라이언트의 에너지 효율을 최소화하는 새로운 브로드캐스팅 기법이다. HIDAF 기법은 브로드캐스트 추기에 데이터의 접근빈도를 고려한 인덱스를 교차로 추가하여 핫 데이터에 대한 클라이언트들의 access time을 줄임으로써 전체 사용자에 대한 평균 access time을 최소화하는 동시에 클라이언트들의 제한된 에너지 소비를 최소화하는데 목적이 있다. 제안기법에 대한 평가는 수학적 분석을 통해 HIDAF 기법과 기존의 브로드캐스트 기법의 성능을 비교 분석한다.하였으나 사료효율은 증진시켰으며, 후자(사양, 사료)와의 상호작용은 나타나지 않았다. 이상의 결과는 거세비육돈에서 1) androgen과 estrogen은 공히 자발적인 사료섭취와 등지방 침적을 억제하고 IGF-I 분비를 증가시키며, 2) 성선스테로이드호르몬의 이 같은 성장에 미치는 효과의 일부는 IGF-I을 통해 매개될 수도 있을을 시사한다. 약 $70 {\~} 90\%$의 phenoxyethanol이 유상에 존재하였다. 또한, 미생물에 대한 항균력도 phenoxyethanol이 수상에 많이 존재할수록 증가하는 경향을 나타내었다. 따라서, 제형 내 oil tomposition을 변화시킴으로써 phenoxyethanol의 사용량을 줄일 수 있을 뿐만 아니라, 피부 투과를 감소시켜 보다 피부 자극이 적은 저자극 방부시스템 개발이 가능하리라 보여 진다. 첨가하여 제조한 curd yoghurt는 저장성과 관능적인 면에서 우수한 상품적 가치가 인정되는 새로운 기능성 신제품의 개발에 기여할 수 있을 것으로 사료되었다. 여자의 경우 0.8이상이 되어서 심혈관계 질환의 위험 범위에 속하는 수준이었다. 삼두근의 두겹 두께는 남녀 각각 $20.2\pm8.58cm,\;22.2\pm4.40mm$으로 남녀간에 유의한 차이는 없었다. 조사대상자의 식습관 상태는 전체 대상자의 $84.4\%$가 대부분이 하루 세끼 식사를 규칙적으로 하고 있었으며 식사속도는 허겁지겁 빨리 섭취하는 경우가 남자는 $31.0\%$, 여자는 $21.4\%$로 나타났고 이들을 제외한 나머지 사람들은 보통 속도 혹은 충분한 시간을 가지고 식사를 하였다. 평소 식사량은 조금 적게 혹은 적당하게 섭취하는 사람이 대부분이었으며 남자가 여자보다는 배부르게 먹는 경 향이 유의적으로 높았다(p<0.05). 식사는 혼자 하는 경우가 남자

• KIPS Transactions on Software and Data Engineering
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• v.4 no.12
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• pp.549-560
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• 2015

There is a wide variety of data quality attributes such as the ones proposed by the ISO/IEC organization and also by many other domestic and international institutions. However, it takes considerable time and costs to apply those criteria and guidelines to real environment. Therefore, it needs to define data quality evaluation attributes which are easily applicable and are not influenced by organizational environment limitations. The purpose of this paper is to derive data quality attributes and order of their priorities based on customer requirements for managing the process systematically and evaluating the data quantitatively. This study identifies the customer cognitive constructs of data quality attributes using the RGT(Repertory Grid Technique) based on a Korean quality standard model (DQC-M). Also the correlation analysis on the identified constructs is conducted, and the evaluation attributes is prioritized and ranked using the AHP. As the results of this paper, the consistent system, the accurate data, the efficient environment, the flexible management, and the continuous improvement are derived at the first level of the data quality evaluation attributes. Also, Control Compliance(13%), Regulatory Compliance(10%), Requirement Completeness(9.6%), Accuracy(8.4%), and Traceability(6.8%) are ranked on the top 5 of the 19 attributes in the second level.

• Journal of Korean Society of Transportation
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• v.22 no.1 s.72
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• pp.43-62
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• 2004

Conventionally the estimation method of the origin-destination Matrix has been developed by implementing the expansion of sampled data obtained from roadside interview and household travel survey. In the survey process, the bigger the sample size is, the higher the level of limitation, due to taking time for an error test for a cost and a time. Estimating the O-D matrix from observed traffic count data has been applied as methods of over-coming this limitation, and a gradient model is known as one of the most popular techniques. However, in case of the gradient model, although it may be capable of minimizing the error between the observed and estimated traffic volumes, a prior O-D matrix structure cannot maintained exactly. That is to say, unwanted changes may be occurred. For this reason, this study adopts a conjugate gradient algorithm to take into account two factors: estimation of the O-D matrix from the conjugate gradient algorithm while reflecting the prior O-D matrix structure maintained. This development of the O-D matrix estimation model is to minimize the error between observed and estimated traffic volumes. This study validates the model using the simple network, and then applies it to a large scale network. There are several findings through the tests. First, as the consequence of consistency, it is apparent that the upper level of this model plays a key role by the internal relationship with lower level. Secondly, as the respect of estimation precision, the estimation error is lied within the tolerance interval. Furthermore, the structure of the estimated O-D matrix has not changed too much, and even still has conserved some attributes.