• ALGAE
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• 제26권1호
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• pp.61-71
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• 2011

Thirty populations of Chondrus crispus Stackhouse from Nova Scotia were collected during the years 1993 to 2011. Taken from estuaries, wave exposed open coasts, high intertidal rock pools and shallow subtidal habitats, the populations were evaluated for relative abundance of tetrasporophytic and gametophytic life history phases. Over 2,800 thalli were characterized using the resorcinol-acetal test to distinguish the kappa- and lambda-carrageenan containing fronds of gametophytes and tetrasporophytes, respectively. These populations had $77{\pm}5%$ gametophytes (mean ${\pm}95%$ confidence interval), with most populations having gametophyte : sporophyte ratios ranging from 2 : 1 to 9 : 1. No population had a dominance of tetrasporophytes, although two populations had 1 : 1 ratios. A meta-analysis of our data along with previously published accounts showed no significant changes in gametophyte dominance with respect to hypothesized gradients of wave exposure, salinity, or water depth. Significant changes occurred in ratios at five sites where replicate sampling occurred in different years. We conclude that C. crispus in Maritime Canada has a natural ratio of 3 : 1 or greater in stable conditions, and that lower ratios represent recovery from disturbance in which bare substratum is created that is subsequently colonized by carpospores from remaining gametophytic thalli.

• 대한산업공학회지
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• 제34권4호
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• pp.433-444
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• 2008

With development of RFID technology, medicine and national defense as well as logistics and distribution industries have tried to adopt RFID system. Small projects as well as large national projects have planned to adopt the new technology. However, a lot of companies that have promoted a RFID-based project have confronted many problems due to a lack of information about demonstration projects and absence of systematic guideline. Therefore, it's urgent to develop a practical and useful guideline for companies that have considered to adopt the RFID system. In this paper, a practical framework to adopt RFID system is suggested by five phases : establishment of project plan, analysis of objectives, selection of equipments, development/installation, and operation/post management phases. Besides, a detail method by each stages is also given. A systematic RFID system adoption procedure has been defined through an analysis on demonstrated projects and interview with an expert and the adoption method by stage has been suggested. The purpose of this paper is to minimize the entry barriers by suggesting a practical RFID adoption procedure.

• Ocean and Polar Research
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• 제23권2호
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• pp.97-107
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• 2001

The Sejong Formation of Late Paleocene to Eocene is a lower volcaniclastic sequence unconformably overlain by upper volcanic sequence, and distributed along the southern and southeastern cliffs of the Barton Peninsula. The Sejong Formation is divided into five sedimentary facies; disorganized matrix-supported conglomerate (Facies A), disorganized clast-supported conglomerate (Facies B), stratified clast-supported conglomerate (Facies C), thin-bedded sandstone (Facies D), and lapilli tuff (Facies E), based on sedimentary textures, primary sedimentary structures and bed geometries. Individual sedimentary facies is characterized by distinct sedimentary process such as gravel-bearing mudflows or muddy debris flows (Facies A), cohesionless debris flows (Facies B),unconfined or poorly confined hyperconcentrated flood flows and sheet floods (Facies C), subordinate streamflows (Facies D), and pyroclastic flows (Facies E). Deposition of the Sejong Formation was closely related to volcanic activity which occurred around the sedimentary basin. Four different phases of sediment filling were identified from constituting sedimentary facies. Thick conglomerate and sandstone were deposited during inter-eruptive phases (stages 1, 3 and 4), whereas lapilli tuff was formed by pyroclastic flows during active volcanism (stage 2). These records indicate that active volcanism occurred around the Barton Peninsula during Late Paleocene to Eocene.

• 인터넷정보학회논문지
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• 제15권4호
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• pp.135-140
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• 2014

본 논문에서는 모바일 앱을 위한 개발과정 모델을 제안하였다. 이 개발과정에는 요구분석, 아키텍쳐설계, 네비게이션설계, 페이지 설계 구현과 테스팅 단계를 포함한 다섯가지 개발단계가 있다. 그리고 다이어그램이 있는 설계방법도 제안하였다. 프로그램개발자는 기능적 요구사항과 설계앱을 정의하는데 본 논문에서 제안한 개발방법을 이용할수 있다. 또한 개발시간과 노력을 줄일 수도 있다. 본 논문에서는 모바일 앱 개발에 이 방법을 적용하였고, 개발과정을 수행한 결과물로 다이어그램을 제시하였다.

• Earthquakes and Structures
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• 제10권6호
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• pp.1429-1449
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• 2016

The effect of porosity on bending and free vibration behavior of simply supported functionally graded plate reposed on the Winkler-Pasternak foundation is investigated analytically in the present paper. The modified rule of mixture covering porosity phases is used to describe and approximate material properties of the FGM plates with porosity phases. The effect due to transverse shear is included by using a new refined shear deformation theory. The number of unknown functions involved in the present theory is only four as against five or more in case of other shear deformation theories. The Poisson ratio is held constant. Based on the sinusoidal shear deformation theory, the position of neutral surface is determined and the equation of motion for FG rectangular plates resting on elastic foundation based on neutral surface is obtained through the minimum total potential energy and Hamilton's principle. The convergence of the method is demonstrated and to validate the results, comparisons are made with the available solutions for both isotropic and functionally graded material (FGM). The effect of porosity volume fraction on Al/Al2O3 and Ti-6Al-4V/Aluminum oxide plates are presented in graphical forms. The roles played by the constituent volume fraction index, the foundation stiffness parameters and the geometry of the plate is also studied.

• 한국운동역학회지
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• 제17권1호
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• pp.185-190
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• 2007

The purpose of this study was to investigate the effects that breathing, thoracic and abdominal, had on the smoothness while performing ballet pour de bra. Five skilled ballet dancers(age: $24{\pm}1$, height: $163.4{\pm}2.88$, weight: $44.4{\pm}1.34$) with experience of over 10 years participated in this study. Each participant performed the ballet movement three times with abdominal respiration and with thoracic respiration. The kinematic data was recorded at 60 Hz with three digital cameras (Sony VX-2100). The pour de bra movement consists of two phases, up and down. The up phase is defined as the movement from the en bas through the en avant to the en haut. The down phase is defined as the movement from the en haut through the $\grave{a}$ la seconde to the en bas. During these two phases the Jerk Cost (JC) factor was calculated for the shoulder, elbow and wrist to quantify the smoothness. The group who performed the movement while abdominal respiration had a lower JC factor and so it was concluded that while abdominal respiration the smoothness of the movement was increased as opposed to the thoracic respiration.

• Journal of Power Electronics
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• 제18권1호
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• pp.56-69
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• 2018

In this paper, an improved Space Vector Modulation (SVM) based fault tolerant operation on a nine-level Cascaded H-Bridge (CHB) inverter with an additional backup circuit is proposed. Any type of fault in a power converter may result in a power interruption and productivity loss. Three different faults on H-bridge modules in all three phases based on the SVM approach are investigated with diagrams. Any fault in an inverter phase creates an unbalanced output voltage, which can lead to instability in the system. An additional auxiliary unit is connected in series to the three phase cascaded H-bridge circuit. With the help of this and the redundant switching states in SVM, the CHB inverter produces a balanced output with low harmonic distortion. This ensures high DC bus utilization under numerous fault conditions in three phases, which improves the system reliability. Simulation results are presented on three phase nine-level inverter with the automatic fault detection algorithm in the MATLAB/SIMULINK software tool, and experimental results are presented with DSP on five-level inverter to validate the practicality of the proposed SVM fault tolerance strategy on a CHB inverter with an auxiliary circuit.

• Educational Technology International
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• 제17권1호
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• pp.1-37
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• 2016

The purpose of this study was to develop a MOOC design model that would improve the current practice of MOOC development in Korea by specifying easy-to-use course development procedures and guiding strategies. Following Richey and Klein (2007)'s conceptual model development procedure, the first step was to perform critical review of relevant literature and observe typical MOOC development processes. As a result, the initial model was developed. The second step was to conduct the expert review with five educational technology and MOOC researchers to secure the internal validity of the model. Based on the experts' suggestions, the model was revised and once again reviewed by the same experts. This process resulted in the development of the 2^nd version of model. The third step was to carry out external validation research in order to test the effectiveness, efficiency, and usability of the model. A basic model may be confirmed or corrected based on examination of its results. Consequently, the model was elaborated as the final model. In the final model, 6 procedural phases and 9 specific steps were included. The six procedural phases are: Analysis (1st Iteration), Design, Development (Course Development), Implementation, Evaluation, and Analysis (2nd Iteration), a slight variation of ADDIE model. The specific steps include: 1) Goal Setting, 2) Environment Analysis, 3) Content Design, 4) Style Design, 5) Course Development, 6) Implementation Plan, 7) Course Implementation, 8) Summative Evaluation, and 9) Need Reflection. The study concluded with suggestions for further research and application of the MOOC design model.

• Educational Technology International
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• 제6권1호
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• pp.103-119
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• 2005

This study investigated to designand implement web-based collaborative learning system Co-Net and map out students' learning procedure using the system, based upon Student Team Achievement Division (STAD Slavin, 1990, 1996). There are technical process and instructional considerations to be made during the design process. The former are those that concern equipment requirements and specifications and include Ease of Use, Speed of Access, and Flexibility. On the other hand, instructional considerationsare concerned with the delivery and access of instructional materials and their outcomes on learners. They are cooperative interactions within groups and group heterogeneity, learner control, group incentives, individual accountability, equal opportunity for earning high scores and contributing to group effort, task specialization, and competition among groups. A web site for a virtual learning environment designed and built by the authors and known as Co-Net is then explained along with the whole process learners inside the environment. The main page of Co-Net consists of 15 menus to implement cooperative learning process. The cooperative learning activities using 15 menus are composed of six phases (1) preparation of the new knowledge (2) presentation of the new knowledge (3) knowledge assimilation and application (4) team and individual evaluation (5) team and individual recognition Throughout the five phases, the appropriate use of cooperative learning techniques has been shown to have both academic and social benefits to learners.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제26권4호
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• pp.257-275
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• 2023

본 연구는 초등학교 5학년 학생들을 대상으로 수학적 논증을 강조한 수업을 설계 및 구현하여 수업의 실제를 분석하였다. 문헌 연구를 통해 수학적 논증을 강조한 수업을 1) 패턴 주목하기, 2) 추측 분명히 나타내기, 3) 시각적 모델로 표현하기, 4) 표현에 근거한 논증하기, 5) 비교 및 대조하기 5단계로 구성한 다음, 연속된 홀수의 합은 제곱수임을 주제로 수업을 설계하였다. 그리고 실제 수업 과정에서 수학적 논증을 강조한 수업이 어떻게 구현되는지 수업의 흐름을 단계별로 분석하였다. 본 연구의 결과를 바탕으로 초등학교에서 수학적 논증을 강조한 수업의 시사점을 논의하였다.