• Title/Summary/Keyword: State Of Charge

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A Research on the Real State of Story-telling Mathematics Class of Middle School (스토리텔링을 적용한 중학교 수학 수업에 대한 교사의 인식 및 활용 실태)

  • Yu, EunHwa;Yun, Jong-Gug
    • Communications of Mathematical Education
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    • v.29 no.3
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    • pp.441-463
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    • 2015
  • The big issue of mathematics education in 2009 revised curriculum is to introduce story-telling in math textbook and to aim toward the math that students can learn easily and interestingly. Therefore, this study examine the perception of middle school teachers in working with story-telling, analyze actual utilization of story-telling in class and provide the basic materials for effective practical application. After making questionnaires to check the real conditions of the story-telling and asking math teachers in charge of the first and second graders, this research came to the conclusion as follows. First, the teachers who took part in this research showed positive perception in story-telling textbook the practical use of a variety of materials and the improvement of thinking faculty and creativity. Second, math teachers made use of a variety of storytelling data and especially reflection media in class, but this was limited in introductory part. Mathematic concept was delivered mainly through the activities of exchanging questions and answers between the teachers and students. Third, students showed positive reaction about story-telling class on the whole. For example, they understood the concept easily and they could apply it in real life. However, story-telling failed to bring the attention and interest of math itself. Therefore, teachers' ability is needed in the way that math knowledge and concept should be formed and expressed interestingly.

Effect of Thermal Management of Lithium-Ion Battery on Driving Range of Electric Vehicle (리튬이온 배터리의 열관리가 전기자동차 주행거리에 미치는 영향)

  • Park, Chul-Eun;Yoo, Se-Woong;Jeong, Young-Hwan;Kim, Kibum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.22-28
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    • 2017
  • The performance of lithium ion batteries used in electric vehicles (EV) varies greatly depending on the battery temperature. In this paper, the finite difference method was used to evaluate the temperature change, state of charge (SOC), internal resistance, and voltage change of the battery due to heat generation in the battery. The simulation model was linked with AMESim to calculate the driving range of an EV traveling in New European Driving Cycle (NEDC) mode. As the temperature dropped below $25^{\circ}C$, the internal resistance of the battery increased, which increased the amount of heat generated and decreased the driving range of EV. At battery temperatures above $25^{\circ}C$, the driving range was also decreased due to reduced SOC that deteriorated the battery performance. The battery showed optimal performance and the driving range was maximized at $25^{\circ}C$. When battery temperatures of $-20^{\circ}C$ and $45^{\circ}C$, the driving range of EV decreased by 33% and 1.8%, respectively. Maintaining the optimum battery temperature requires heating the battery at low temperature and cooling it down at high temperature through efficient battery thermal management. Approximately 500 W of heat should be supplied to the battery when the ambient temperature is $-20^{\circ}C$, while 250 W of heat should be removed for the battery to be maintained at $25^{\circ}C$.

Measurement of Spatiotemporal Distribution for the Density of Excited Xe Atoms in the 1s5 in Accordance with Various ITO-shapes in Ac-PDP (교류형 플라즈마 평판 표시장치(AC-PDP)에서 ITO 전극 구조에 따른 Xe 여기종의 시공간 밀도 분포 연구)

  • Cho, S.H.;Hong, Y.J.;Son, C.G.;Han, Y.G.;Jeong, Y.H.;Gwon, G.C.;Hong, B.H.;Cho, G.S.;Choi, E.H.
    • Journal of the Korean Vacuum Society
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    • v.18 no.1
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    • pp.54-59
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    • 2009
  • We have measured the spatiotemporal behavior for the density of excited Xe atoms in the $1s_5$ metastable states by laser absorption spectroscopy in accordance with various shapes of ITO electrode. The maximum density of excited Xe atoms in the Is5 state in a discharge cell for fish-boned, T-shaped and squared ITO electrodes has been measured to be $3.01{\times}10^{13}\;cm^{-3}$, $2.66{\times}10^{13}\;cm^{-3}$ and $2.06{\times}10^{13}\;cm^{-3}$, respectively. Throughout this experiment, we could understand the influence of the shapes of ITO electrode of micro discharge cell on the high efficiency of AC-PDPs.

Competitive Adsorption of Cd and Cu on Surface of Humic Acid Extracted from Peat (피트에서 추출한 부식산 표면에 대한 카드뮴과 구리의 경쟁 흡착)

  • Lim, Soo-Kil;Chung, Chang-Yoon;Ok, Yong-Sik;Kim, Jeong-Gyu
    • Korean Journal of Soil Science and Fertilizer
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    • v.35 no.6
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    • pp.344-351
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    • 2002
  • Chemical speciation and transport of heavy metals in soil environment could be controlled by humic acid. In order to understand the mechanism on competitive adsorption of Cd and Cu on the surface of humic acid extracted from peat, the charge development of humic acid were investigate through a batch adsorption experiment with a series of different background electrolytes levels. The competitive adsorption of Cd and Cu to the humic acid were estimated according to the model using the proton binding constant obtained from the above batch test. The affinity of Cu to the carboxyl group on the humic acid was higher than that of Cd, but the affinity to the phenolic group was lower than to the carboxyl group. It seems that the amount of adsorbed Cd and Cu could be estimated using the proton binding constant obtained from a solution with single background ion. However, it is difficult to interpret the competitive adsorption of Cd and Cu with the constant for single background ion.

A Study on the Documentation Method of Intangible Cultural Heritage and Training Center (무형문화유산 기록화와 전수교육관에 대한 연구)

  • Kim, Ji-hee;Lee, Young-hak
    • The Korean Journal of Archival Studies
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    • no.56
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    • pp.147-182
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    • 2018
  • Intangible cultural heritage is formless. It's of importance to preserve heritage in line with society drastically being transformed. It's passed down by human being. It is, on the other hand, impossible to preserve intangible cultural heritage solely based on memory, for it's changed in succession. Thus, it be archived to pass down. This study investigated on the state of affair related with Intangible cultural heritage documentations, examined the shortages thereupon. Furthermore, Training center should be in charge of documentation for a solution. This will provide an opportunity to overcome the limitations attributed to the top-down documentation system by central administrative organ, to open up the possibility of viewpoint of different successors, organizations. In addition to that, Intangible cultural heritage documents should be of different aspects of community history. Features of Intangible cultural heritages, which are convergent to the Regionality, tendency of variation, transmission, can be magnified when documentating. Finally, Training center is going to play a major role being vitalised. The record management of intangible cultural heritage, institutions and policies about Intangible cultural heritage have been highly complicated since National Intangible Heritage Center opened and the law on Intangible cultural heritage enacted with its recognition attracted. Therewith this study wishes to see a cornerstone of records on intangible cultural heritage by laying stress on training center in which educations and pass-down of intangible cultural heritage are lively achieved.

식음료 서비스 산업의 과학적 경영 관리에 관한 연구

  • 김동승;이상정
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.8
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    • pp.21-33
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    • 1997
  • This study reviews the scientific management theories and discusses those theories within the food service industry. By providing the principles and the practical implications of the theories on the food service industry, this study tries to identify their philosophies and usefulness to the industry so that the managers in the industry use them in their dylmanic operations. In the fastly changing modern globalized world, we now face a situation where it's becoming more and more difficult to mange a restaurant business. In order to build a food industry business that can maintain a continuous development in today's business environment, one will have to apply the professional management theory in a cost-reduce strategy. It is more important though to have managers, organization members, in short, any person who can work to be motivated in accomplishing these two major issues-income increase and cost reduction. In this erawhere it's getting so difficult for researches on possible strategies for these business managers to overcome their difficulties. It is for certain that in the upcoming second millenium the travel and tourism industry will be one of the world's biggest industry worldwide. Korea's hotel industry has developed since the 1988 Seoul Olympic Games and has shown great amount of competition within the same business. Thus managers have become acquainted with the "know-how" strategy and the practical and scientific managemnet theories were introduced. This helped not only to increase income but also to maximize profit. However, rather than concentration on the "Hard-ware" aspect "Soft-ware" related professional management strategies were developed along with professionalism and human service were emphazied. As such, the actual cost of food and beverages are for the hotel industry business managers the biggest shortterm expense item. Due to the natural state of food items, there is a great chance of "Loss" in preservance, and this is the reason it is complicated to effectively maintain food. As a consequence, very often, the failure to managea hotel or restaurant depends on the capability of the food and beverage preservance mangement: on how they are able to manage effectively the original price of food and beverage. Finally, the main problem of the original price management of food and beverage in Korean hotels are: a) No fixation of set price b) The difficulty to calculate the price difference between a set price and an original price. c) Lack of professinalism in managing the food and beverage original price. d) Lack of perception of the highest ranking management personnels. So as to reform these matters it is necessary to : a) Reform on the management accounting system b) Emphasize to the people in charge on the idea of original price management c) Reinforce original price mangement prevention and assurance of indepedent inspection rights d) Reat manpower

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A Study on Estimation of Road and Transportation Facility Improvement Direction Using Random Forest (랜덤 포레스트를 활용한 도로 및 교통시설 개선방향 추정 연구)

  • Hwang, Jae-seong;Kim, Do-kyeong;Kim, Nam-sun;Lee, Choul-ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.6
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    • pp.37-46
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    • 2021
  • Government agencies, such as police and local governments, strive to prevent traffic hazards and create a comfortable road environment by pormoting transportation and road facilities. To this end, roads and transportation facilities are enhanced and adjusted, and improvement projects in areas with frequent traffic accidents are carried out. Usually, improvement projects in areas with frequent traffic accidents vary by projects and region. Moreover, these projects are carried out under the supervision of a person in charge and related parties. Hence, civil complaints and subjectivity are reflected in deriving priorities for the improvement projects, limiting the efficiency of the project. To this end, a study was conducted to estimate the direction of improvement of the project target site. This study comprehensively considered road, traffic, and accident conditions of representative projects with high effectiveness in handling traffic accidents. The results of the study state that the accuracy of estimating the improvement project was around 88%. In addition, the study found that there was a strong relationship between traffic volume, accident rate, and accident severity in estimating the improvement direction.

A Study on Counting Measurement of Cultural Infrastructure Visitors: Focused on the Wireless Signal-Based Measurement (무선신호기반 측정방식을 활용한 문화기반시설 이용자 현황 측정에 관한 연구)

  • Kim, Ji-Hak;Park, Geun-Hwa
    • Korean Association of Arts Management
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    • no.59
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    • pp.73-99
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    • 2021
  • Free admission policies have been gradually extended for the public to use cultural facilities free of charge, which lowered the barriers to use those facilities and has a great effect on increasing visitor demands. However, the annual number of visitors which is open to the public isn't quite accurate and varies from institution to institution, which means just a head count. Especially people counter overestimates the number of visitors because it counts visitors in duplicate. Therefore, the purpose of this study is to prepare effective way of grasping the number of visitors using cultural infrastructure. First, comparable number of visitors should be measured by defining the notion of visitor clearly, which has been measured vaguely. Secondly, the problem of duplicate count, which is considered the most problematic, should be solved. Thirdly, the various analysis of visitor behavior should be conducted to provide a high-quality service. To work out the problems above, new measurement will be presented here. This study suggests a state-of-the-art wireless signal-based measurement that could eliminate the duplicate data by collecting MAC address -smart device's distinct signal value. And it also could analyze diverse visitor behaviors by understanding a flow of visitor traffic, duration of stay and revisitation. I would like to examine the possibility and effectiveness of this new measurement by testing it.

A Study on the Problems and New Strategy of the Development Policy for Under-developed Region: Focused on the Awareness of the Officials in Charge of Regional Development (낙후지역 개발정책의 문제점과 개선방향에 관한 연구: 지역개발담당 공무원의 인식도를 중심으로)

  • Lee, Byeong-Woo;Kim, Nam-Jung;Lee, Myoung-Gu
    • Land and Housing Review
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    • v.3 no.4
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    • pp.307-314
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    • 2012
  • This paper examines the characteristics and status of the major development policies for under-developed region by ministries and studies how the awareness or perspective of public officials on such policies impact the policy environment. This paper aims to redefine the goal and strategy of regional development policy so that it can effectively contribute to enhancing the quality of life of residents and improving competitiveness of the region. The problems and improvement direction found out through a documentational and practical research on the development policy for underdeveloped region can be summarized as follows: Firstly, more streamlined and integrated policies which are currently fragmented being implemented by different ministries are needed to enhance the effectiveness of policy execution. Secondly, improvements on the process of securing government funding and operating systems are needed to guarantee the rational standard of providing state subvention, the expansion of comprehensive subsidy and the independence of policy execution. Thirdly, amendments on the policy measures are needed to support the development and execution of the customized projects, strengthen cooperation among those projects by establishing a system for effective regional development project.

ARPES Study of Quasi-Two Dimensional CDW System CeTe2 (준이차원 전하밀도파 CeTe2의 각분해 광전자 분광 연구)

  • Kim, D.H.;Lee, H.J.;Kang, J.S.;Kim, H.D.;Min, B.H.;Kwon, Y.S.;Kim, J.W.;Min, B.I.
    • Journal of the Korean Magnetics Society
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    • v.20 no.5
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    • pp.173-177
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    • 2010
  • The electronic structure of charge-density-wave (CDW) system $CeTe_2$ has been investigated by using angle-resolved photoemission spectroscopy (ARPES). The clearly dispersive band structures are observed in the measured ARPES spectra, indicating the good quality of the single-crystalline sample employed in this study. The four-fold symmetric patterns are observed in the constant energy (CE) mappings, indicating the $2{\times}2$ lattice deformation in the Te(1) sheets. The observed CE images are similar to those of $LaTe_2$, suggesting that Ce 4f states have the minor contribution to the CDW formation in $CeTe_2$. This study reveals that the carriers near the Fermi level should have mainly the Te(1) 5p and Ce 5d character, that the Te(1) 5p bands contribute to the CDW formation, and that the Ce 5d bands cross the Fermi level even in the CDW state.