• Title/Summary/Keyword: Hold time

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A Study on the Actuality of School Safety and the Development of Safety Manual (학교안전교육의 실태분석과 안전교육매뉴얼 개발에 관한 연구)

  • Kim, Tae-Hwan
    • Journal of the Korean Society of Hazard Mitigation
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    • v.5 no.3 s.18
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    • pp.83-88
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    • 2005
  • It is necessary to hold the school safety manual because recently, the safety-related accidents occur frequently in schools. Accidents can occur inside of schools as well as out of schools, and they can be classified with human accidents, traffic accidents, fire accidents, and explosion accidents. Safety-related accidents occurring in the school are dangerous because nobody can predict them. Illegally infringing violence, targeting unspecified and a lot of people, informs the parents and persons concerned to education of danger. School safety manual, never precedented before, describes epoch-making educational methods for students' safety. It describes safety security such as refuging ways at an emergency, the way to recognize danger for elevated safety based on prevention education, the use and practice of checklist for related facilities, and the implements and facilities for school personnels and students. So, the school safety manual is an important guidance for safety education at the level of prevention from various accidents which occur inside the school as well as out of the school. It presents a variety of prompt response after an accident. At the same time, it checks facilities and dangerous factors in schools and facilities for safety, and analyzes special factors based on them. So it will present the status of safety management of existing facilities and implements, the installment of new facilities and implements, and the way to secure safety for use.

Characterizations of Water-dispersed Biocellulose Nanofibers on the Skin Surface (피부 표면에서의 수분산 바이오셀룰로오스 미세섬유의 특성에 대한 연구)

  • Jun, Seung-Hyun;Kim, Seo Yeon;Park, Sun Gyoo;Lee, Cheon Koo;Lee, Seol-Hoon;Kang, Nae-Gyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.1
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    • pp.89-94
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    • 2018
  • In this study, water-dispersed biocellulose nanofibers (TC) were prepared via an oxidation reaction using 2,2,6,6-tetramethyl-1-piperidine-N-oxy radical (TEMPO) as a catalyst. The TC retained their unique structure in water as well as in emulsion. TC adhered to the skin surface while maintaining nanofibrous structures, providing inherent functions of biocellulose, such as high tensile strength and high water-holding capacity. When gelatin gels as model skin were coated with TC, the hardness representing the elasticity was increased by 20% compared to untreated gelatin gel because TC could tightly hold the gelatin structure. When porcine skin was treated with TC and TC-contained O/W emulsion, the initial water contact angles of TC were lower than other materials, and dramatically decreased over time as water penetrated the fibrous structure of the TC film. Characterization of TC on the skin surface offered insight into the function of nanofibers on the skin, which is important for their applications with respect to fiber-cosmetics.

Conceptual Changes of Middle School Students on the Motion of the Moon Using the Cognitive Conflict Instructional Model (인지갈등 수업모형을 적용한 중학생의 달의 운동 개념 변화)

  • Kim, Hee-Soo;Chung, Jung-In;Shim, Ki-Chang
    • Journal of the Korean earth science society
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    • v.25 no.5
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    • pp.348-363
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    • 2004
  • The purpose of this study was to classify types of preconception about the motion of the moon held by middle school students and find out how the lesson applying cognitive conflict instructional model changes their conceptual view of the motion of the moon. A quantitative study was first conducted with 48 ninth graders and then followed by a qualitative study. In the qualitative study, male and female students were organized into groups of five and ten respectively. Students were instructed to observe the motion of the moon about for a month and at the same time were taught via the cognitive conflict instructional model for three class periods. Data were collected from interviews and a questionnaire evaluating the degree of concept development that each student showed. A majority of students were found to hold misconceptions formed from elementary school programs on the motion of the moon. Further, students showed lack of scientific ability to interpret the phenomena of the moon. This study showed that the cognitive conflict instructional model was effective for students to make progress regarding their conceptual views of the motion of the moon. However, it was observed that misconceptions by students may possibly occur when two dimensional figures or miniatures were used.

High resolution flexible e-paper driven by printed OTFT

  • Hu, Tarng-Shiang;Wang, Yi-Kai;Peng, Yu-Rung;Yang, Tsung-Hua;Chiang, Ko-Yu;Lo, Po-Yuan;Chang, Chih-Hao;Hsu, Hsin-Yun;Chou, Chun-Cheng;Hsieh, Yen-Min;Liu, Chueh-Wen;Hu, Jupiter
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.421-427
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    • 2009
  • We successfully fabricated 4.7-inch organic thin film transistors array with $640{\times}480$ pixels on flexible substrate. All the processes were done by photolithography, spin coating and ink-jet printing. The OTFT-Electrophoretic (EP) pixel structure, based on a top gate OTFT, was fabricated. The mobility, ON/OFF ratio, subthreshold swing and threshold voltage of OTFT on flexible substrate are: 0.01 ^2/V-s, 1.3 V/dec, 10E5 and -3.5 V. After laminated the EP media on OTFT array, a panel of 4.7-inch $640{\times}480$ OTFT-EPD was fabricated. All of process temperature in OTFT-EPD is lower than $150^{\circ}C$. The pixel size in our panel is $150{\mu}m{\times}150{\mu}m$, and the aperture ratio is 50 %. The OTFT channel length and width is 20 um and 200um, respectively. We also used OTFT to drive EP media successfully. The operation voltages that are used on the gate bias are -30 V during the row data selection and the gate bias are 0 V during the row data hold time. The data voltages that are used on the source bias are -20 V, 0 V, and 20 V during display media operation.

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Comparative Studies on the Analysis of Pesticide Residues. in Rice, Barley and Wheat (주곡중의 잔류농약분석에 관한 연구)

  • Park Seung Heui
    • Korean journal of applied entomology
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    • v.13 no.4 s.21
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    • pp.235-243
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    • 1974
  • Recenty, the pesticides Pollutions in connection with the maintenance of dietary life are poised as serious sanitary problems. Author have established an appropriate analysis method in this connection and, at the same time, analysed the levels of pesticides residues, such as organochloride pesticides and organic mercurials, contained in main cereals (rice, barley, and wheat) collected throughout the country. Using gas liquid chromatography method, comparative analyses were made of organochloride Pesticides with electron capture detector, and organic mercurials with electron capture detector and the Dithizone Method. As a result, the organic mercurials analysis using gas liquid chromatography is believed to hold out an especially good method for both in terms of its sensitivity and its Practical applications. The summary obtained from these results is as follows; The detectable limit of organochloride pesticides is $5\times10^{-10}$ grams and that of organic mecurials is $5\times10^{-9}$ grams. The detections using the Dithizone Method are difficult. The gas liquid chromatographic analysis of organic mercurials is very simple in its operation and high in its sensitivity, compare with the analysis using the Dithizone Method. Therefore, this analysis is expected to be a good method applicable to the pesticide residues analysis. The levels of pesticide residues contained in samples are very little for tolerance and, therefore, no problem i.: foreseen for eating. The appropriate conditions of gas liquid chromatographic analysis obtained from these results are expected very useful for the date establishing an officially authorized analysis method.

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A Study on the Continuous Speech Recognition for the Automatic Creation of International Phonetics (국제 음소의 자동 생성을 활용한 연속음성인식에 관한 연구)

  • Kim, Suk-Dong;Hong, Seong-Soo;Shin, Chwa-Cheul;Woo, In-Sung;Kang, Heung-Soon
    • Journal of Korea Game Society
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    • v.7 no.2
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    • pp.83-90
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    • 2007
  • One result of the trend towards globalization is an increased number of projects that focus on natural language processing. Automatic speech recognition (ASR) technologies, for example, hold great promise in facilitating global communications and collaborations. Unfortunately, to date, most research projects focus on single widely spoken languages. Therefore, the cost to adapt a particular ASR tool for use with other languages is often prohibitive. This work takes a more general approach. We propose an International Phoneticizing Engine (IPE) that interprets input files supplied in our Phonetic Language Identity (PLI) format to build a dictionary. IPE is language independent and rule based. It operates by decomposing the dictionary creation process into a set of well-defined steps. These steps reduce rule conflicts, allow for rule creation by people without linguistics training, and optimize run-time efficiency. Dictionaries created by the IPE can be used with the speech recognition system. IPE defines an easy-to-use systematic approach that can obtained 92.55% for the recognition rate of Korean speech and 89.93% for English.

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Visualization of Korean Speech Based on the Distance of Acoustic Features (음성특징의 거리에 기반한 한국어 발음의 시각화)

  • Pok, Gou-Chol
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.3
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    • pp.197-205
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    • 2020
  • Korean language has the characteristics that the pronunciation of phoneme units such as vowels and consonants are fixed and the pronunciation associated with a notation does not change, so that foreign learners can approach rather easily Korean language. However, when one pronounces words, phrases, or sentences, the pronunciation changes in a manner of a wide variation and complexity at the boundaries of syllables, and the association of notation and pronunciation does not hold any more. Consequently, it is very difficult for foreign learners to study Korean standard pronunciations. Despite these difficulties, it is believed that systematic analysis of pronunciation errors for Korean words is possible according to the advantageous observations that the relationship between Korean notations and pronunciations can be described as a set of firm rules without exceptions unlike other languages including English. In this paper, we propose a visualization framework which shows the differences between standard pronunciations and erratic ones as quantitative measures on the computer screen. Previous researches only show color representation and 3D graphics of speech properties, or an animated view of changing shapes of lips and mouth cavity. Moreover, the features used in the analysis are only point data such as the average of a speech range. In this study, we propose a method which can directly use the time-series data instead of using summary or distorted data. This was realized by using the deep learning-based technique which combines Self-organizing map, variational autoencoder model, and Markov model, and we achieved a superior performance enhancement compared to the method using the point-based data.

A Strategy To Reduce Network Traffic Using Two-layered Cache Servers for Continuous Media Data on the Wide Area Network (이중 캐쉬 서버를 사용한 실시간 데이터의 좡대역 네트워크 대역폭 감소 정책)

  • Park, Yong-Woon;Beak, Kun-Hyo;Chung, Ki-Dong
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.10
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    • pp.3262-3271
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    • 2000
  • Continuous media objects, due to large volume and real-time consiraints in their delivery,are likely to consume much network andwidth Generally, proxy servers are used to hold the fiequently requested objects so as to reduce the network traffic to the central server but most of them are designed for text and image dae that they do not go well with continuous media data. So, in this paper, we propose a two-layered network cache management policy for continuous media object delivery on the wide area networks. With the proposed cache management scheme,in cach LAN, there exists one LAN cache and each LAN is further devided into a group of sub-LANs, each of which also has its own sub-LAN eache. Further, each object is also partitioned into two parts the front-end and rear-end partition. they can be loaded in the same cache or separately in different network caches according to their access frequencics. By doing so, cache replacement overhead could be educed as compared to the case of the full size daa allocation and replacement , this eventually reduces the backbone network traffic to the origin server.

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A New Mode Changable Asymmetric Full Bridge DC/DC Converter having 0 ~ 100 % Duty Ratio (0 ~ 100 % 시비율을 갖는 새로운 모드 가변형 비대칭 풀 브리지 DC/DC 컨버터)

  • Shin, Yong-Saeng;Roh, Chung-Wook;Hong, Sung-Soo;Han, Sang-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.15 no.2
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    • pp.103-110
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    • 2010
  • In this paper, a new mode changeable asymmetric full bridge dc/dc converter is proposed to solve the freewheeling current problem of the conventional zero voltage switching(ZVS) phase shift full bridge(PSFB) dc/dc converter of low output voltage and high output current applications. The proposed converter is operated as an asymmetric full bridge converter when the duty cycle is less than 50% and active clamp full bridge converter when the duty cycle is greater than 50%. As a result, since its freewheeling current is eliminated, the conduction loss is lower than that of the conventional ZVS PSFB dc/dc converter. Moreover, ZVS of all power switches can be ensured along a wide load ranges and output current ripple is very small. Therefore, high efficiency of the proposed converter can be achieved. Especially since its operation mode is changed to the active clamp full bridge converter during hold up time and can be operated with 50~100% duty ratio, it can produce the stable output voltage along wide input voltage range. The operational principles, theoretical analysis and design considerations are presented. To confirm the operation, validity and features of the proposed converter, experimental results from a 1.2kW($400V_{dc}/12V_{dc}$) prototype are presented.

Dynamic Priority Search Algorithm Of Multi-Agent (멀티에이전트의 동적우선순위 탐색 알고리즘)

  • Jin-Soo Kim
    • The Journal of Engineering Research
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    • v.6 no.2
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    • pp.11-22
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    • 2004
  • A distributed constraint satisfaction problem (distributed CSP) is a constraint satisfaction problem(CSP) in which variables and constraints are distributed among multiple automated agents. ACSP is a problem to find a consistent assignment of values to variables. Even though the definition of a CSP is very simple, a surprisingly wide variety of AI problems can be formalized as CSPs. Similarly, various application problems in DAI (Distributed AI) that are concerned with finding a consistent combination of agent actions can be formalized as distributed CAPs. In recent years, many new backtracking algorithms for solving distributed CSPs have been proposed. But most of all, they have common drawbacks that the algorithm assumes the priority of agents is static. In this thesis, we establish a basic algorithm for solving distributed CSPs called dynamic priority search algorithm that is more efficient than common backtracking algorithms in which the priority order is static. In this algorithm, agents act asynchronously and concurrently based on their local knowledge without any global control, and have a flexible organization, in which the hierarchical order is changed dynamically, while the completeness of the algorithm is guaranteed. And we showed that the dynamic priority search algorithm can solve various problems, such as the distributed 200-queens problem, the distributed graph-coloring problem that common backtracking algorithm fails to solve within a reasonable amount of time. The experimental results on example problems show that this algorithm is by far more efficient than the backtracking algorithm, in which the priority order is static. The priority order represents a hierarchy of agent authority, i.e., the priority of decision-making. Therefore, these results imply that a flexible agent organization, in which the hierarchical order is changed dynamically, actually performs better than an organization in which the hierarchical order is static and rigid. Furthermore, we describe that the agent can be available to hold multiple variables in the searching scheme.

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