• Title/Summary/Keyword: 벨트

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X-ray Powder Diffraction Structural Phase-transition Study of $(Na_{0.7}Sr_{0.3})(Ti_{0.3}Nb_{0.7})O_3$using the Rietveld Method of Analysis (분말 X-선 회절의 리트벨트 해석법을 이용한 $(Na_{0.7}Sr_{0.3})(Ti_{0.3}Nb_{0.7})O_3$계에서의 구조 상전이 특성연구)

  • Jeong, Hun-Taek;Kim, Ho-Gi
    • Korean Journal of Materials Research
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    • v.5 no.6
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    • pp.748-753
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    • 1995
  • Solid solution of NaNb $O_3$70 mol% and SrTi $O_3$30 mol% was single phase. A broad dielectric peak was found at about l00K. Crystal structure was analysed at room temperature and 12K using Rietveld analysis. The unit cell was assigned to have a a doubled lattice parameter of simple perovskite sturcture at room temperatue, the structure was orthorombic with space group Pmmn. At 12K, the structure was also orthorombic with space group Pnma. This structure change with temperature was due to the distortion of oxygen octahedron. This distortion of oxygen octahedron was made by the decrease of (Ti, Nb)-O bounds length with no variation of (Ti, Nb)-O-(Ti, Nb) bound angle. Therefore the broad dielectirc peak about l00K was attributed to the structural change casued by oxygen octahedron distortion.

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The Effect of SNAGs and Biofeedback Training on the Integrative Propriocepcion and Function of the Patients with Cervical Disorder (목의 기능장애 환자들에게 SNAGs기법과 바이오피드백 훈련이 통합적 고유수용성 감각과 목의 기능에 미치는 효과)

  • Lee, Eun Sang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.284-290
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    • 2020
  • This study was undertaken to determine the effects of SNAGs (sustained natural apophyseal glides) and visual convergence biofeedback on the proprioception and neck disability of patients with chronic neck dysfunction. A total of 31 patients with neck dysfunction were assigned to either SNAGs (n = 16) or biofeedback (n = 15). The groups were assessed for proprioception and neck disability, before and after the intervention. The SNAGs were performed using belt with flexion, extension and right-left rotation, whereas biofeedback training included visual feedback training with deep neck flexor. Intervention was implemented for 20 minutes, twice a week for 4 weeks. Biofeedback training a showed significant effect on the joint position sense (left and right rotation) as compared to the SNAGs group (p< 0.05), whereas neck disability index was significantly effective for SNAGs (p< 0.05). Ed. Notes: The previous statement lacked clarity. I have suggested the edit as per my understanding. Please review and revise appropriately, if required. Therefore, the SNAGs technique is effective for neck function, and biofeedback training is a positive intervention method for enhancing the proprioceptive sensation. In future studies on patients with neck pain, it may be possible to select an intervention method based on the characteristics of the disease.

Synthesis and Characterization of high energy density cathode materials for Lithium secondary batteries (리튬이온전지용 고밀도 양극 활물질의 합성 및 특성 연구)

  • Kwon, Yong-Jin;Ahn, Yong-Kwan;Jee, Mi-Jung;Choi, Byung-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.259-259
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    • 2007
  • 층상구조의 전이금속 산화물($LiMO_2$, M=Co, Ni, Mn)은 리튬이차전지용 양극재료로 활발한 연구가 진행되고 있다. 차세대 리튬이차전지 시스템의 개발 및 고성능화를 위해서는 전지의 용량을 결정하는 핵심 부품인 양극재료의 고용량화 및 고안정화는 필수 불가결하다. 따라서 본 연구에서는 상업적으로 큰 장점이 있는 고상반응 공정을 이용하여 리튬이차전지용 양극소재를 제조하고, 소재의 전기화학적, 구조적인 특성을 평가하였으며, 다음과 같은 주제를 가지고 연구를 진행하였다. $LiCoO_2$ 양극재료는 리튬이온전지로 널리 사용되고 있다. 높은 에너지 밀도의 리튬이온전지를 얻기 위해서는 $LiCoO_2$ 양극재료가 고용량화 및 고밀도화를 가져야 한다. 여기서 $LiCoO_2$ 분말이 irregular particle morphology를 가지면 tap density가 $2.2-2.4gcm^{-3}$로 에너지 밀도가 낮으나, 구형 $LiCoO_2$의 정극재료는 tap density가 $2.6-2.8gcm^{-3}$로 상대적으로 energy density가 높아지는 효과가 있다. 구형 $LiCoO_2$ 양극재료를 합성하기 위해서는 chelating agent를 이용한 "controlled crystallization" 침전법을 사용하여 합성한 구형 코발트 수화물을 사용하고 있다. "controlled crystallization" 침전법에서 사용되는 chelating agent로는 주로 ammonia가 이용되고 있다. 본 연구에서는 chelating agent로 ethylene diamine을 사용하여 sodium hydroxides를 precipitation으로 침전 반응하여 구형 코발트 수화물을 합성하였다. 상기 방법으로 합성된 코발트 수화물과 리튬 수화물($LiOH{\cdot}H_2O$-고순도화학(高殉道化學))을 사용하여 고상법을 통하여 $LiCoO_2$를 합성하였다. 제조된 분말의 결정구조와 전기화학적 특성분석은 X-선 회절분석 및 리트벨트 구조정산, 그리고 충/방전 싸이클링을 수행하였으며, 분말의 미세구조 변화를 SEM을 이용하여 분석하였다.

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Evaluation of Biological Critical Control Points Using Escherichia coli Genotyping (Escherichia coli Genotype을 이용한 생물학적 Critical Control Point의 적합성 평가)

  • Kim, Hak-Jae;Hahn, Tae-Wook;Juong, Ji-Hun;Bahk, Gyung-Jin;Hong, Chong-Hae
    • Food Science of Animal Resources
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    • v.29 no.6
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    • pp.695-701
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    • 2009
  • This study was performed to evaluate the effectiveness of biological critical control points using the genetic profile of Escherichia coli isolates from pork cutting plants. Samples were collected from carcasses, equipment (knife, table, glove, transport belt, boning and skinning machine), the environment (wall and floor), and meat cuts during the cutting process from two plants. Pulsed-field gel electrophoresis (PFGE) was used to characterize the E. coli isolates. An identical genotype was detected from the carcasses, equipment, environment, and final meat cuts, and showed that the incoming carcasses, which were contaminated during transportation from slaughterhouses, were a major source of E. coli that was spread throughout processing. Also, consistent cross-contamination due to improper cleaning and disinfection procedures was another possibility. As a result, incoming carcasses and cleaning procedures should be considered critical control points in pork cutting plants, since a heating step is not used to inactivate microorganisms. Furthermore, the high rate (59.6%) of E. coli isolation indicates E. coli can be a good indicator in livestock processing plants even though it has genetic diversity.

A Study of "Missed Encounter" between American Culture and Latin Culture and the Border Theory (미국문화와 라틴문화의 '어긋난 조우'와 탈경계성 연구: 테오도르 루스벨트와 호세 마르티, 그리고 1898년 미서 전쟁을 중심으로)

  • Shin, Myoung Ash
    • Cross-Cultural Studies
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    • v.25
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    • pp.55-85
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    • 2011
  • Many States such as Arizona, Texas, New Mexico, Colorado, California, New Mexico, Florida were obtained either from Spanish Empire or from Mexico. In 1848 due to the Guadalupe-Hidalgo treaty America could obtain half of the original territory of Mexico. American identity cannot be understood without the history of American expansionism further consolidated by the Spanish-American War in 1898, which brought other ex-Spanish colonies such as Guam, Puerto Rico, the Philippines to the US. The US's interest in these territories dates back to the Monroe doctrine in 1823 when Monroe "declared the Americas off-limits to any new European colonization." America justifies their expansion based on the notion of Manifest Destiny which was created by O'Sullivan at the hight of American fever to annex Texas to US. The intent of this paper is to study how Anglo-Saxon and Latin Culture clashed against each other especially right before and after the Spanish-American War. In this study the American hero, Theodore Roosevelt and Latin American hero, $Jos{\acute{e}}$ Martí will be compared, though they did not meet each other during the Spanish-American war due to Marti's early death in 1895 at the battle for the Cuba Libre. Their comparison is significant in that the former represents the American expansionist spirit and the latter the spirit of Anti-imperialism and Anti-Anglocentrism. Along with the concept of Manifest Destiny of America, 'American exceptionalism' is also mentioned which motivates U.S. to expand further even after the Spanish-American war in the form of 'informal imperialism' characterized by 'gunboat politics'of the US. These discussions will draw attention to how recent theorists such as Bryce Traister criticizes the Border Theory represented by $Jos{\acute{e}}$ David Saldívar. Here the Border Theory is criticized to repeat the discourse of the globalized capitalism which prefers the weak state and the transnational aspects by focusing on the in-betweenness of the border. In the end the paper will focus on how the Border theory as represented by Saldivar is political enough and sets up a resistant example against American expansionism of today in its focus on the call for pan-American and pluri-versal subjectivity of the borderlands. This point will be supported by a discussion of how Saldivar's view is confirmed by Walter Mignolo who advocates the "bottom up" resistance of the indigenous people of Chiapas and other social forums such as World Social Forum and the Social Forum of the Americas derived from the Zapatistas' movement whose motto is "A World in which many world co-exist."

A Study on Vibration & Noise Reduction of Fast Back Feeding Device for Manufacturing Process (제조공정용 Fast Back 이송장치 진동·소음 저감에 관한 연구)

  • Han, Doo-Hee;Lee, Seung-Hun;Son, Yung-Deug
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.642-648
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    • 2019
  • This paper presents a fast back-type transfer device for snack food processing that uses the inertia of transferred material. A conventional conveying system is a drive system that uses a belt conveyor and mechanical crank, which generate noise and vibration and cause environmental pollution. Vibration and noise are reduced in the proposed fast back feeding device by using a counterweight. The crank drive unit was replaced with a linear servomotor, and an equilibrium device was designed to balance the force due to acceleration. This makes it is possible to adjust the forward and backward speed and acceleration through PLC control. A vibration damper device offsets the vibration force of the periodic shock form. The main cause of the vibration was identified through vibration analysis, and reduction measures were established. We verified the effectiveness of the vibration by making a prototype and performing about 10 vibration tests. Because no mechanical transducer is needed, energy loss, noise, and vibration do not occur, and the operating speed is not limited.

Research of Usability Test on Disabled Welfare Vehicle for Guardians and Passengers of Disabled People (장애인 보호자 및 탑승자를 대상으로 한 장애인 복지차량 사용성 평가 연구)

  • Rhee, Kun Min;Kim, Dong Ok
    • 재활복지
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    • v.20 no.3
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    • pp.141-161
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    • 2016
  • This research is to anticipate problems of Ray's disabled experiment welfare vehicles for 17 drivers with disability, improving them. In addition it is to provide the criteria for ergonomic design based on perspective of drivers with disability by investigating 18 items of usability test. The results are as follows. First, satisfaction degree of Ray, disabled experiment welfare vehicle, was shown to be 3.88 which is higher than normal vehicles whose degree is 3.20. This showed that the disabled experiment welfare vehicle is the one with much improvement. Second, so as to develop a welfare vehicle it needs to take into account some factors including rear slope, wheelchair locker, seat belt, safety grip, and high roof. Third, in case of rear slope, high roof and width of manual or automatic wheel chairs should be considered and motor-operated device should also be taken into account for safety lockers, which make a wheelchair firmly fixed. Moreover, motor-operated seat and rear slope can be chosen for either of the disabled and the elderly.

China's 'One Belt and One Road' Initiative and Strategy: Development and Limitations (중국의 '일대일로'(一帶一路) 구상과 전략: 발전과 한계)

  • Heur, Heung-Ho
    • The Journal of the Korea Contents Association
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    • v.19 no.7
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    • pp.335-347
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    • 2019
  • China's 'One Belt and One Load' initiative is a mega-infrastructure project that connects China and the Eurasian Economies Area by overland and sea routes. Therefore, if it goes smoothly, It will be a new engine for economic development in China and the world, and It is expected to be a factor that will change the structure of the international economy. Especially, the Eurasian continent is likely to develop into the center of the global economy. But China's 'One Belt and One Load' initiative is not only macro and long-term, but also implies complexity, making it hard to be optimistic about development. China's 'One Belt and One Load' initiative is not only strongly promoted as a long-term national development strategy to be completed by 2049, but also strong economic complementarity between China and 'One Belt and One Load' consecutive countries. And many of the successive countries are expecting 'One Belt and One Load' construction. Therefore, there is no possibility at all. In particular, the possibility of development can not be completely ruled out, given the various policies of 'One Belt and One Load' currently being pursued by China. Even if it doesn't go smoothly, the process alone will have significant economic effects on China and neighboring countries, so it will be meaningful. With the help of information technology.

Operating Strategies for Education and Training Programs for Nurturing North Korean Construction Workers (북한 건설기능인력 양성을 위한 교육·훈련 프로그램 운영 전략)

  • Jung, In-Su;Lee, Giu;Park, Hyeong-Geun;Lee, Young-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.262-269
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    • 2019
  • This study was conducted to pave the way for the development and operation of education and training programs to nurture skilled North Korean construction workers. Such programs would help to meet the expanded demand for setting up infrastructure, which is the backbone of the two Koreas' economic cooperation and mutual development. To achieve this initiative, the targets and scopes of education and training were determined by classifying business types for education and training purposes by construction sector. Furthermore, each education and training course and their allocated time frames were analyzed. Issues related to inter-Korean economic cooperation in the border area were also analyzed to determine regional characteristics. Education and training programs were thus classified into three types of infrastructure units: society, industry, and life infrastructure units. Social infrastructure units are the common demand of the whole border area, including construction of roads, railways, and harbors, as well as inspection and maintenance. Industrial infrastructure units are programs for industrial facilities centering on the designated special economic zone in the western part of the border area. Life infrastructure units are programs for infrastructure facilities such as large, complex facilities and residential facilities for the eastern tourist belt side.

Design of Simple Shielding Handkerchief to Protect the Passenger's Thyroid (비행기 이용승객의 갑상선 차폐를 위한 간편한 손수건 고안)

  • Jung, Hongmoon;Jung, Jaeeun
    • Journal of the Korean Society of Radiology
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    • v.13 no.1
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    • pp.87-93
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    • 2019
  • Recently, the number of passengers using airplanes is rapidly increasing due to the increase of overseas travelers. Therefore, the probability of exposure to natural radiation due to altitude is increasing due to the increase in flight time. Cosmic-ray penetrates the Earth's magnetic field belt Van Allen, which is located at an altitude of 400 km to 1200 km. Most cosmic rays are blocked at Van Allen belt. However, cosmic-ray could be not completely blocked, and a small amount of cosmic-ray affects the earth. In general, if the altitude was increased by 100m, the natural exposure dose increased by 0.03 mSv on the Earth. In this study, I tried to minimize the exposure to natural radiation in airplanes when boarding airplanes. Especially, I was aimed to minimize radiation exposure by protecting the highly sensitive thyroid gland among human organs. According to the results of the study, the designed shielding handkerchief was able to shield cosmic natural radiation dose by more than 70%. In conclusion, the application of the shielding handkerchief made in this study can be effectively shield natural radiation.