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A study on the spectacles-wearing and eyesight health behavior of the middle school students (서울시내 일부 중학생의 시력 및 안경착용과 그에 따른 보건행태 조사연구)

  • Jeon, Ye-Jin;Kim, Myung
    • Korean Journal of Health Education and Promotion
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    • v.11 no.2
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    • pp.87-106
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    • 1994
  • Owing to the use of many cultural facilities, the elevation of life standards and the high level progress of industry, visual impairment was on increasing trends. Especially due to studying for many hours, the myopia of adolescents became a serious social issue. The purpose of this study was to understand adolescent's wearing glasses and eyesight condition, whether the primary myopia factor and the subjective symptoms were different between the myopia group and the normal group, between the wearing glasses group and the non-wearing glasses group, and the effect on physical, mental and study activity of myopia. The subject of investigation was 627 middle school students in Seoul and the investigation was accomplished from July 7th, 1993 to July 12th, 1993. The data were analyzed by the percentage, x²-test, t-test and ANOVA of SPSS. The results were as followed; 1. The rate of the right and left eyesights higher than 0.8 in the normal group was 47.0%, and those less than 0.7 in the myopia group was 53.0%. In the boy students, the normal group was 54.1%, the myopia group was 45.9%. In the girl students, the normal group was 39.2%, the myopia group was 60.8%. Therefore the girl students' myopia rates were higher than the boy students', and this result was significant(p<0.01). 2. The rate of wearing glasses of the middle school students was 44.6%. The rate of wearing glasses of the girl students was 56.8%. The rate of wearing glasses of the girl students was higher than that of the boy students 43.2%. The rate of necessary glasses of the middle school students was 6.1% and the rate of necessary glasses of the boy students was 7.9%, the rate of necessary glasses of the girl students was 4.1%. 3. In case of a family member of the student wear glasses, the rate of wearing glasses was higher. 4. In the myopia group, the main reason for not wearing glasses was "Uncomfortable"(63.3% in the boy students, 40% in the girl students). In case of the girl students, "Nonpermission of their parents" was 18.7% and remarkably higher than 5.1% in case of the boy students. 5. The factor of myopia was that "The bad attitude of watching TV closely" was 19.9%, that "The dimly-lit room" was 6.6%. 6. In order to protect eyesight, the rate of the students who practiced "Looking at something from afar 3∼4times a day" was 37.3%, the rate of the students who did "Eye exercise" was 17.5%, the rate of the students who took "A medicine for promoting nutrition" was 12.9%. The rate of taking the medicine was higher than 3.5% in the normal eyesight group. 7. After near working, the point of subjective symptoms was higher in the myopia group than in the normal group and in the wearing glasses group than in the unwearing group and in the girl students than in the boy students. 8. The longer time to watch TV, the higher point of subjective symptoms. The longer distance to watch TV, the lower point of subjective symptoms(p<0.05).

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A Framework of Recognition and Tracking for Underwater Objects based on Sonar Images : Part 2. Design and Implementation of Realtime Framework using Probabilistic Candidate Selection (소나 영상 기반의 수중 물체 인식과 추종을 위한 구조 : Part 2. 확률적 후보 선택을 통한 실시간 프레임워크의 설계 및 구현)

  • Lee, Yeongjun;Kim, Tae Gyun;Lee, Jihong;Choi, Hyun-Taek
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.3
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    • pp.164-173
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    • 2014
  • In underwater robotics, vision would be a key element for recognition in underwater environments. However, due to turbidity an underwater optical camera is rarely available. An underwater imaging sonar, as an alternative, delivers low quality sonar images which are not stable and accurate enough to find out natural objects by image processing. For this, artificial landmarks based on the characteristics of ultrasonic waves and their recognition method by a shape matrix transformation were proposed and were proven in Part 1. But, this is not working properly in undulating and dynamically noisy sea-bottom. To solve this, we propose a framework providing a selection phase of likelihood candidates, a selection phase for final candidates, recognition phase and tracking phase in sequence images, where a particle filter based selection mechanism to eliminate fake candidates and a mean shift based tracking algorithm are also proposed. All 4 steps are running in parallel and real-time processing. The proposed framework is flexible to add and to modify internal algorithms. A pool test and sea trial are carried out to prove the performance, and detail analysis of experimental results are done. Information is obtained from tracking phase such as relative distance, bearing will be expected to be used for control and navigation of underwater robots.

Study on Improvement for selecting the optimum voice channels in the radio voice communication (무전기 음성통신에서 최적음성채널 선택을 위한 개선방안에 관한 연구)

  • Lew, Chang-Guk;Lee, Bae-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.2
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    • pp.171-178
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    • 2016
  • An aircraft in flight and ATC(: Air Traffic Controllers) working in the Ground Control Center carry out a voice communication using the radio. Voice signal to be transmitted from the aircraft is received to a plurality of terrestrial sites around the country at the same time. The ATC receives the various quality of voice signal from the aircraft depending on the distance, speed, weather conditions and adjusted condition of the antenna and the radio. The ATC carries out a voice communication with aircraft in the optimal conditions finding the best voice signal. However, the present system chooses the values of the CD(: Carrier Dectect) which is determined to be superior to, based on the input voice level, as optimal channel. Thus this system can not be seen to select the optimal channel because it doesn't consider the effect of the noise which influences on the communication quality. In this paper, after removing the noise in the voice signal, we could give the digitized information and an improved voice signal quality, so that users can select an optimal channel. By using it, when operating the training eavesdropping system or the aircraft control, we can expect prevention accident and improvement of training performance by selecting the improved quality channel.

The fabrication of PVDF organic thin films by thermal evaporation deposition method and their molecular orientation properties (열증착법을 이용한 PVDF 유기박막의 제조와 분자배향특성)

  • 임응춘;이덕출
    • Journal of the Korean Vacuum Society
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    • v.6 no.2
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    • pp.122-128
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    • 1997
  • In this study, the PVDF organic thin films were fabricated by thermal evaporation deposition which is one of the dry-processing methods. The distance from heat source to substrate was 5 cm. The substrate temperature was maintained at $30 ^{\circ}C$ during deposition. The working pressure was about $2.0\times10^{-5}$Torr and the temperature of heat source was increased at the rate of 6 to $8^{\circ}C$/min. At $270^{\circ}C$, the shutter was opened and the deposition of PVDF has stared. As the electrical field intensity increased, $\alpha$ peaks such $530\textrm{cm}^{-1},795\textrm{cm}^{-1},1182\textrm{cm}^{-1}$ decreased, and $\beta$ peaks such as $510\textrm{cm}^{-1},1273\textrm{cm}^{-1}$ increased. The intensity of $530\textrm{cm}^{-1}$ peak was stronger than that of $510\textrm{cm}^{-1}$ peak velow the 71.4 kV/cm, intensity of electrical field. This result showed the characteristic of film mainly due to $\alpha$-mode. According to these results, the molecular structure of PVDF thin film is transformed from $\alpha$-mode with TGT or TG'T to $\beta$-mode with planar zigzag structure TT, as increasing of intensity of electrical field.

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Research for Thickness Change of Denture Base in Flask when Injecting Valplast Flexible Partial Denture Resin (발플라스트 레진 주입 시 발생되는 의치상의 두께변화에 관한 연구)

  • Jang, Wan-Young;Kim, Bu-Sob;Chung, In-Sung
    • Journal of Technologic Dentistry
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    • v.30 no.2
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    • pp.47-56
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    • 2008
  • This is a research for thickness change of denture base according to the shape of sprue & investment position of denture base in flask when injecting polyamid base resin for flexible partial denture as a part of study for Valplast among the flexible partial denture with a nylon base. It has been introduced several kinds of flexible partial denture product with a nylon base, but Valplast is the most widely used product among them. Valplast has been the most generally used material today since developed in 1950s in the United States as a material for flexible partial denture. Valplast is much more aesthetic than general metal-acrylic partial denture due to its translucent pink color and biocompatibility in terms of material characteristic. It keeps its flexibility for a long time after production, imposes a less burden on the teeth used as abutment, and it can be easily insert and remove due to its particular suppleness. Moreover, it is felt like real teeth more than metal-acrylic partial denture when being put in and takes alveolar bone under good protection since it receives occlusal force equally under the denture base. The most outstanding feature of Valplast is flexibility. The extent of its flexibility is determined by width & thickness of denture base. Considering general working procedure of Valplast, it can be seen that the thickness of denture base formed out of wax is increasing by the pressure while injecting resin. This research is to decide and test on the thickness increasing of Valplast by injecting pressure and the hypothesis upon that and is to prepare the basis estimating the increasing extent of thickness of denture base on the basis of the test result. In this test, it is expected occlusal malposition & thickness increasing of denture base by injecting pressure according to 4 kinds of test data which are to select 3 types of sprue method settling the forefront position at which the test material of fixed standard can be invested and to position the test material at the rearmost part keeping the minimum distance to set sprue. For 4 kinds of injecting test by investment position & sprue type, 20 test materials, 5 for each test were produced and a pressure of 1,180Kg was given with automatic injector of air cylinder type. The results are as follows: 1. For the amount of thickness increasing of denture base by investment position, the thickness of front investment is less increasing than the one of rear investment. 2. For the amount of thickness increasing of denture base by sprue type, the thickness of straight decompression sprue type which can absorb the injecting pressure after injecting polyamide base resin is less increasing than the other sprue types.

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Development of a Fleet Management System for Cooperation Among Construction Equipment (건설장비 협업을 위한 플릿관리 시스템 개발)

  • Ahn, Seo-Hyun;Kim, Sung-Keun;Lee, Kwan-Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.3
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    • pp.573-586
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    • 2016
  • In construction jobs, a combination of various kinds of machinery is used to perform earthworks at a large-scale site. Individual equipments essentially cooperate with each other on task such as excavation, load, transfer and compaction. While other area have studied cooperation system, related study in domestic construction is in poor condition. In this study, construction equipment fleet management system is developed for solving this problem and find way to improving efficiency in earthworks site. The entire concept of the fleet management system, including its components and process, has been systematically outlined in this paper. An operational methodology has also been suggested, where a number of machines, such as the excavators, trucks and compactors, are chosen and further grouped into a cluster. A case study verify fleet management system's effectiveness on performing task package by comparing existing work method with methodology in this study. Fleet management system in this study is expected to curtail fuel consumption by the reduction of working time and moving distance. Furthermore, it can be anticipated to declining carbon emission effect.

Post-Medium and Postproduction: Contemporaneity of Contemporary Art (포스트-미디엄과 포스트프로덕션 : 포스트모더니즘 이후 현대미술의 '동시대성(contemporaneity)')

  • Chung, Yeon Shim
    • The Journal of Art Theory & Practice
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    • no.14
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    • pp.187-215
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    • 2012
  • In recent studies of art historical methodology, such as Critical Terms for Art History and The Art of Art History, subjectivity, identity, abjection, and other terms have been placed safely in the genealogy of contemporary art history. This paper questions the contemporaneity in the story of contemporary art in our time in relation to two other critical terms that have been regularly cited by contemporary critics, not only in Euro-American fields but also in Korea. The terms are postmedium and postproduction, respectively, as used by Rosalind Krauss and Nicolas Bourriaud. This paper stems from the critical condition in which art criticism and theory have their power in the rise of neo-liberalism. But this paper does not deal with the contemporary as a chronological term for art history but rather examines the three critical terms-contemporaneity, post-medium, and postproduction-that have garnered scholarly attention. I would like to put aside postmodernism for the moment; I don't disregard the postmodern condition although the death of postmodern critical terms has resulted in the loss of its polemical power in art worlds such as in exhibitions, etc. To look at "the postproduction in the age of post-medium age after postmodernism," I first explore Krauss's notion of post-medium because, unlike media artists like Lev Manovich and Peter Weibel, Krauss's post-medium condition is different and insists on medium specificity. In this sense, Krauss has turned out to be another Greenberg in disguise. For her, photography and video are expanded mediums after Greenberg, because Krauss has spent her life explicating those mediums. Under the Cup, her recent publication, came out in 2011, and discusses her desire to defend medium-specificity against the intermedia of installation art found ubiquitously in international exhibitions and biennales. Her usage of post-medium has been taken up by Weibel as postmedia in a broader sense. But whether the post-medium condition or the postmedia age, we nonetheless enter the new age of the contemporary. Consequently, this paper questions what constitutes contemporaneity in our times. It is said that there is nothing new on earth, yet I find original artistic strategies among the younger generation in the postmedia age. The contemporary justifies its place in art fields and criticism by keeping its distance from postmodernism although we still find the remnants of postmodern artistic practices and theoretical foundations. By looking at materials written by Terry Smith, I would like to examine contemporaneity as a rhetoric where artists, critics, and curators endeavor to set up a new spirit of criticism, distant from the past of modernism and postmodernism. In discussions, modernism and postmodernism act as catalysts interacting with each other while justifying their own place. In conclusion, my paper reaches to delineate where the contemporary finds its place among artists' responses and working methods. It explores the postproduction of the Internet and the World Wide Web generations, where images become data rather than representation (of modernism) and appropriation (of postmodernism). This paper analyzes Bourriaud's text, as well as relevant artists like Pierre Huyghe, Liam Gillick, and others. By examining the aforementioned critical terms, I would like to reconsider our own contemporary art in Korea, especially among young artists influenced by digital media and the World Wide Web in the 1990s.

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Study on Wet chemical Etching Characterization of Zinc Oxide Film for Transparency Conductive Oxide Application (투명 전도성 산화물 전극으로의 응용을 위한 산화아연(ZnO) 코팅막의 습식 식각 특성연구)

  • Yoo, Dong-Geun;Kim, Myoung-Hwa;Jeong, Seong-Hun;Boo, Jin-Hyo
    • Journal of the Korean Vacuum Society
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    • v.17 no.1
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    • pp.73-79
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    • 2008
  • In order to apply for transparent conductive oxide(TCO), we deposited ZnO thin films on the glass at room temperature by RF magnetron sputtering method. Deposition conditions for high transmittance and low resistivity were optimized in our previous studies. Under the deposition condition with the RF power of 200 W, target to substrate distance of 30 mm and working pressure of 5 mTorr, highly conductive($7.4{\times}10^{-3}{\Omega}cm$) and transparent(over 85%) ZnO films were prepared. Highly oriented ZnO film in the [002] direction were obtained with specifically designed ZnO targets. Systematic study on dependence of deposition parameters on electrical and optical properties of the as-grown ZnO films were mainly investigated in this work. And for application tests using these films as transparent conductive oxide anodes, wet chemical etching behaviors of ZnO films were also investigated using various chemicals. Wet-chemical etching behavior of ZnO films were investigated using various acid solutions. The concentrations of these different acid solutions were controlled to study the etching shapes and etching rate. ZnO films were anisotropically etched at various concentrations and wet etching led to crater-like surface structure. Also we firstly found that the etching rate and etching shapes of ZnO films strongly depended on the etchant concentrations (i.e. pH) and the etching rate is exponentially decreased with increasing pH values regardless of the acid etchants.

A Basie Community Health Survey in Rural Korea (Soyang-Myun) (소양면 지역사회 환경기초조사)

  • Choi, Sung-Yul
    • Journal of Preventive Medicine and Public Health
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    • v.6 no.1
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    • pp.133-160
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    • 1973
  • 1. Introduction Community medicine with the concept of comprehensive medical care and an ideal medical care delivery system not only for an individual or family but for the whole community has emerged. In April 1970, the Presbyterian Medical Center started a hospital based community health service project in order to improve the health of the people in rural areas. Prior to commencing a comprehensive medical care system, a family survey was needed. The major objective of this survey was to obtain information concerning the people and their environment so as to be able to plan and implement a comprehensive medical care program in Soyang-Myun. 2. Survey Method An interview using a family record form was carried out for each household. This family record form was designed to get information about demography, family planning, environmental sanitation and vital statistics. Prior to beginning, the members of the survey team were trained in interviewing techniques for three days. The team consisted of a public health nurse, four nurse-aides, a sanitarian and four health extension workers who are working in our project, The survey was carried out during the period November 1971 to March 1972. 3. Project area 1) Population of Soyang-Myun was 11,668; male, 5,962 and female, 5,706. Sex ratio: 104.5. 2) Households : 1,858 3) Family size: The average household consisted of 6.3 persons. 4) Educational level of householder a. Illiterate 13% b. No schooling but able to read 10% c. Preschool children 19% d. Primary school 47% e. Middle school 7% f. High school 3% g. College or University 1% 5) Occupational distribution of householders a. Farmer 67% b. Laborer 13% c. Office worker 4% d. Merchant 4% e. Industrial worker 2% f. Unemployed 8% g. Miscellaneous 2% 6) Religious affiliation a. No religion 74% b. Buddhist 12% c. Protestant 10% d. Catholic 4% 4. Survey results Living Environment : a. Home ownership 95% b. Kinds of roofing Straw-thatched house 84% Tile-roofed house 10% Slate-roofed house 5% Other 1% c. Floor space Less than 6 pyong 10% 6-10 pyong 53% 11-15 pyong 24% 16-20 pyong 9% More than 20 pyong 4% d. Radio ownership 80% Environmental Sanitation : a. the source of drinking water public well 49% private well 30% drainage water 9% steam water 8% well pump 3% water distribution system 1% b. Distance between well and toilet more than 16meters 38% 6-10 meter 31% 11-15 meters 14% Less than 6 meters 17% c. The status of well management Bad 72% Fair 26% Good 2% d. General sanitary state of house Bad 37% Fair 51% Good 12% e. House drainage system had no house drainage. 77% Family Planning : a. 24% of the people have used contraceptives, but 12% ceased to use them. 76% have never used contraceptives. b. used methods 1oop 68% oral pill 16% vasectomy 4% condom 1% tubal ligation 1% two or more methods 10% Maternal Health : a. The number of conceptions of housewives under 50 years of age. 11 times 26% 6 times 11% 5 times 11% 4 times 9% b. The place of delivery own house 88% hospital 1% others 11% Treatment of general sickness : a. The place of treatment Soyang Health Center 31% Hospital (private or otherwise) 26% Pharmacy 14% Herb medicine 5% Private care 5% No treatment 12% Miscellaneous 7% b. Usual causes of diseases Unknown 46% Tuberculosis 29% Neuralgia 8% CVA 3% Bronchitis 3% Others 11%

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Neuropsychological Approaches to Mathematical Learning Disabilities and Research on the Development of Diagnostic Test (신경심리학적 이론에 근거한 수학학습장애의 유형분류 및 심층진단검사의 개발을 위한 기초연구)

  • Kim, Yon-Mi
    • Education of Primary School Mathematics
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    • v.14 no.3
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    • pp.237-259
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    • 2011
  • Mathematics learning disabilities is a specific learning disorder affecting the normal acquisition of arithmetic and spatial skills. Reported prevalence rates range from 5 to 10 percent and show high rates of comorbid disabilities, such as dyslexia and ADHD. In this study, the characteristics and the causes of this disorder has been examined. The core cause of mathematics learning disabilities is not clear yet: it can come from general cognitive problems, or disorder of innate intuitive number module could be the cause. Recently, researchers try to subdivide mathematics learning disabilities as (1) semantic/memory type, (2) procedural/skill type, (3) visuospatial type, and (4) reasoning type. Each subtype is related to specific brain areas subserving mathematical cognition. Based on these findings, the author has performed a basic research to develop grade specific diagnostic tests: number processing test and math word problems for lower grades and comprehensive math knowledge tests for the upper grades. The results should help teachers to find out prior knowledge, specific weaknesses of students, and plan personalized intervention program. The author suggest diagnostic tests are organized into 6 components. They are number sense, conceptual knowledge, arithmetic facts retrieval, procedural skills, mathematical reasoning/word problem solving, and visuospatial perception tests. This grouping will also help the examiner to figure out the processing time for each component.