• Title/Summary/Keyword: Specific force

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A Study on the Performance Certification System of Inspection and Diagnostic Equipment for Infrastructure using Advanced Technologies (첨단기술을 이용한 시설물 점검 및 진단장비 성능인증체계에 대한 연구)

  • Hong, Sung-Ho;Kim, Jung-Gon;Cho, Jae-Young;Kim, Do-Hyoung;Kim, Jung-Yeol;Kim, Young-Min;Lee, Dong-Wook
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.97-111
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    • 2021
  • Purpose: It is expected that various infrastructures diagnosis equipment will be needed as infrastructures management is strengthened to implement the Framework Act on Sustainable Infrastructure Management. It is necessary for a certification system to supply certified products of a reasonable level in accordance with market requirements for various convergence equipment. This paper deals with the introduction of certification system of inspection and diagnosis equipment for infrastructure using advanced technologies. Method: The basic elements, systems and procedures of certification system were reviewed through analyzing and comparing the existing similar certification system in Korea. In addition, a survey was conducted on a catalog method and the minimum performance criterion (sampling survey and complete enumeration survey) to equipment developers (manufacturers), clients and equipment users. Result: This survey showed that clients preferred complete enumeration method on the basis of minimum performance, and equipment users also preferred complete enumeration survey and sample survey, for minimum performance, at a similar rate. On the other hand, equipment developers preferred the catalog method. Conclusion: Clients and users who are the users of the diagnostic equipment preferred the minimum performance criterion because their trust in quality is important. On the other hand, developers(manufacturers) preferred the catalog method which adopts self certification because it is regulated in developing various products. There is no specific plan for the minimum performance standards required for the introduction of the method which users demand, at present. In addition, it is not desirable to force to introduce a certification system because it requires a considerable period of study to prepare the specific standards. Therefore, it is appropriate to operate the system for a certain period of time centering around the catalog method for the stable and continuous development of the infrastructure diagnosis and test equipment market in Korea. Also, it is effective to expand and develop the certification system to the extent that it minimizes the impact on the market when specific plans for the standards are prepared in the future.

A Study for the Optimal Development Strategy of Air Cargo in Size and AHP Survey Analysis of Each Potential Decision-Making Group (한국형 전술수송기의 적정 개발 규모와 의사결정 영향집단별 AHP조사 분석에 관한 연구)

  • Jung, Byung-Ho;Kim, Ik-Ki
    • Journal of the military operations research society of Korea
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    • v.34 no.3
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    • pp.31-40
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    • 2008
  • The aircraft manufacturing industry is a profitable business and has the potential to be an important export business. Our trade deficit needs to be improved in aircraft manufacturing part. Our national aircraft industry, which has been recognized for its quality in many domestic and international Air Shows, has developed the T/A-50 aircraft from the origins of the KT-1. With the ongoing development of the next generation fighter planes and helicopters, business for the next generation domestic air cargo has bright prospects. Judging by the history of the overseas air force dispatch during the Vietnam, Gulf, and Iraqi wars whose main mission was air transportation, there will be many opportunities to show the excellence of Korean air cargo in the future. The purpose of this study is to discover the optimal scale of air cargo development using the AHP method. The authors evaluated the scale of air cargo in size and capacity based on the following 5 standards used Korean developing airliner: usability, economics, technology, safety, and environmental friendliness. Then, the authors modified specific standards suitable for air cargo based on literature review Decision-making groups were chosen for suitability of expert staff in charge because they could represent for leading opinions in this specialized area especially as in practical aspects. The participants of the evaluation were pilots, transportation officers and management staff in the KAI who have experienced over 5years.

A Study on the Fashion Journalism in the Field of Daily Newspaper (한국(韓國) 패션저널리즘의 현황(現況) 연구(硏究)(1) - 5개 종합일간지(綜合日刊紙) 기사(記事)를 중심(中心)으로 -)

  • Lee, Sung-Hee;Cho, Kyu-Hwa
    • Journal of Fashion Business
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    • v.8 no.4
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    • pp.45-59
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    • 2004
  • The purpose of this study is to discover the present situation of fashion journalism, which is a collaborator and watchdog of the fast-growing fashion business industry, then to proffer fundamental data for the setting of desirable fashion journalism in the field of newspaper. Unlike magazine and internet news service which are focused on a specific group, daily newspaper has a far-reaching influence without regarding the age, gender and social status of the readers. Therefore, how newspaper deals with fashion and fashion phenomena has immense influence on the attitude and understanding of common people on fashion. Defining fashion journalism is an activity of gathering and mediating of various ideas and opinions on fashion, the beginning of fashion journalism of newspaper traces back to the late of 19th century. From then to the period of Japan's occupancy by force, newspaper used fashion articles to lead enlightenment of lifestyle. After Korean War, newspaper was one of the main path of in-flowing western culture and fashion trend till 1970s. During $1980s{\sim}1990s$, fashion articles in newspaper were separated from woman and family section and fashion journalism made their own way to a specialized field. In the beginning of 21st century, fashion journalism in the field of newspaper is armed with more various and profound contents then ever, but it is also true fashion journalism is not free from accusation of commercialization and agitation of preference on imported luxury goods. Today fashion articles of daily newspapers are not subordinated to the common idea, 'fashion is only for women'. Fashion articles deals with men as well as women. Information on new products is regarded more important than fashion trend. Articles are not restricted in the fashion section. It means fashion journalism is expanding its territory to business section, opinion section and so on. However, fashion news dealing with aged people or young children are very rare. It suggests target readers of fashion news are concentrated on the people who have a considerable buying power. An main article usually has more than 3 photos. That means not only photos in fashion news are established as essential visual information today but also commercialization of fashion news makes rapid progress in this field. Also the considerable dependancy on the information sources from manufacturing side can be a problem of sustaining accuracy and impartiality of news.

Internal Components Arrangement of MR Damper Landing Gear for Cavitation Prevention (캐비테이션 방지를 위한 MR 댐퍼형 착륙장치의 내부 형상 배치에 대한 연구)

  • Joe, Bang-Hyun;Jang, Dae-Sung;Hwang, Jai-Hyuk
    • Journal of Aerospace System Engineering
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    • v.14 no.5
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    • pp.33-41
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    • 2020
  • The landing gear of an aircraft is a device that absorbs and dissipates shock energy transmitted from the ground to the fuselage. Among the landing gears, the semi-active MR damper landing gear is supposed to show high-shock absorption efficiency under various landing conditions and secure the stability when out of control. In the case of the MR damper landing gear using an annular channel rather than orifice, Amesim, a commercial multi-physics program, is considered as more useful than the conventional two-degree-of-freedom model because the damping force generated by the pressure drop through the flow annular path can cause cavitation in the low-pressure chamber of the MR damper with a specific internal structure. In this paper, the main dynamic characteristics of the MR damper landing gear with an annular type flow path structure has been analyzed under the condition of cavitation. Based on the analysis results using Amesim, a design guideline for the MR damper flow path that prevents cavitation has been proposed based on the modification of the arrangement of internal components of the damper. The guideline was verified through a drop simulation.

Dental Management of Pediatric Hydrocephalus (소아 수두증 환자의 치과적 관리)

  • Kim, Mijun;Park, Howon;Lee, Juhyun;Seo, Hyunwoo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.44 no.2
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    • pp.228-234
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    • 2017
  • Hydrocephalus is a condition in which the volume of cerebrospinal fluid in the cerebral ventricles is abnormally elevated. Hydrocephalus patients may show macrocephaly and delayed development. Ventriculoperitoneal shunt is the most commonly used treatment but ventriculoatrial shunt is another treatment option. This report discusses the dental management process employed for a 7-year, 6-month old patient with ventriculoperitoneal shunt-treated hydrocephalus. This patient showed dental caries on the deciduous molars, facial swelling, macrocephaly and delayed development. Pulpectomy was performed on the deciduous molars under nitrous oxide sedation and mild protective stabilization. This patient did not appear to have any specific complications until the latest follow-up and was scheduled for the management of overall oral hygiene, development of permanent teeth, and craniofacial asymmetry through periodic follow-up. During dental treatment of shunt-treated patients, care should be taken to avoid applying excessive force to the catheter running along the patient's neck to prevent the displacement of the catheter. A referral to a neurosurgeon is recommended for patients with ventriculoatrial shunts for prophylactic antibiotics. As hydrocephalus patients grow, they may show craniofacial asymmetry or differences in the calcification of the permanent teeth, and require periodic oral and craniofacial assessment.

A Three-Way Collaborative NPD Network between a Large Retailer and Small and Medium-Sized Suppliers: A Case of Win-Win Growth (대형소매업체와 중소납품업체들 간 삼자 협력 네트워크에 의한 신제품개발: 대·중·소 동반성장 사례)

  • Jun, Jongkun;Lim, Sooyeon;Kim, Jooyoung
    • The Journal of Small Business Innovation
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    • v.19 no.2
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    • pp.37-52
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    • 2016
  • Making efforts to break down the barriers between the intra-company departments as well as cooperating with external partners can become the driving force to create a successful innovation in the new product development (NPD) process. This study deals with how the key factors of collaborative innovation success are working in the process of NPD collaboration. Using case analysis of the NPD process, where a large retailer and small and medium-sized suppliers cooperate, we found that the small and medium-sized suppliers achieved greater 'short-term' performances in the collaboration than the large firm, although the long-term performance is not clear. Among the six antecedents of innovation success, relationship-specific investment played a critical role in motivating the supplier's participation in the NPD process. Adopting a 'closed' network in which the two suppliers interact directly with each other and create new knowledge for the NPD process played an important role in producing a quality product in a reduced development time. Unlike previous studies about the retailer-supplier cooperation for NPD in the food industry suggesting that position differences cause communication problems which is a major obstacle to the NPD success. This study suggests that large retailer's initiative role is a critical success factor in the NPD by the cooperation between small and medium-sized suppliers and large retailers.

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Study on the hydrophobic modification of zirconia surface for organic-inorganic hybrid coatings (유-무기 하이브리드 코팅액 제조를 위한 지르코니아 표면의 소수화 개질 연구)

  • Lee, Soo;Moon, Sung Jin;Park, Jung Ju
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.2
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    • pp.260-270
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    • 2017
  • Zirconia has white color and physical, chemical stability, also using in high temperature materials and various industrial structural ceramics such as heat insulating materials and refractories due to their low thermal conductivity, excellent strength, toughness, and corrosion resistance. If hydrophobically modified zirconia is introduced into a hydrophobic acrylate coating solution, the hardness, chemical, electrical, and optical properties will be improved due to the better dispersibility of inorganic particle in organic coating media. Thus, we introduced $-CH_3$ group through silylation reaction using either trimethylchlorosilane(TMCS) or hexamethyldisilazane(HMDZ) on zirconia surface. The $Si-CH_3$ peaks derived from TMCS and HMDZ on hydrophobically modified zirconia surface was confirmed by FT-IR ATR spectroscopy, and introduction of silicon was confirmed by FE-SEM/EDS and ICP-AES. In addition, the sedimentation rate result in acrylate monomer of the modified zirconia showed the improved dispersibility. Comparison of the sizes of a pristine and the modified zirconia particles, which were clearly measured not by the normal microscope but by particle size analysis, provided a pulverizing was occurred by physical force during the silylation process. From the BET analysis data, the specific surface area of zirconia was approximately $18m^2/g$ and did not significantly change during modification process.

A Study on the Symbolic Meaning of the Costume Colours (복색 상징적 의미에 관한연구)

  • 이순홍
    • Journal of the Korean Society of Costume
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    • v.30
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    • pp.85-99
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    • 1996
  • This study has been made to examine the symbolic meaning of our traditional costume colours based on the theory of yin-yang Wu-hsing the interaction of yin and yang with the rotation of the five agents wood firt earth metal and waters. Presenting the spirt and the life of our race the costume culture has been keep-ing its own systematic symbol. Being sensible the colour has to be under-stood as the colour sense therefore the cos-tume colour has begun to have the symbolic meaning with the feeling or the mental value. According to the theory of yin-yang wu-hsing the costume colour has presented our racial sprit way of thinking and way of life for a long time and it has become the tra-ditional culture at last. Based on the doctrine of cosmic harmony through the motion of yin and yang or the passive and active elements are their five agents form the material force of everything. The order of nature has its counterpart in five symbolic costume colours wood-blue ; fire-red: earth-yellow; metal-white: water-black. The five colours are called the primary colours. which produce the next compound colours. Accepted in the social system as well as the social stats the costume colour has set up systematically. The theory of Yin-yang Wu-hsing has given the five colours the symbolic meanings and its mainstream has been the function of Sangsaeng and Sangeuk which are genera-ted by the power of virture. The former is mu-tually beneficial while the latter destructive. The colour as a costume colour has been made distinction between the colour of the up-per classes and the colour of the middle and lower classes and the specific colour has presented the symbolic meanings. The yeollow the red and the purple have been regarded as the colour of king queen and upper classes Being the colour recognition the costume colour has been established by the society and the race generally Implied the spiritual elements the colour recognition could select the lucky colour in accordance with one's des-tiny. Besides the colour recognition has begun to appear as the racial costumes to protect the society and to pray for good fortune. According to the theory of Yin-yang Wu-hsing the costume colour has been forming through our long history and has become our costume culture. Therefore the colour of the costume has signified not only the colour sense but also the important symbolic meanings.

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Magnetoresistive Effect in Ferromagnetic Thin Films( II) (강자성체 박막(Co-Ni)의 자기-저항효과에 관한 연구(II))

  • Chang, C.J.;Yoo, J.Y.;Nam, S.W.;Son, D.R.
    • Journal of Sensor Science and Technology
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    • v.3 no.1
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    • pp.68-77
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    • 1994
  • Grid type 70Ni-30Co thin films on slide glass at $250^{\circ}C$ has been fabricated to develope. From fabricated sensors using above process, we investigated the relation of temperature, resistivity, line width to magnetoresistance and we obtained the following results after observation of coercive force, saturated magnetization, maxium usable sensitivity, delay time, slew rate, white noise, resolution of the sensors. We confirmed that the $600{\AA}$ thin film at $250^{\circ}C$ formed crystalized magnetic anisotropy spontaneously and the sensor using the thin film had capability of detecting magnetic field with sensitivity of 230 nT. In these devices, the magnetoresistance change was increased linearly in ${\pm}10$ Oe range, and the magnetoresistance effect was increased when the ratio between line width and length was increased. When the devices was soldered using indium, the temperature-resistivity coefficient showed $8{\times}10^{-3}/deg$ and increased during the specific properties as magnetic field sensor were weakened. In this studies, the coercive forces of the films were about 5.1 A/cm and saturated magnetizations were 0.64 T, and the delay time in these devises was $5{\mu}s$ and slew rate showed 0.39 $Oe/{\mu}s$ and white noise was -120 dB.

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Experimental Analysis on Vibration of Composite Plate by Using FBG Sensor System (브래그 격자 센서 시스템을 이용한 복합재 평판 진동의 실험적 해석)

  • Kim, Dae-Hyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.5
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    • pp.436-441
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    • 2009
  • A fiber optic sensor is prospective to be applied to structural health monitoring. Especially, a fiber Bragg grating(FBG) sensor is one of the most popular sensors for the structural health monitoring. The FBG sensor has several demodulation systems for tracking the shift of the Bragg wavelength. The dynamic bandwidth is dependent on the demodulation system. In this paper, the sensing mechanism is that the slope of the optical spectrum of FBG could be used as its sensitivity when the tunable laser shot the monochromatic laser wavelength at the highest slope point. In this technique, the high sensitivity is guaranteed even though the sensing range is limited. In an example of the application, the composite plate embedding a FBG sensor was manufactured by using an autoclave method and the above sensing mechanism was applied to the composite plate. Firstly, the natural frequencies of the plate were successfully measured by the FBG sensor during the impact hammer test. Secondly, a high-power speaker was used to force the plate to be vibrated at the specific frequency that was one of the natural frequencies. During the shaking, the FBG sensor measures the dynamic characteristics and ESPI was also used to measure the mode shape. From the two dynamic tests, the availability of the FBG sensor system and the ESPI was proven as a technique for measuring the dynamic characteristics of composite structure.