• Title/Summary/Keyword: Contact Characteristics

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A Characteristic of Deformation and Strength of Domestic Sands by Triaxial Compression Tests (삼축압축시험에 의한 국내 모래의 변형-강도 특성)

  • Park, Choon Sik;Kim, Jong Hwan;Park, Cheol Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.2
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    • pp.515-527
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    • 2014
  • This study conducted experiment for understanding engineering characteristics of domestic sands by examining standard sand and sand from Yokji Island and Nakdong River in terms of confining pressure, $K_0$, over consolidation and relative density factors through triaxial compression test. The test showed that deviator stress by strain positively changed as confining pressure and relative density grow while $K_0$ and over consolidation factors do not directly correlated with it. Angle of internal friction decreases as confining pressure increases which strengthens contact force between particles, and declines as relative density drops, whereas $K_0$ and over consolidation factors hardly affect the results. When it comes to volumetric strain, volume expansion decreases as confining pressure increase due to crushability and rearrangement of particles while $K_0$ and over consolidation shows same movement unconditionally, and relative density appears compressed as it grows at the beginning however it expands as axial strain increases. Modulus of elasticity ($E_{sec}$) by strain has tendency into convergence resulting in initial secant modulus of elasticity ($E_{ini}$) > secant modulus of elasticity($E_{sec}$) > tangent modulus of elasticity ($E_{tan}$). On the other hand, it grows as confining pressure and relative density increase while indicating similar modulus of elasticity ($E_{sec}$) regarding on $K_0$ and over consolidation. Slope of critical line (M) tended to decrease as confining pressure increases, follow same line according to $K_0$, confining pressure and relative density, and increase as relative density grows.

Improved Photoelectric Conversion Efficiency of Perovskite Solar Cells with TiO2:TiCl4 Electron Transfer Layer (TiO2:TiCl4 전자수송층을 도입한 페로브스카이트 태양전지의 광전변환효율 향상)

  • Ahn, Joon-sub;Kang, Seung-gu;Song, Jae-gwan;Kim, Jin-bong;Han, Eun-mi
    • Journal of the Microelectronics and Packaging Society
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    • v.24 no.4
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    • pp.85-90
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    • 2017
  • The $TiCl_4$ as a blocking material is adsorbed in the mesoporous $TiO_2$ electron transfer layer(ETL) of the Perovskite solar cell to prevent the direct contact between the FTO electrode and the photoactive layer(AL), and facilitate the movement of the electrons between $TiO_2:TiCl_4$ ETL and Perovskite AL to improve the photoelectric conversion efficiency(PCE). The structure of the perovskite solar cell is FTO/$TiO_2:TiCl_4$/Perovskite($CH_3NH_3PbI_3$)/spiro-OMeTAD/Ag. It was investigated that the dipping time of the $TiO_2$ into $TiCl_4$ aqueous solution affects on the photoelectric characteristics of the device. By the dipping for 30 minutes, the PCE of the perovskite solar cell with the $TiO_2:TiCl_4$ ETL was the highest 10.46%, which is 27% higher than the cell with $TiO_2$ ETL. From SEM, EDS, and XRD characterization on the $TiO_2:TiCl_4$ ETL and the perovskite AL, it was measured that the decrease of the porosity of the $TiO_2$ layer, the detection of the Cl component by the $TiCl_4$ adsorption, the cube-type morphology of perovskite AL, and shift of the $PbI_2$ peak of the perovskite AL. From these results, it was confirmed that the $TiO_2:TiCl_4$ ETL and the perovskite AL were formed.

Awareness of Major Zoonoses among Dairy Farmers in Gyeonggi Province (경기도 낙농업자의 주요 인수공통감염증 인지도)

  • Choi, Kum-Bal;Lim, Hyun-Sul;Lee, Kwan;Min, Young-Sun
    • Journal of agricultural medicine and community health
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    • v.35 no.4
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    • pp.339-349
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    • 2010
  • Objective: We surveyed awareness levels of brucellosis, Q fever and enterohemorrhagic Escherichia coli (EHEC) among dairy farmers in Gyeonggi Province to suggest directions for public education and public relations. Methods: We designed questionnaires to evaluate awareness of 3 major zooneses. We conducted a questionnaire survey to assess knowledge of the general characteristics of them, information sources for the awareness of zooneses, and the mode of transmission. Subjects were 716 workers from 482 dairy farms in Gyeonggi province. Results: The awareness levels for brucellosis, Q fever, and EHEC were 90.2%, 2.5% and 56.6%, respectively. Awareness of brucellosis and EHEC were tended to increase with higher number of school years. Television was the most common route of information for these zoonoses. Most common responses for questions concerning the method of transmission for each zoonoses, 'Contact with parturient fluid or placenta of animal' was 63.2% for brucellosis, 'Ingestion of raw meat or residual product' was 66.7% and 64.2% for Q fever and EHEC, respectively. The most common reason why dairy farmers think that it is difficult to prevent zoonoses was the inconvenience of wearing protection. Conclusions: Education programs for zoonoses, especially Q fever, are needed for dairy farmers. In addition, publicity information activities about prevention of zoonoses are needed for high risk groups, such as the dairy farmers surveyed.

A study on the CRM strategy for medium and small industry of distribution (중소유통업체의 CRM 도입방안에 관한 연구)

  • Kim, Gi-Pyoung
    • Journal of Distribution Science
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    • v.8 no.3
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    • pp.37-47
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    • 2010
  • CRM refers to the operating activities that always maintain and promote good relationship with customers to ultimately maximize the company's profits by understanding the value of customers to meet their demands, establishing a strategy which may maximize the Life Time Value and successfully operating the business by integrating the customer management processes. In our country, many big businesses are introducing CRM initiatively to use it in marketing strategy however, most medium and small sized companies do not understand CRM clearly or they feel difficult to introduce it due to huge investment needed. This study is intended to present CRM promotion strategy and activities plan fit for the medium and small sized companies by analyzing the success factors of the leading companies those have already executed CRM by surveying the precedents to make the distributors out of the industries have close relation with consumers to overcome their weakness in scale and strengthen their competitiveness in such a rapidly changing and fiercely competing market. There are 5 stages to build CRM such as the recognition of the needs of CRM establishment, the establishment of CRM integrated database, the establishment of customer analysis and marketing strategy through data mining, the practical use of customer analysis through data mining and the implementation of response analysis and close loop process. Through the case study of leading companies, CRM is needed in types of businesses where the companies constantly contact their customers. To meet their needs, they assertively analyze their customer information. Through this, they develop their own CRM programs personalized for their customers to provide high quality service products. For customers helping them make profits, the VIP marketing strategy is conducted to keep the customers from breaking their relationships with the companies. Through continuous management, CRM should be executed. In other words, through customer segmentation, the profitability for the customers should be maximized. The maximization of the profitability for the customers is the key to CRM. These are the success factors of the CRM of the distributors in Korea. Firstly, the top management's will power for CS management is needed. Secondly, the culture across the company should be made to respect the customers. Thirdly, specialized customer management and CRM workers should be trained. Fourthly, CRM behaviors should be developed for the whole staff members. Fifthly, CRM should be carried out through systematic cooperation between related departments. To make use of the case study for CRM, the company should understand the customer and establish customer management programs to set the optimal CRM strategy and continuously pursue it according to a long-term plan. For this, according to collected information and customer data, customers should be segmented and the responsive customer system should be designed according to the differentiated strategy according to the class of the customers. In terms of the future CRM, integrated CRM is essential where the customer information gathers together in one place. As the degree of customers' expectation increases a lot, the effective way to meet the customers' expectation should be pursued. As the IT technology improved rapidly, RFID (Radio Frequency Identification) appears. On a real-time basis, information about products and customers is obtained massively in a very short time. A strategy for successful CRM promotion should be improving the organizations in charge of contacting customers, re-planning the customer management processes and establishing the integrated system with the marketing strategy to keep good relation with the customers according to a long-term plan and a proper method suitable to the market conditions and run a company-wide program. In addition, a CRM program should be continuously improved and complemented to meet the company's characteristics. Especially, a strategy for successful CRM for the medium and small sized distributors should be as follows. First, they should change their existing recognition in CRM and keep in-depth care for the customers. Second, they should benchmark the techniques of CRM from the leading companies and find out success points to use. Third, they should seek some methods best suited for their particular conditions by achieving the ideas combining their own strong points with marketing. Fourth, a CRM model should be developed that will promote relationship with individual customers just like the precedents of small sized businesses in Switzerland through small but noticeable events.

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A Study on Characterization of Formation and Reduction of THMs in Water Treatment Process (정수처리공정별 THMs 발생특성과 저감방안에 대한 연구)

  • Ka, Gil-Hyun;Bae, Min-Ho;Lee, Jun-Ho;Ahn, Chi-Hwa;Han, Ihn-Sup;Min, Byung-Dae
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.7
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    • pp.721-728
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    • 2008
  • DBPs(Disinfection By-Products) are most formed through the reactions between chlorine and NOM(Natural Organic Matter) in water treatment. In this study, occurrence of DBPs including THMs(Trihalomethanes) is evaluated. Also, influencing factors by the seasons and raw water quality were investigated for correlation among them and the characteristics of THMs formation by prechlorination process. This study investigated the operation condition for THMs removal depending on raw water quality. Water treatment plant from intake station to gauging well flows for about 10 hours in Y Water Supply Office. It is limited to control of THMs formation because of excessive reaction time between chlorine and THMs precursors in the intake station. Therefore, as multi-points prechlorination from intake station to gauging well, THMs formation was decreased in the water treatment, and it was willing to prevent overdosage of chlorine. The concentration of THMs was 0.021 mg/L in the summer, 0.015 mg/L in the winter, respectively. Also, THMs formation showed that 0.013 mg/L in the water of gauging well after prechlorination, 0.014 mg/L in the flocculation/sedimentation/filtration, 0.016 mg/L in the water after postchlorination, respectively. THMFP(Trihalomethane Formation Potential) removed 42.7% and 50% through the flocculation/sedimentation and filtration, respectively, and it is similar TOC removal efficiency. In this study, multi-points prechlorination from intake station to gauging well decreases in contact time and concencrations of NOM and chlorine. Also, it decreases in THMs and amount of chlorine uesd. In the result of multi-points prechlorination in the summer, the concentration of THMs was 0.013mg/L in the treated water. In view of these facts, THMs formation can be decreased approximately 50%.

Petrology of the Blastoporphyritic Granite Gneiss in the Southwestern Part of the Sobaegsan Massif (소백산육괴 서남부의 잔류반상 화강편마암의 암석학적 연구)

  • Lee, Choon-Hee;Lee, Sang-Won;Ock, Soo-Seck;Song, Young-Sun
    • Journal of the Korean earth science society
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    • v.22 no.6
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    • pp.528-547
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    • 2001
  • The blastoporphyritic granite gneiss (BPGN) including much alkali-feldspar megacrysts occurs in Jiri mountains area, southwestern part of Sobaegsan massif, Korea. The BPGN is formed gneiss complexes with other gneisses in Precambrian. The BPGN was named as porphyroblastic gneiss with porphyroblasts of alkali-feldspar megacrysts by other researchers, but the BPGN includes of euhedral alkali-feldspars (microcline), and the boundary with the granitic gneiss represents sharp contact as intrusive relationship. The BPGN mainly composes of alkali-feldspar megacrysts, quartz, plagioclase, K-feldspar and biotite some almandine and accessary minerals are muscovite, chlorite, apatite, zircon and opaques. The alkali-feldspar is microcline with perthitic texture. An content of plagioclases show 30 to 40. Biotites occur two type, one is Brown biotite which shows compositional ranges of Mg/Fe+Mg ratios from 0.38 to 0.52, the other is Green Bt. which is retrograde product. Camels to be various sizes and shapes have composition of almandine with 73 to 80 mole percent, but represent retrogressive zoning from core (X$_{pyr}$: 15.9${\sim}$20.8) to rim (X$_{pyr}$:13.7${\sim}$15.9) to be evidence of retrograde metamorphism. Megacrysts of alkali-feldspar in the BPGN show rectangular shape of euhedral and some become ellipsoidal or spheroidal in shape and the average size up to 20 cm long. The megacryst includes of biotite, plagioclase and quartz, and rarely euhedral apatite as inclusions. In petrochemistry the BPGN represents granodiorite composition, characteristics of peraluminous S-type granitoid and calc-alkaline features.

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An Empirical Study on Successful Factor of Local Mobile App One-Person Creating Company : The Moderating Effects of Social Capital (지역 모바일 앱 1인 창조기업의 성공요인에 관한 실증분석 : 사회적 자본의 조절효과를 중심으로)

  • Cheon, Phyeong Uk;Chung, Dong Seop;Ock, Young Seok
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.9 no.2
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    • pp.201-219
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    • 2014
  • The Republic of Korea in the real economy to a knowledge economy, and a center of creativity and imagination in the creative economy is changing the paradigm. As the core of creating economic, creative industries with the technology and information play an important role in the industry individuals. In order to solve the problem of the polarization of the economy and high youth unemployment rate of Korea, to recognize the role of the creative industries, as objection part, dimensions pan-national and one creative companies in industries of Mobile Apps various policies that support has been promoted. Support these policies to be able to contribute to the establishment of the success of mobile apps one-person creating company, we performed this study targeting one-person company that creates mobile apps area, we conducted a demonstration study of success factors, and thus more effective and efficient in an attempt to seek out support measures. In this study, we derive a research 4 hypothesis about the success factors of one creative enterprise through literature discussion, a study was made on the basis of empirical data of one-person company that creates mobile apps. The results of the analysis, first, if the development rate of the mobile application technology is fast and a new competition associated product is appeared, it was possible to find a tendency to be higher at the performance quantitative companies. Second, if the founder is a founding for the benefit and rewarding work and come to terms with the risk, it was possible to discover tends to be higher achievement quantitative. Third, if one-person company select a target market with capture intensively, it was possible to find a tendency for higher qualitative results. Fourth, it could be found that the reliability of the contact frequency of the network related performance business environment these characteristics enterprise management strategy and act as a significant modulatory effect. Provision of information relating to management and entrepreneurship education to be one creative enterprise is required, these results suggest that there is a provision continuing need for the opportunity to be able to meet and network and reliable variety have. In this study, to take advantage to promote the elimination measures that can increase the likelihood of success of the company of institutions to support one company that creates knowledge-based, such as in the field of mobile application.

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An Experimental Study on Dynamic Behavior Evaluation of Transitional Track (접속부 궤도의 동적거동분석을 위한 실험적 연구)

  • Cho, Sung-Jung;Choi, Jung-Youl;Chun, Dae-Sung;Kim, Man-Cheol;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1379-1385
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    • 2007
  • In domestic transitional zone design, there is regulation to prevent generation of irregular substructure behaviors that negatively influence in prevention of plasticity settlement on approach section and contact section as well as relieve overall track rigidity by reducing sectional foundation and track stiffness difference, but design guideline that considers dynamic behavior of transitional track in actual service line is very insignificant. Therefore in this study, characteristics of transitional track dynamic behaviors by substructure stiffness are researched and measured dynamic response of transitional track by substructure stiffness in order to prove correlation between substructure and track and calculate elasticity(stiffness) and track load of transitional track by using measurement and formula to provide basic information for developing design guideline considering dynamic behavior of service line transitional track.

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A Study on the Correlation of Sijo with Akjang (시조와 궁중 악장의 관계)

  • Cho, Kyu-Ick
    • Sijohaknonchong
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    • v.25
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    • pp.145-174
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    • 2006
  • The purpose of this study is to research the correlation of Sijo with Akjang. In Joseon Dynasty, the contact of folk music and court music was brisk. Although they had some political premises, many Jeongjaes presented in the royal court parties accepted Gagok, one of the representative folk song genres. It was an eye-opening matter. The song words sung by Gagok music accompaniment were the lyrics of Sijo. We can give Sijo that was used in diverse royal court parties as an typical example about introduction of folk music to the court music. A lot of Goryeo Dynasty's Jeongjaes were introduced to Joseon Dynasty nearly as they are. Naturally so most Sokak-gasas were. Bukjeon was sung to Jinjak tune which Jeong-gwajeong was sung. Bukjeon in the music book Akhak-Guebum is a long song, but instead Bukjeons in the music book Geumhapjabo and Yang'geum-sinbo are short. It suggests that the poetic form of Sijo was introduced to the Lyric of royal court music from a point of time in the early Joseon Dynasty. Especially, Bukjeon had been continued to the late Joseon Dynasty after exchanging to the lyric form of Sijo. Bukjeon had been used In the royal court to the first half of Joseon Dynasty It became established in the repertory of Gagok after spreading to people out of court. Turnover from the long Bukjeon to the short was a result that the folk music influenced royal court music. Bukjeon. song words praying King's longevity. was used in the diverse situations such as a small royal parties, royal archery, and King's outing. It can be a clue that the Korean song words continued to late Joseon Dynasty were used for the lyric of royal court music. In the correlation of the poetic form of Sijo and Akjang, we can find out some characteristics different from our common sense to distinguish royal court music from folk music.

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Reliability Verification of FLUKA Transport Code for Double Layered X-ray Protective Sheet Design (이중 구조의 X선 차폐시트 설계를 위한 FLUKA 수송코드의 신뢰성 검증)

  • Kang, Sang Sik;Heo, Seung Wook;Choi, Il Hong;Jun, Jae Hoon;Yang, Sung Woo;Kim, Kyo Tae;Heo, Ye Ji;Park, Ji Koon
    • Journal of the Korean Society of Radiology
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    • v.11 no.7
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    • pp.547-553
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    • 2017
  • In the current medical field, lead is widely used as a radiation shield. However, the lead weight is very heavy, so wearing protective clothing such as apron is difficult to wear for long periods of time and there is a problem with the danger of lethal toxicity in humans. Recently, many studies have been conducted to develop substitute materials of lead to resolve these problems. As a substitute materials for lead, barium(Ba) and iodine(I) have excellent shielding ability. But, It has characteristics emitting characteristic X-rays from the energy area near 30 keV. For patients or radiation workers, shielding materials is often made into contact with the human body. Therefore, the characteristic X-rays generated by the shielding material are directly exposured in the human body, which increases the risk of increasing radiation absorbed dose. In this study, we have developed the FLUKA transport code, one of the most suitable elements of radiation transport codes, to remove the characteristic X-rays generated by barium or iodine. We have verified the reliability of the shielding fraction of the structure of the structure shielding by comparing with the MCPDX simulations conducted as a prior study. Using the MCNPX and FLUKA, the double layer shielding structures with the various thickness combination consisting of barium sulphate ($BaSO_4$) and bismuth oxide($Bi_2O_3$) are designed. The accuracy of the type shown in IEC 61331-1 was geometrically identical to the simulation. In addition, the transmission spectrum and absorbed dose of the shielding material for the successive x-rays of 120 kVp spectra were compared with lead. In results, $0.3mm-BaSO_4/0.3mm-Bi_2O_3$ and $0.1mm-BaSO_4/0.5mm-Bi_2O_3$ structures have been absorbed in both 33 keV and 37 keV characteristic X-rays. In addition, for high-energy X-rays greater than 90 keV, the shielding efficiency was shown close to lead. Also, the transport code of the FLUKA's photon transport code was showed cut-off on low-energy X-rays(below 33keV) and is limited to computerized X-rays of the low-energy X-rays. But, In high-energy areas above 40 keV, the relative error with MCNPX was found to be highly reliable within 6 %.