• Title/Summary/Keyword: engineering property

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Analysis of runoff aggregation structure and energy expenditure pattern for Choyang creek basin on the basis of power law distribution (멱함수 법칙분포를 기반으로 한 조양하 유역의 유출응집구조와 에너지소비 양상에 대한 해석)

  • Kim, Joo-Cheol;Cui, Feng Xue;Jung, Kwan Sue
    • Journal of Korea Water Resources Association
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    • v.50 no.11
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    • pp.725-734
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    • 2017
  • The main purpose of this study is to analyze runoff aggregation structure and energy expenditure pattern of Choyang creek basin within the framework of power law distribution. To this end geomorphologic factors of every point in the basin of interest, which define tractive force and stream power as well as drainage area, are extracted based on GIS, and their complementary cumulative distributions are graphically analyzed through fitting them to power law distribution. The results indicate that three distinct behavioral regimes are observed from the complementary cumulative distributions of three geomorphogic factors. Based on the parameter estimation of power law distribution by maximum likelihood drainage area and stream power can be judged as scale invariance factor without finite scale while tractive force as scale dependence factor with finite scale. Furthermore, it is judged that tractive force would not follow power law distribution because it shows limited complex system behaviors only within the small extent of scale. The exponent of power law distribution for drainage area obtained in this study by maximum likelihood is larger than the previous researches due to the difference of parameter estimation methodologies. And the exponent for stream power is smaller than the previous researches due to the scaling property of channel slope for the basin of interest.

Variation of Single Gas ($SF_6$, $N_2$, $O_2$, $CF_4$) Permeance through Hollow Fiber Polymeric Membranes Depending on Temperature and Pressure (중공사 고분자 분리막을 통한 단일기체($SF_6$, $N_2$, $O_2$, $CF_4$) 투과플럭스의 온도와 압력에 따른 변화특성)

  • Lee, Min-Woo;Lee, Soon-Jae;Kim, Han-Byul;Kim, Sung-Hyun;Lee, Sang-Hyup
    • Membrane Journal
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    • v.22 no.1
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    • pp.23-34
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    • 2012
  • In this study, we investigated the permeation property of single gases ($N_2$, $O_2$, $SF_6$, $CF_4$ through hollow fiber polymeric membrane (PSF, PC, PI) as a function of pressure and temperature to decide operating condition for $SF_6$ gas separation process. The results showed the gas permeation varied differentlydepending on the properties of gases and membrane. When permeance of each gases was represented as a function of temperature and pressure in 3 dimensional space, the surface of permeance was shown approximately flat. Thus, we established permeance models with forms of first-and second-order polynomial. These two models showed high goodness of fit. This indicates that the two polynomial models have enough applicability to predict the gas separation process.

Severity Analysis of the Pedestrian Crash Patterns Based on the Ordered Logit Model (Ordered Logit Model을 이용한 보행자 사고 심각도 요인 분석)

  • Choi, Jai-Sung;Kim, Sang-Youp;Hwang, Kyung-Sung;Baik, Seung-Yup
    • International Journal of Highway Engineering
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    • v.11 no.1
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    • pp.153-164
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    • 2009
  • This Paper presents the severity analysis result of the year 2006 national pedestrian crashes using the data base of 37,589 records prepared for the National Police Bureau. A set of attributing factors considered to affect pedestrian crash patterns were selected, and their contributing effects were investigated by applying the Ordered Logit Model. This model was selected because this model has been able to afford satisfactory results when the dependent variable involved ordered severity levels; fatal, injury, and property- damage-only in this investigation. The investigation has unveiled the followings; First, the pedestrian crash patterns were dependent upon human -drivel and pedestrian- characteristics including gender, age, and drinking conditions. Second, other contributing factors included vehicle, roadway geometric, weather, and hour of day characteristics. Third, seasonal effect was not contributive to crash patterns. Finally, the application of the Ordered Logit Model facilitated the ordered severity level analysis of the pedestrian crash data. This paper concludes that conventional wisdom on the pedestrian crash characteristics is largely truthful. However, this conclusion is limited only to the data used in this analysis, and further research is required for its generalization.

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VANET Privacy Assurance Architecture Design (VANET 프라이버시 보장 아키텍처 설계)

  • Park, Su-min;Hong, Man-pyo;Shon, Tae-shik;Kwak, Jin
    • Journal of Internet Computing and Services
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    • v.17 no.6
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    • pp.81-91
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    • 2016
  • VANET is one of the most developed technologies many people have considered a technology for the next generation. It basically utilizes the wireless technology and it can be used for measuring the speed of the vehicle, the location and even traffic control. With sharing those information, VANET can offer Cooperative ITS which can make a solution for a variety of traffic issues. In this way, safety for drivers, efficiency and mobility can be increased with VANET but data between vehicles or between vehicle and infrastructure are included with private information. Therefore alternatives are necessary to secure privacy. If there is no alternative for privacy, it can not only cause some problems about identification information but also it allows attackers to get location tracking and makes a target. Besides, people's lives or property can be dangerous because of sending wrong information or forgery. In addition to this, it is possible to be information stealing by attacker's impersonation or private information exposure through eavesdropping in communication environment. Therefore, in this paper we propose Privacy Assurance Architecture for VANET to ensure privacy from these threats.

A Database of Simple Sequence Repeat (SSR) Marker-Based DNA Profiles of Citrus and Related Cultivars and Germplasm (SSR Marker를 이용한 감귤속 품종 및 유전자원에 대한 DNA Profile Data Base 구축)

  • Hong, Jee-Hwa;Chae, Chi-Won;Choi, Keun-Jin;Kwon, Yong-Sham
    • Horticultural Science & Technology
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    • v.34 no.1
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    • pp.142-153
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    • 2016
  • The present study investigated identification of cultivars through phylogenetic analysis of 108 Citrus varieties and related cultivars using simple sequence repeat (SSR) markers. Two hundred three SSR primer pairs were used to detect polymorphic markers among 8 Citrus cultivars consisting of 4 mandarins, 1 orange, 1 tangor, 1 tangelo, and 1 pumelo. Eighteen SSR primer pairs were reproducible and showed highly polymorphic alleles. These markers were applied to assess genetic variations of the 108 varieties. Each marker detected 5-14 alleles, with an average of 9.28. The polymorphism information content varied from 0.417 to 0.791 with an average of 0.706. Cluster analysis with SSR markers resulted in 13 major groups reflecting cultivar types and pedigree information. Twelve orange cultivars in the $I-1^{st}$ sub-cluster and 23 mandarin cultivars in the $II-1^{st}$ sub-cluster, respectively, were not discriminated using the SSR markers. This could be due to narrow genetic backgrounds originated through bud mutation or nucellars seedlings. The SSR profile database of Citrus cultivars will be useful as a tool for protection of plant breeders' intellectual property rights in addition to assessing genetic diversity in Citrus cultivars and germplasms.

A Study on Analysis of Factors Affecting Technology Transfer Performance of Universities : An Approach to Different Types of Korean Universities (대학의 기술이전성과 영향요인 분석 : 대학의 유형별 접근)

  • Lee, Chang-Hak;Lee, Cheol-Gyu;Lee, Dong-Myung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.3936-3951
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    • 2011
  • This paper aims to analyze factors affecting technology transfer performance according to different types of Korean universities and to conduct the research for the channel and extent of impact between these factors, utilizing 5 - year data for the technology transfers of 110 universities based on the survey by National Research Foundation of Korea. According to the analysis, incentive for researchers is the most crucial factor in local universities and small & medium-sized private universities located in the capital area. And numerical value of intellectual property rights owned by university is the key factor in universities specializing in science & engineering / industry. Also, Big-sized universities are heavily affected by the number of full-time faculty. In case of private universities, government subsidy relating to patents is critical factor for technology transfer performance. The mean value of all variables is a lot higher in participant universities than non-participant ones in CK(Connect Korea) project. In summary, it is suggested that steady financial support provided by the government is required and that mutual cooperation for industry-university-government is also needed for the commercialization of the technologies held by universities.

A Study on Thermal Insulation Property and Thermal Crack Protection for Expanded Perlite Inorganic Composites (팽창진주암 무기복합재에서의 단열성능 및 열크랙 방지에 관한 연구)

  • Ahn, WonSool
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3286-3291
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    • 2014
  • A study on the crack protection and thermal insulation properties of the expanded perlite inorganic composites was performed. Mixed expanded perlite with a water glass was stabilized for 24 hrs at room temperature in the mold and, thereafter, converted into a massive foamed body through complete drying process at $150^{\circ}C$. Aluminum phosphate and micron size mica powder were used as a reaction accelerator and a stabilizer for thermal crack, respectively. Especially, use of mica exhibited a remarkable effect on the protection of thermal crack at higher temperature over $500^{\circ}C$, and thermal conductivity of the composites was enhanced with higher perlite contents, showing ca. 0.09 W/mK for the sample of 100/200/10/1.5 water glass/perlite/mica/Al phosphate by weight. A severe dimensional deformation of the composite materials was observed over $600^{\circ}C$, however, showing a temperature limitation for a practical application. The facts were considered as the results from the glass transition temperature of the water glass, of which main component is sodium silicate.

Analysis of Risk Classification on the Urban Flood Damage in Changwon city (창원시 용도지역별 침수 피해에 따른 위험등급화 분석)

  • Park, Ki-Yong;Jeong, Jin-Ho;Jeon, Won-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.685-693
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    • 2017
  • This study aims to effectively respond to urban local rainstorms by classifying the risk against flood damage for each use district. The risk classification is based on sensitivity analysis of the socio-economic damage caused by local rainstorms in Changwon city, Korea by a Fuzzy model using data, such as the districts that provide institutional bases for land use, land prices, which estimate the property values, and floor area ratios, which measures the density and areas of flood damage. The analysis result indicated that flood damage in five districts of Changwon (Masan happo-gu, Masan Hoewon-gu, Sungsan-gu, Euichang-gu, and Jinhae-gu) is highest in the order of commercial areas, residential areas, industrial areas, and forests, which was attributed to high land price and floor area ratio of commercial areas. On the other hand, specific analysis in Masan Hoewon-gu and Sungsan-gu was different from the previous result, indicating that the risk against flood damage may vary according to the districts depending on their local conditions. The analysis from this study can be applied to future urban planning and be used as a guideline to estimate the potential flood damage. Overall, this study is meaningful in that it proposes an effective management of land use as a new resolution to mitigate of urban flood damage within a broader perspective of climate change and urbanization.

Activation Property of Blast Furnace Slag by Calcined Alunite (하소(?燒) 명반석(明礬石)에 의(依)한 고로수쇄(高爐水碎)슬래그의 활성화(活性化) 특성(特性))

  • Kim, Hyung-Seok;Jo, Young-Do;Ahn, Ji-Whan;Kimura, Kunio;Han, Choon
    • Resources Recycling
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    • v.15 no.4 s.72
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    • pp.27-35
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    • 2006
  • In order to use alunite as an activator of blast furnace slag, we studied the hydration characteristics of the calcined alunite and the ground blast furnace slag. The alunite calcined at $650{\cire}C$ consists of KAl($KAl(SO_{4})_{2}$ and $Al_{2}O_{3}$. The calcined alunite reacts with $Ca(OH)_{2}$ and gypsum to form etrringite ($3CaO{\cdot}Al_{2}O_{3}{\cdot}3CaSO_{4}{\cdot}32H_{2}O$) as fellows:$2KAl(SO_{4})_{2}+2Al_{2}O_{3}+13Ca(OH)_{2}+5CaSO_{4}{\cdot}2H_{2}O+73H_{2}O{\rightarrow}3(3CaO{\cdot}Al_{2}O_{3}{\cdot}3CaSO_{4}{\cdot}32H_{2}O)+2KOH$. The $SO_{4}^{2-}$ ions from calcined alunite reacts with CaO in blast furnace slag to from gypsum, which reacts with CaO and $Al_{2}O_{3}$ to from ettringite in calcined alunite-blast furnace slag system. Therefore blast furnace slag can be activated by calcined alunite.

Classifying a Strength of Dependency between classes by using Software Metrics and Machine Learning in Object-Oriented System (기계학습과 품질 메트릭을 활용한 객체간 링크결합강도 분류에 관한 연구)

  • Jung, Sungkyun;Ahn, Jaegyoon;Yeu, Yunku;Park, Sanghyun
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.10
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    • pp.651-660
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    • 2013
  • Object oriented design brought up improvement of productivity and software quality by adopting some concepts such as inheritance and encapsulation. However, both the number of software's classes and object couplings are increasing as the software volume is becoming larger. The object coupling between classes is closely related with software complexity, and high complexity causes decreasing software quality. In order to solve the object coupling issue, IT-field researchers adopt a component based development and software quality metrics. The component based development requires explicit representation of dependencies between classes and the software quality metrics evaluates quality of software. As part of the research, we intend to gain a basic data that will be used on decomposing software. We focused on properties of the linkage between classes rather than previous studies evaluated and accumulated the qualities of individual classes. Our method exploits machine learning technique to analyze the properties of linkage and predict the strength of dependency between classes, as a new perspective on analyzing software property.