• Title/Summary/Keyword: natural selection

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Case Study on Optimization of Send-out Operation in Liquefied Natural Gas Receiving Terminal (LNG 터미널 송출 운전 최적화 사례 연구)

  • Park, Chansaem;Han, Chonghun
    • Korean Chemical Engineering Research
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    • v.53 no.2
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    • pp.150-155
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    • 2015
  • Recently, LNG receiving terminals have been widely constructed and expanded for an increase in LNG demand. Selection of the storage tank for send-out and estimation of send-out flow rate have significant influence to process operation and economics. In this study, a send-out flow rate of each storage tank is optimized in order to minimize the total BOG generation rate. Considering a size and characteristic of each storage tanks, BOG flow rates are estimated using a dynamic simulation with varying liquid levels in the tanks. The regression model is developed fitting BOG flow rates and tank liquid levels, which are boil off rate model to predict BOG flow rates with particular level data. The objective function and constraints including required total send-out flow rate and level limit in the tanks are formulated to optimize a send-out flow rate of each tank. This method for optimization of send-out operation is applied to the Incheon LNG receiving terminal considering two scenarios for various liquid levels and maximum and minimum required send-out flow rates. For maximum required send-out flow rate, this method achieves BOG reduction of 9% comparing with assumed conventional operation.

Last Ten Years of Korean Movie Industry through the Analysis on the Concentrations of Film Admission and Screening (영화 흥행 집중도와 상영 스크린 집중도로 살펴본 한국 영화산업 10년)

  • Kim, Jung-Ho
    • The Journal of the Korea Contents Association
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    • v.15 no.5
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    • pp.151-167
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    • 2015
  • Korean movie maintain their market share from the highest 59.7% to the lowest 42.1% during the last ten years in Korea. However, with the multiplex and wide release strategy, the monopolies of four major distribution companies and three multiplex chain, the polarization of Korean movie's Box Office performance is deepening. With Gini-Index, concentration of film admission has been deepened in intensity from 0.53 in 2004 to 0.85 in 2014. Using Thomas Piketty's method, Movie attendance proportion of Highest 10% of the box office ranking for 2014 sharply increased to 71.2% from 30.28% in 2004 and the lowest 50% of box office ranking dropped from 11.03% in 2004 to 0.08% in 2014. Concentrations of the number of Screen, Screening, the seating Capacity have the same analogy with the polarization of film admission. However, concentration of seating share has maintained a modest increase from 0.22 in 2004 to 0.38 in 2014. This analysis shows that polarization of Korean movie box office performance is not the sole result of Natural selection of market but the result of the monopolies of distribution companies and Multiplex chains.

Development and Application of Green Infrastructure Planning Framework for Improving Urban Water Cycle: Focused on Yeonje-Gu and Nam-Gu in Busan, Korea (도시물순환 개선을 위한 그린인프라 계획 프레임워크 개발 및 시범적용 - 부산시 연제구 및 남구를 대상으로 -)

  • Kang, JungEun;Lee, MoungJin;Koo, YouSeong;Cho, YeonHee
    • Journal of Environmental Policy
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    • v.13 no.3
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    • pp.43-73
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    • 2014
  • Cities in Korea have rapidly urbanized and they are not well prepared for natural disasters which have been increased by climate change. In particular, they often struggle with urban flooding. Recently, green infrastructure has been emphasized as a critical strategy for flood mitigation in developed countries due to its capability to infiltrate water into the ground, provide the ability to absorb and store rainfall, and contribute to mitigating floods. However, in Korea, green infrastructure planning only focuses on esthetic functions or accessibility, and does not think how other functions such as flood mitigation, can be effectively realized. Based on this, we address this critical gap by suggesting the new green infrastructure planning framework for improving urban water cycle and maximizing flood mitigation capacity. This framework includes flood vulnerability assessment for identifying flood risk area and deciding suitable locations for green infrastructure. We propose the use of the combination of frequency ratio model and GIS for flood vulnerability assessment. The framework also includes the selection process of green infrastructure practices under local conditions such as geography, flood experience and finance. Finally, we applied this planning framework to the case study area, namely YeonJe-gu an Nam-gu in Busan. We expect this framework will be incorporated into green infrastructure spatial planning to provide effective decision making process regarding location and design of green infrastructure.

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MARGINAL FIDELITY AND FRACTURE STRENGTH OF IPS EMPRESS $2^{(R)}$ CERAMIC CROWNS ACCORDING TO DIFFERENT CEMENT TYPES

  • Cho Hyun-Ok;Kang Dong-Wan
    • The Journal of Korean Academy of Prosthodontics
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    • v.40 no.6
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    • pp.545-559
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    • 2002
  • There has been increasing use of IPS Empress $2^{(R)}$ owing to easy fabrication method, high esthetics similar to natural teeth, good marginal accuracy, and sufficient fracture strength. However, in clinical application, although a luting agent and the tooth cementation bonding procedure influence the marginal accuracy and fracture strength restoration, there has been a controversy in the selection of proper luting agent. This study was to measure the marginal fidelites and fracture strength of IPS Empress crowns according to three cement types, Protec $cem^{(R)}$, Variolink $II^{(R)}$ and Panavia $21^{(R)}$. After construction of 12 experimental dies for each group, IPS Empress $2^{(R)}$ crowns were fabricated and luted the metal master die prepartion of the maxillary right premolar. Marginal gaps before cementation and after cementation were measured. Buccal incline on the functional cusp of specimens were loaded until the catastrophic failure and fracture strength was measured. The results of this study were as follows: 1. The range of gap was $34.04{\pm}4.84{\mu}m$ before cementation and $37.88{\pm}5.00{\mu}m$ after cementation, which showed significant difference by paired t-test (p<0.05). The difference in the results from marginal accuracy according to measuring point proved to be not statistically significant by two-way ANOVA test (p>0.05). 2. The difference in the results from marginal accuracy according to three cement types Proved that The Variolink $II^{(R)}$ cement group had the least gap, $35.43{\pm}5.03{\mu}m$, and showed superior marginal accuracy while there existed statistic significance in Protec $cem^{(R)}$ cement group, $39.06{\pm}4.41{\mu}m$ or Panavia $21^{(R)}$ cement group, $39.16{\pm}4.39{\mu}m$ by two-way ANOVA test & multiple range test (p<0.05). 3. The difference in the results from fractures strength testing according to three cement type groups proved to be statistically significant (p<0.05). The Variolink $II^{(R)}$ cement group shows highest fracture strength of $1257.33{\pm}226.77N$, Panavia $21^{(R)}$ cement group has $1098.08{\pm}138.45N$, and Protec $cem^{(R)}$ cement group represents the lowest fracture strength of $926.75{\pm}115.75N$. 4. Three different cement groups of different components showed acceptable marginal fidelity and fracture strength. It is concluded that IPS Empress $2^{(R)}$ crowns luted using Variolink $II^{(R)}$ cement group had stronger fracture strength and smaller marginal gap than the other cement groups. Although Variolink $II^{(R)}$ resin cement seemed acceptable to clinical applications in IPS Empress $2^{(R)}$ system, the IPS Empress $2^{(R)}$ system still requires long-term research due to the lack of data in clinical applications.

A Usability Testing on the Tablet PC-based Korean High-tech AAC Software (태블릿 PC 기반 한국형 하이테크 AAC 소프트웨어의 사용성 평가)

  • Lee, Heeyeon;Hong, Ki-Hyung
    • Journal of the HCI Society of Korea
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    • v.7 no.2
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    • pp.35-42
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    • 2012
  • The purpose of this study was to evaluate the usability of the tablet PC-based Korean high-tech AAC(Augmentative Alternative Communication System) software. In order to develop an AAC software which is appropriate to Korean cultural/linguistic contexts and communication needs of the users, we examined the necessity and ease of use for the communication functions that are required in native Korean communication, such as polite expressions, tense expressions, negative expressions, subject-verb auto-matching, and automatic sentence generation functions, using a scenario-based user testing. We also investigated the users' needs, preferences, and satisfaction for the tablet PC-based Korean high tech AAC using a semi-structured and open questionnaires. The participants of this study were 9 special education teachers, 6 speech therapists, and 6 parents whose children had communication disabilities. The results of the usability testing of the tablet PC-based Korean high-tech AAC software presented positive responses in general, by indicating overall scores of above 4 out of 5 except in tense and negative expressions. The necessity and ease of use in the tense and negative expressions were evaluated relatively low, and it might be related to the inconsistent interface with the polite expressions. In terms of the user interface(UI), there were users' needs for clear visual feedback in the symbol selection and display, consistent interface for all functions, more natural subject-verb auto-matching, and spacing in the text within symbols. The results of the usability testing and users' feedback might serve as a guideline to compensate and improve the function and UI of the existing AAC software.

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A Quantitative Study on How the Cheonghae Anti-piracy Unit influences the Occurrence of Maritime Piracy near Somalia (청해부대 파병(다국적 해군의 대(對)해적 작전)이 소말리아 인근 해적사건 발생에 미치는 영향에 관한 정량적연구)

  • Han, Jong-Hwan
    • Strategy21
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    • s.46
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    • pp.123-157
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    • 2020
  • This research focuses on one important type of non-traditional threat, maritime piracy, and tries to supplement previous research from the perspective of military power, especially naval power. When considering the elements of military power, naval power is a core independent variable to explain piracy incidents. Indeed, naval power can play a key role in solving piracy problems, since naval power is the only legitimate force to respond to piracy in the sea. It is natural that well equipped and trained naval power in the sea increases the probability of capturing pirates, which leads to increasing the costs of piracy and decreasing its occurrences. In addition, since naval combatant ships have more impressive weapons than those of pirate boats, just the presence of naval combatant ships could serve to deter piracy incidents in the sea. The main purpose of this research is finding the effectiveness of large multinational naval efforts to deter piracy incidents in Africa. With this research purpose, I analyze 771 piracy incidents that occurred in African states from 2009 to 2014. Furthermore, I include all 33 coastal states in Africa regardless of the experiences of piracy incidents in order to avoid selection bias, which is very common in quantitative-based piracy incidents research. The dependent variable of this research is frequency of maritime piracy incidents for a country-year and the independent variable is the number of multi-national naval warships that operate near Somalia. With this analysis, I find the large number of multi-state naval combatant ships are negatively related to piracy incidents. In other words, as a main means to counteract piracy incidents, multi-state naval combatant ships are conducive to reduce piracy incidents near Somalia, since it increases costs (being captured) of conducting piracy.

A study of the Characteristics of Community Design for Modern Industrial Heritage's Reproduction (근대산업유산 재생을 위한 커뮤니티디자인 특성 연구)

  • Jeong, Min-Joo;Lee, Chan
    • Korean Institute of Interior Design Journal
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    • v.23 no.4
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    • pp.157-168
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    • 2014
  • In buildings on the street, indiscriminate redevelopment are being made by overlooking the relationship with surrounding landscape to create their own unique meaning, due to industrialization progressed rapidly with human needs of longing for something constantly. Selection and methods of two plans, conservation and utilization should be required, considering heritage values on industrial buildings which are being lost and aged in this redevelopment higher. The attempt for the use of modern industrial heritage becomes a hot topic, and several experimental challenges are being made. However, there are rather many cases of causing industrial buildings' depreciation and one-size-fits-all reproduction performance as it applies other examples as standards by recognizing the reproduction of modern industrial heritage as one trend, not focusing on the trend of the times or paradigm, what the times want. To minimize these problems, we focus on how to utilize industrial buildings beyond the importance of industrial buildings' reproduction, considering the quality of local residents' life as well as the expected effect obtainable due to security of local identity and reproduction of buildings, focusing on the concept of community design that offers and forms a way of community life as the design of shares based on unspecified individuals' common life. Community design's core can be called to have diversity rather than undifferentiated unity by pursuing whole unification, since local residents become those who plan design and all people participate in it. In addition, community design achieves integration with other fields as an enlarged design area without limiting in an environmental area, by making indigenously natural characteristics combined with cultural factors in one context so that people may understand the flow of the place. The importance of effects acquired from modern industrial heritage's reproduction has well-known, and the attempt for utilizing aged heritage as a new value and a function has constantly been made. Now, it's time to focus on how long it lasts through this method, rather than modern industrial heritage's reproduction itself. There can be a significance in this study in proposing methodological solutions on modern industrial heritage's reproduction, not to cause depreciation of industrial buildings by recognizing contemporary trends and uniform regeneration performance, multifaceted research is needed for creative, effective development on modern industrial heritage which will occur constantly.

UA Tree-based Reduction of Speech DB in a Large Corpus-based Korean TTS (대용량 한국어 TTS의 결정트리기반 음성 DB 감축 방안)

  • Lee, Jung-Chul
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.7
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    • pp.91-98
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    • 2010
  • Large corpus-based concatenating Text-to-Speech (TTS) systems can generate natural synthetic speech without additional signal processing. Because the improvements in the natualness, personality, speaking style, emotions of synthetic speech need the increase of the size of speech DB, it is necessary to prune the redundant speech segments in a large speech segment DB. In this paper, we propose a new method to construct a segmental speech DB for the Korean TTS system based on a clustering algorithm to downsize the segmental speech DB. For the performance test, the synthetic speech was generated using the Korean TTS system which consists of the language processing module, prosody processing module, segment selection module, speech concatenation module, and segmental speech DB. And MOS test was executed with the a set of synthetic speech generated with 4 different segmental speech DBs. We constructed 4 different segmental speech DB by combining CM1(or CM2) tree clustering method and full DB (or reduced DB). Experimental results show that the proposed method can reduce the size of speech DB by 23% and get high MOS in the perception test. Therefore the proposed method can be applied to make a small sized TTS.

Pattern of Drugs & Poisons in Autopsy Cases in Korea for Recent Three Years (2007~2009) - Selection of Target Drugs for Systematic Toxicological Analysis - (최근 3년간 국내 변사체 중 약독물 검출 유형(2007~2009) - 약독물 검출 시스템 확립을 위한 목표 약물의 선별 -)

  • Kim, Eun-Mi;Kim, Ji-Hyun;Hong, Hyo-Jeong;Jeong, Su-Jin;In, Sang-Hwan;Rhee, Jong-Sook;Jung, Jin-Mi;Lee, Han-Sun;Lee, Sang-Ki
    • YAKHAK HOEJI
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    • v.54 no.5
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    • pp.341-347
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    • 2010
  • The majority of forensic autopsies in Korea are performed by the National Institute of Scientific Investigation (NISI), and the NISI has carried out about 4,000 cases annually. Total 4,578 autopsies were performed by NISI in 2009, among them 2,918 cases (64%) were carried out at main office of NISI in Seoul, which is in charge of Seoul, Incheon and Gyeonggi province. In this study we investigated pattern of drugs & poisons in autopsy cases for recent three years in Korea. Postmortem specimens (bloods, gastric contents, etc) from autopsy cases by main office of NISI during 2007~2009 were screened for drugs & poisons. Using laboratory information management system of NISI (iLIMS), the kinds of drugs & poisons and the frequency were investigated. As the results, 1,705 cases were negative to drugs & poisons, it occupied 58% of total 2,918 autopsy cases in 2009. During three years (2007~2009), the kinds of drugs & poisons detected in specimens were 206, 185 and 203, respectively, and top three drugs were atropine (anticholinergic), chlorpheniramine (antihistamine) and lidocaine (local anaesthetic/anti-arrythmic). These drugs were supposed to be used not so much for suicidal or homicidal purpose as for therapeutic purpose in hospital. Meanwhile cyanide showed the highest frequency of poisons during 2007~2009, and the frequency was 32 cases in 2009. In case of pesticides, poisoning by paraquat (herbicide, 17 cases) showed the highest frequency, and methomyl (insecticide, 9 cases) and glyphosate (herbicide, 7 cases) were followed. Finally we selected 62 drugs as target drugs for systematic toxicological analysis (STA) for Korea. Poisons such as pesticides, natural toxins, volatile compounds should be included for STA in further study.

Vegetation and flora of Hibiscus hamabo inhabited naturally in Soan Island

  • Ahn, Young-Hee;Chung, Kyu-Hwan;Park, Hee-Seung
    • Journal of Environmental Science International
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    • v.12 no.11
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    • pp.1181-1187
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    • 2003
  • Hibiscus hamabo, called "Hwang-geun", growing about 3m in height is a deciduous shrub or subtree of Malvaceae. Because the number of these species is very limited in the world, the Ministry of Environment has designated H. hamabo as a preserved plant. The Korea Forest Service also protects it strictly by law since H. hamabo is an out-of-the-way plant and possibly may be exterminated soon in Korea. Investigation for distribution and ecological characteristics of the habitat for H. hamabo was carried out on Soan Island. Two wild H. hamabo were found at the forest edge (equation omitted) along the sea coast located in the southern part of Soan Island and this was the first report in the Korean academic world. These two wild H. hamabos were growing in a naturally inhibited area. The diameters at the base were 12cm and 15cm. The Tree heights were 150cm and 210cm and the number of branches of each wild H. hamabo was 4 and 7. However, the present condition of these plants was not good. Environmental conditions of the naturally inhibited area of H. hamabo were very mild because it is located at the edge of the forest and is always sunny during the daytime since the slope of the inhibited area is facing South. The ground drained very well since the soil was made of gravels and sand. Because the percent of vegetation of the subtree layer where H. hamabo was growing was 40%, the cover degree and sociability of flex crenata trees and Eurya japonica were found to be high. In the naturally inhibited area of H. hamabo, a dominant value of Rubus parvifolius in the lower part of the herb layer was very high and many plants in Compositae, such as Artemisia princeps var. orientalis and Erigeron annuus, were also present. A dominant value of liana, such as Vitis thunbergii var. sinuata, Rosa multiflora, Clematis terniflora and Hedera rhombea, and Gramineae plants that rhizomes were well developed and aggressively propagated, such as Miscanthus sinensis var. purpurascens, Phragmites communis, Spodiopogon cotulifer and Oplismenus undulatifolius which were surveyed as high, too. These results imply that H. hamabo might be exterminated soon through a natural selection if the proper management of the naturally inhibited area of H. hamabo is not conducted continually.