• Title/Summary/Keyword: Metric

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Effects of Habitat Disturbance on Fish Community Structure in a Gravel-Bed Stream, Korea (자갈하천에서 서식처 교란이 어류 군집구조에 미치는 영향)

  • Kim, Seog Hyun;Lee, Wan-Ok;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.1 no.2
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    • pp.49-60
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    • 2014
  • Fish assemblages play an integral role in stream ecosystem and are influenced by stream environmental conditions and habitat disturbances. Fish community structures and habitat parameters of U.S. EPA rapid bio-assessment protocol were surveyed to investigate the effect of stream environment and habitat disturbance on fish communities at 13 study sites in the Gapyeong Stream, a typical gravel-bed stream. Principal component analysis (PCA) based on data from habitat assessment at each study site indicated that the study sites were differentiated by habitat parameters such as embeddedness, velocity/depth regime and sediment deposition, which were related with bed slope. A total of 46 species belonging to 12 families were collected in the Gapyeong Stream. A dominant species was Zacco koreanus, subdominant species was Z. platypus. Hierarchical cluster analysis based on species abundance classified fish communities into the three main groups along the stream longitudinal change. Non-metric multidimensional scaling (NMDS) portrayed that fish community structures were related to major habitat parameters, i.e., epifaunal substrate/available cover, embeddedness, velocity/depth regime, sediment deposition, channel alternation and frequency of riffles. These results suggested that fish community structures were primary affected by the longitudinal environmental changes, and those were modified by habitat disturbance in the Gapyeong Stream, a gravel-bed stream.

Ecological Characteristics and Chemical Gradients in Two Different Loach Populations-Misgurnus anguillicaudatus and Koreocobitis rotundicaudata (미꾸리(Misgurnus anguillicaudatus)와 새코미꾸리 (Koreocobitis rotundicaudata) 개체군의 생태지표 특성 및 이.화학적 수질구배 분석)

  • Shin, Eun Ju;Choi, Ji-Woong;An, Kwang-Guk
    • Korean Journal of Environmental Biology
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    • v.31 no.4
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    • pp.419-428
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    • 2013
  • The objectives of this research were to determine ecological characteristics and chemical gradients in two different loach populations-Misgurnus anguillicaudatus ($M_a$) and Koreocobitis rotundicaudata ($K_r$). Eight chemical parameters were compared to test the chemical preferences between the two species. The population of Kr occurred more in better water quality, compared to the $M_a$-population. The $M_a$-population co-occurred more with tolerant species (TS) and omnivores, whereas the $K_r$-population co-occurred more with sensitive species (SS) and insectivores. The differences in the tolerance and trophic composition matched well with the result of stream health assessment, based on the multi-metric model of Index of Biological Integrity (IBI). The IBI value in habitat with the $M_a$-population was "19.6" (range: 8~40) indicating a fair condition, and the IBI values of $K_r$-population was 29.4 (range: 12~40) indicating good condition. Similar results were found in physical habitat health analysis (QHEI). Overall, data analysis showed that the $M_a$-population belong to the tolerant species and $K_r$-population belong to sensitive species in the tolerance classification.

A Study on the Evaluation of Service Quality Index for International Airport Using MCJ (MCJ를 이용한 공항서비스 품질지수 평가에 관한 연구)

  • Lee, Seung-Chang;Lee, Gang-Seok
    • Journal of Korean Society of Transportation
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    • v.23 no.1
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    • pp.45-54
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    • 2005
  • The main purpose of this study is located at developing Ominibus Monitoring System(OMS) for the purpose of the internal management, which enable to establish job standards, find out matters to be improved, and appreciate for its treatment in a systematic way. It is through developing subjective or objective estimation tool with use of importance, perceived level, and complex index at international airport by each principal service items, The direction of this study came towards for the purpose of developing a metric analysis tool, utilizing the Quantitative Secondary Data, Analysing Perceived Data through airport user surveys, systemizing the data collection-input-analysis process, making data image according to the graph of results, planning service encounter and endowing control attribution, and ensuring competitiveness at the minimal international standards. It is much important to set up a pre-investigation plan on the base of existent foreign literature and actual inspection to international airport. Two tasks have been executed together on the base of this pre-investigation; one is developing subjective estimation standards for departing party, entering party, and airport residence and the other is developing objective standards as complementary methods. The study has processed for the monitoring services at airports regularly and irregularly through developing software system for operating standards after ensuring credibility and feasibility of estimation standards with substantial and statistical way.

Evaluation of Effective Dose and Exposure Levels of Radon in Office and Plant Buildings (일부 제조업 사업장의 사무 및 공장동에서의 라돈농도 수준 및 유효선량 평가)

  • Chung, Eun Kyo;Kim, Ki Woong
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.27 no.1
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    • pp.38-45
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    • 2017
  • Objectives: Radon may be second only to smoking as a cause of lung cancer. Radon is a colorless, tasteless radioactive gas that is formed via the radioactive decay of radium. Therefore, radon levels can build up based on the amount of radium contained in construction materials such as phospho-gypsum board or when ventilation rates are low. This study provides our findings from evaluation of radon gas at facilities and offices in an industrial complex. Methods: We evaluated the office rooms and processes of 12 manufacturing factories from May 14, 2014 to September 23, 2014. Short-term data were measured by using real-time monitoring detectors(Model 1030, Sun Nuclear Co., USA) indoors in the office buildings. The radon measurements were recorded at 30-minute intervals over approximately 48 hours. The limit of detection of this instrument is $3.7Bq/m^3$. Also, long-term data were measured by using ${\alpha}-track$ radon detectors(${\alpha}-track$, Rn-tech Co., Korea) in the office and factory buildings. Our detectors were exposed for over 90 days, resulting in a minimum detectable concentration of $7.4Bq/m^3$. Detectors were placed 150-220 cm above the floor. Results: Radon concentrations averaged $20.6{\pm}17.0Bq/m^3$($3.7-115.8Bq/m^3$) in the overall area. The monthly mean concentration of radon by building materials were in the order of gypsum>concrete>cement. Radon concentrations were measured using ${\alpha}-track$ in parallel with direct-reading radon detectors and the two metric methods for radon monitoring were compared. A t-test for the two sampling methods showed that there is no difference between the average radon concentrations(p<0.05). Most of the office buildings did not have central air-conditioning, but several rooms had window- or ceiling-mounted units. Employees could also open windows. The first, second and third floors were used mainly for office work. Conclusions: Radon levels measured during this assessment in the office rooms of buildings and processes in factories were well below the ICRP reference level of $1,000Bq/m^3$ for workplaces and also below the lower USEPA residential guideline of $148Bq/m^3$. The range of indoor annual effective dose due to radon exposure for workers working in the office and factory buildings was 0.01 to 1.45 mSv/yr. Construction materials such as phospho-gypsum board, concrete and cement were the main emission sources for workers' exposure.

The Development of a Sampling Instrument for Aquatic Organisms in Rice Paddy Fields: Submerged Funnel Traps with Attractants (논 생태계 서식 수서생물 채집 도구 개발: 유인제를 사용한 수중트랩)

  • Yoon, Sung-Soo;Kim, Myung-Hyun;Choi, Soon-Kun;Eo, Jinu;Kwon, Soon-Ik;Song, Young-Ju
    • Korean Journal of Environmental Biology
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    • v.35 no.4
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    • pp.640-647
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    • 2017
  • The need for an efficient sampling technique to collect aquatic organisms has risen with the increase of interest in rice paddy fields, which have been recognized as important ecosystems supporting biodiversity. In the present study, a submerged funnel trap used with the assistance of attracting agents (fish meal and chemical light) was designed as an easy, objective and quantitative tool for collecting aquatic organisms in the rice paddy fields. The preference for collecting aquatic organisms as a means for attracting agents was analyzed using a generalized linear mixed model. Also, based on the data of previous research, we compared the community composition of the aquatic macroinvertebrates, which were collected using the quadrat method, and newly designed submerged funnel traps, by analyzing non-metric multidimensional scaling. The results showed that the catching efficiency of 18 of the total 65 taxa was affected by the attracting agents. 12 taxa including Pomacea canaliculata, Hippeutis cantori, Austropeplea ollula, Erpobdella lineata, Ostracoda spp. Branchinella kugenumaensis, Hydaticus grammicus, Rhantus pulverosus, Chironomidae spp., Rana nigromaculata, Cobitidae spp. etc., favored fish meal and 6 taxa including Ischnura asiatica, Coenagrionidae spp. Sternolophus rufipes etc., were attracted by chemical light. The submerged funnel trap used as a measurement tool for biodiversity was less applicable than the quadrat method; however, it was more effective for the selective collection of specific taxa. We expect that this newly designed trap can be a simple and quantitative method for collecting aquatic organisms, and could be used for long term and extensive surveys in rice paddy fields in the future.

Measurement of Global Nursing Research Output: A Bibliometric Study (1996-2015)

  • Singh, Shivendra;Pandita, Ramesh
    • Journal of Information Science Theory and Practice
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    • v.6 no.1
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    • pp.31-44
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    • 2018
  • Purpose: This study aims to examine the research output in the field of nursing at the global level during the last two decades, viz., for the period 1996-2015, with special reference to India. Some of the aspects examined include the research growth in nursing literature during the period of study, leading nursing research countries at the regional and global level, and citation analysis. Scope and Methodology: This study is global in nature, but emphasis has also been laid on India's research contribution in nursing at the global level. Aspects like regional contribution to the nursing research output have also been assessed. This study is purely based on secondary data retrieved from SCImago Journal and Country Rankings. The figures in the study are based on one particular database and are not exhaustive; hence they simply reflect a trend in nursing research at the global level. Findings: During the period 1996 through 2015, a total of 550,490 research articles were published across the world by 212 nation states at an average of 2,596 articles from each individual country. On average, during the period of study, the number of nursing research publications grew at the rate of 7.36% each year. North America has emerged as one of the leading nursing research continents of the world by publishing 218,614 research articles, constituting 39.71% of the global nursing research output. The U.S. and U.K. are the world's two leading nursing research countries, which contributed 193,819 and 61,730 research articles respectively, comprising a 35.21% and 11.21% share of global nursing research output. India and China, apart from being the two fastest growing nursing research countries, have the potential to meet the global human resource demand in the field of nursing, given the skilled and trained human resource both these countries possess in nursing. Social Implication: There is always a need to share working knowledge in some professions and nursing is one of them. There cannot be a better medium than linking practice with theory through the research medium. Metric studies in turn help to get a better idea about the amount of work done in any given field at the national and international level, thus identifying the need thereof to improve upon those areas where there is research lag.

A Quality System for Evaluating Reusability of Core Assets in Product Line Engineering (프로덕트 라인 공학의 핵심자산 재사용성 평가를 위한 품질시스템)

  • Oh Sang-Hun;Her Jin-Sun;Kim Ji-Hyeok;Rhew Sung-Yul;Kim Soo-Dong
    • Journal of KIISE:Software and Applications
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    • v.33 no.3
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    • pp.277-288
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    • 2006
  • Product line engineering (PLE) is a new effective approach to software reuse, where applications are generated by instantiating a core asset which is a large-grained reuse unit. Hence, a core asset is a key element of PLE, and therefore the reusability of the core asset largely determines the success of PLE projects. A tore asset is a reusable part not a whole system, and supports not only variable functions but also common functions. However, there are limitations to evaluate reusability of core asset that has these unique characteristics. This paper proposes a comprehensive quality system for evaluating the reusability of core assets, based on ISO/IEC 9126. We first identify the key characteristics of core assets, and derive the set of quality attributes that characterizes the reusability of core assets. finally, we define metrics for each quality attribute. In addition, we provide guidelines for applying the metrics and perform a case study based on rental product line. Using the proposed quality system, reusability of core assets can be more effectively and correctly evaluated.

Practical Quality Model for Measuring Service Performance in SOA (SOA 서비스 성능 측정을 위한 실용적 품질모델)

  • Oh, Sang-Hun;Choi, Si-Won;Kim, Soo-Dong
    • The KIPS Transactions:PartD
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    • v.15D no.2
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    • pp.235-246
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    • 2008
  • Service-Oriented Architecture (SOA) is emerging as an effective approach for developing applications by dynamically discovering and composing reusable services. Generally, the benefits of SOA are known as low-development cost, high agility, high scalability, business level reuse, etc. However, a representative problem for widely applying SOA is the performance problem. This is caused by the nature of SOA such as service deployment and execution in distributed environment, heterogeneity of service platforms, use of a standard message format, etc. Therefore, performance problem has to be overcome to effectively apply SOA, and service performance has to be measured precisely to analyze where and why the problem has occurred. Prerequisite for this is a definition of a quality model to effectively measure service performance. However, current works on service performance lacks in defining a practical and precise quality model for measuring performance which adequately addresses the execution environment and features of SOA. Hence, in this paper, we define a quality model which includes a set of practical metrics for measuring service performance and an effective technique to measure the value of the proposed metrics. In addition, we apply the metrics for Hotel Reservation Service System (HRSS) to show the practicability and usefulness of the proposed metrics.

Monitoring of Commercial Cephalopod Products Sold on the South Korea Market using DNA Barcode Information (DNA 바코드를 이용한 국내 유통 두족류 제품의 원재료 모니터링 연구)

  • Yu, Yeon-Cheol;Hong, Yewon;Kim, Jung Ju;Kim, Hyung Soo;Kang, Tae Sun
    • Journal of Food Hygiene and Safety
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    • v.34 no.5
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    • pp.502-507
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    • 2019
  • Cephalopods are one of the most important fishery resources in the world because of their desirable taste and nutritional value. In south Korea, one of the countries in which a large amount of seafood is consumed, cephalopods (e.g., octopus, squid, and cuttlefish) have an annual consumption rate of over 400,000 metric tons. In this study, octopus and squid products (n=28) sold on the market were monitored by analyzing sequences of DNA barcode markers (cytochrome c oxidase subunit I and 16S ribosomal RNA genes). For species identification, the NCBI BLAST database was screened with the sequences and analyzed as a query. In this BLAST search, twelve squid products showed 99-100% sequence identity to Dosidicus gigas (n=3) and Todarodes pacificus (n=9). In the case of the other 16 products that were declared using octopus as raw materials on the labels, six products were identified as Cistopus taiwanicus (n=1), Amphioctopus marginatus (n=1), Scaeurgus unicirrhus (n=1), and Dosidicus gigas (n=3). Monitoring results indicated that a significant percentage (37.5%) of mislabeling was present in octopus products sold on the South Korean market.

Reliable multi-hop communication for structural health monitoring

  • Nagayama, Tomonori;Moinzadeh, Parya;Mechitov, Kirill;Ushita, Mitsushi;Makihata, Noritoshi;Ieiri, Masataka;Agha, Gul;Spencer, Billie F. Jr.;Fujino, Yozo;Seo, Ju-Won
    • Smart Structures and Systems
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    • v.6 no.5_6
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    • pp.481-504
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    • 2010
  • Wireless smart sensor networks (WSSNs) have been proposed by a number of researchers to evaluate the current condition of civil infrastructure, offering improved understanding of dynamic response through dense instrumentation. As focus moves from laboratory testing to full-scale implementation, the need for multi-hop communication to address issues associated with the large size of civil infrastructure and their limited radio power has become apparent. Multi-hop communication protocols allow sensors to cooperate to reliably deliver data between nodes outside of direct communication range. However, application specific requirements, such as high sampling rates, vast amounts of data to be collected, precise internodal synchronization, and reliable communication, are quite challenging to achieve with generic multi-hop communication protocols. This paper proposes two complementary reliable multi-hop communication solutions for monitoring of civil infrastructure. In the first approach, termed herein General Purpose Multi-hop (GPMH), the wide variety of communication patterns involved in structural health monitoring, particularly in decentralized implementations, are acknowledged to develop a flexible and adaptable any-to-any communication protocol. In the second approach, termed herein Single-Sink Multi-hop (SSMH), an efficient many-to-one protocol utilizing all available RF channels is designed to minimize the time required to collect the large amounts of data generated by dense arrays of sensor nodes. Both protocols adopt the Ad-hoc On-demand Distance Vector (AODV) routing protocol, which provides any-to-any routing and multi-cast capability, and supports a broad range of communication patterns. The proposed implementations refine the routing metric by considering the stability of links, exclude functionality unnecessary in mostly-static WSSNs, and integrate a reliable communication layer with the AODV protocol. These customizations have resulted in robust realizations of multi-hop reliable communication that meet the demands of structural health monitoring.