• Title/Summary/Keyword: environmental variables

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Survey on the Hospice Care Needs of Hospice Volunteers (호스피스 자원봉사자의 호스피스 케어 요구도 분석)

  • Cho, Hyun;Kang, Hee-Sook;Kim, Jeoung-Hee
    • Journal of Hospice and Palliative Care
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    • v.5 no.2
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    • pp.155-162
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    • 2002
  • Purpose : The purpose of this study is to provide preliminary information on the hospice care needs of hospice volunteers. Methods : The sample of this study was obtained from those who completed the hospice volunteer education program in three different areas in Korea. This study was conducted by a self-administered questionnaire. The sample analyzed for this study contained 88 hospice volunteers. Frequency, percentage, mean, standard deviation, and logistic regression analysis were performed to produce the findings of this study. Results : The characteristics of the study sample were $40{\sim}49$ aged, middle class, christianity, married women with high school diplomas. They attended at the hospice center with less than 1 year experience. Majority of them had no family members who received a hospice care. The hospice care was strongly required in the field of information, particularly regarding their diseases and treatments. The identified hospice care needs were the prevention and treatment of gangrene in the field of physical needs, the maintenance of closer relationship with their doctors in the field of emotional needs, and the support of supporting medical insurance in the field of socioeconomic needs. The significant predictors were 'having hospice care taker among family members' in the field of the total hospice care needs and physical needs. Two predictable variables were found in the field of emotional needs. However, none were found to be a predictable variable in the field of information and socioeconomic needs. Conclusion : The findings or this study have a weekness of generalizability due to the sampling methodology used in this study. Thus, further research should be designed in relation to this topic with a probability sampling method.

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An Investigation of Reliability and Safety Factors in RC Flexural Members Designed by Current WSD Standard Code (현행(現行) 허용응력설계법(許容應力設計法)으로 설계(設計)되는 RC 휨부재(部材)의 신뢰성(信賴性)과 안전율(安全率) 고찰(考察))

  • Shin, Hyun Mook;Cho, Hyo Nam;Chung, Hwan Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.1 no.1
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    • pp.33-42
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    • 1981
  • Current standard code for R.C. design consists of two conventional design parts, so called WSD and USD, which are based on ACI 318-63 and 318-71 code provisions. The safety factors of our WSD and USD design criteria which are taken primarily from ACI 318-63 code are considered to be not appropriate compared to out country's design and construction practices. Furthermore, even the ACI safety factors are not determined from probabilistic study but merely from experiences and practices. This study investigates the safety level of R.C. flexural members designed by the current WSD safety provisions based on Second Moment Reliability theory, and proposes a rational but efficient way of determining the nominal safety factors and the associated flexural allowable stresses of steel bars and concretes in order to provide a consistent level of target reliability. Cornell's Mean First-Order Second Moment Method formulae by a log normal transformation of resistance and load output variables are adopted as the reliability analysis method for this study. The compressive allowable stress formulae are derived by a unique approach in which the balanced steel ratios of the resulting design are chosen to be the corresponding under-reinforced sections designed by strength design method with an optimum reinforcing ratio. The target reliability index for the safety provisions are considered to be ${\beta}=4$ that is well suited for our level of construction and design practices. From a series of numerical applications to investigate the safety and reliability of R.C. flexural members designed by current WSD code, it has been found that the design based on WSD provision results in uneconomical design because of unusual and inconsistent reliability. A rational set of reliability based safety factors and allowable stress of steel bars and concrete for flexural members is proposed by providing the appropriate target reliability ${\beta}=4$.

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The Statistical Identification of Airmass Characteristics during the Manna Loa Observatory Photochemistry Experiment (Mauna Loa (Hawaii)에서 관측된 대기질 특성의 통계적 분석)

  • Lee, Gang-Woong;Barry J. Huebert
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.E
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    • pp.332-342
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    • 1994
  • Hierarchical cluster and factor analyses were used to identify various influences on free tropospheric air samples at Mauna Loa Observatory in Hawaii during MLOPEX. The cluster analysis separated thirteen chemical and meteorological variables into three characteristic groups (1)clean air, (2)anthropogenically influenced air, (3)marine and volcanic influenced air. The cluster analysis results compared well with those of factor analysis. Six independent components were identified in factor analysis. We have related these components to (1)volcano influenced air, (2)stratosphere-like air, (3)boundary-layer air with recent anthropogenic influence, (4)photochemical haze, (5)marine boundary- layer air, and (6)modified marine tropospheric air. Excluding local influence, we could calculate the nighttime free tropospheric values for $O_3$(41$\pm$10 ppbv), HN $O_3$(94$\pm$45 pptv), N $O_3$$^{[-10]}$ (16$\pm$10 ppbv), S $O_4$$^{[-10]}$ (60$\pm$0 pptv), N $H_4$$^{+}$(71$\pm$6 pptv), N $a^{+}$(5$\pm$1 pptv), PAN(13$\pm$9 pptv), MeN $O_3$(3.5$\pm$1.5 pptv), 2-butyl N $O_3$(0.6$\pm$0.1 pptv), $H_2O$$_2$(1015$\pm$44 pptv), $C_2$C $l_4$(3.3$\pm$0.1 pptv), condensation nuclei(249$\pm$13c $m^{-3}$), and dew point(-8.5$\pm$5.3$^{\circ}C$) during this experiment..

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A Study on the Effect of Environmental Pollution on the Biomass Productivity of Paulownia coreana (환경오염(環境汚染)이 오동나무인공림(人工林)의 물질생산(物質生産)에 미치는 영향(影響)에 관한 연구(硏究))

  • Kim, Tae Wook;Lee, Kyong Jae;Park, In Hyeop
    • Journal of Korean Society of Forest Science
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    • v.58 no.1
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    • pp.8-16
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    • 1982
  • To study the comparison of aboveground biomass of paulownia coreana Uyeki of 6-year-old, located in Seongju of non-attacked forest and Ulsan of damaged forest by the air pollution were selected. Ten sample trees in Seongju district and seven trees in Ulsan selected taking account of DBH were measured for 16 trees in total within a $10{\times}10m$ experimental plot. The diagram of oven-dry weight distribution of stem, branch and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the two-variables, DBH and tree height, combined term were presented. IF the estimations are extended to a hectare area stand, it contains 47.49 tons of aboveground biomass in Seongju district and 19.05 tons of it in Ulsan. The annual net productions were 11.64 tons of above 2.29 kg/kg/yr in Ulsan and the efficiency of leaf to produce stem was 2.99kg/kg/yr in Seongju and 0.83kg/kg/yr in Ulsan.

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A Study for the Evaluation of Container Modules; The Technology of Korean Container Tree Production Model (한국형 컨테이너 조경수 생산기술로서 컨테이너 모듈의 성능 평가)

  • Jung, Yong-Jo;Lim, Byung-Eul;Oh, Jang-keun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.44 no.5
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    • pp.59-67
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    • 2016
  • In landscape design by public institutions, although the costs and species of landscape trees stipulated by the Korean Public Procurement Service(PPS) are generally adhered to, the PPS regulations about planting trees with well-developed rootlets are almost entirely neglected. This study aimed to evaluate the performance of buried container modules, which are a new technology and product in landscape production that is able to reduce the defect rate while complying with regulations. To this end, this study measured rootlet density, rootlet development length, rootlet survival rate on excavation, and impairments of tree growth for 3 months after root pruning, and compared these variables for the container modules with those for trees that underwent root pruning in bare ground, and those that were cultivated in a container above ground. The results were as follows: First, the rootlet density was 88% for the trees in container modules, which was very high. Trees that underwent standard root pruning in bare ground had a somewhat lower density of 64%. Meanwhile, the trees that were cultivated in pots above ground died, invalidating measurement. Second, in terms of rootlet development and rootlet survival rate, the trees in container modules showed a mean length of 10.4cm, and 100% survival rate, indicating that there was no rootlet damage caused by excavation. For the trees that only underwent root pruning in bare ground, the mean length was 25.6cm and the rootlet survival rate was only half that of the trees in container modules, at 56%, demonstrating considerable damage. Rootlet development did not occur at all in the trees grown in pots. Third, the trees in container modules and those that underwent root pruning in bare ground did not show any deaths during the root pruning process, or any impairments such as stunted leaf growth. Conversely, the trees grown in pots nearly all died, and severe impairments of tree growth were observed. As shown by the results above, when we evaluated the performance of buried container modules, they showed the most outstanding performance of the three models tested in this study. The container modules prevent defects by stimulating early rooting in environments that with poor conditions for growth, or in trees that are not suited to the summer environment Therefore, it is expected that they would be an optimal means by which to enable compliance with rules such as the regulation presented by the PPS.

Analysis of Research Trends in the Successful Establishment of Venture Companies: with Priority Given to Domestic Articles Between 1998 and 2014 (국내 벤처기업의 창업 성공에 관한 연구동향 분석: 메타분석을 활용하여)

  • Lee, Yong-hee;Hong, Kwang-pyo;Park, Su-hong
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.6
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    • pp.15-26
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    • 2015
  • The purpose of this study was to examine the area, theme and method of domestic articles on the successful establishment of venture companies, which were presented between 1998 and 2014, according to related basic classification criteria in an effort to shed light on the characteristics of these studies. It's basically meant to make a contribution to the development of research on the success of venture business and to be of practical use for the success of venture companies in our country. After related earlier studies were analyzed, 164 articles were collected, and 64 articles were selected from among them. The articles that were overlapped, not presented or not registered were excluded. The related studies had been conducted by different learned societies that were interested in the same research themes, and the studies were primarily led by the Korean Society of Business Venturing as of 2014, especially by Asia-Pacific Journal of Business Venturing and Entrepreneurship that was a journal published by this society. This society seemed to have taken the initiative in this field. There was a tendency that the related studies increased in number due to the shifts of modern industrial society and the changing policies of the government, as the number of the studies has been on the steady rise since 2012. In terms of method, quantitative research methods, especially descriptive studies, were prevailing. To step up the development of research into this field, a wide variety of research methods should be utilized in the future. As for the sphere of research, the characteristics of founders, strategic characteristics and environmental characteristics were mainly covered as the success factors of venture business. More diverse variables should be explored as well to make more advanced, extended research in the years to come. The findings of the study are expected to provide both theoretical and practical information on the establishment and success of venture business to make a contribution to the development of research.

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Optimum Design of Two Hinged Steel Arches with I Sectional Type (SUMT법(法)에 의(依)한 2골절(滑節) I형(形) 강재(鋼材) 아치의 최적설계(最適設計))

  • Jung, Young Chae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.3
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    • pp.65-79
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    • 1992
  • This study is concerned with the optimal design of two hinged steel arches with I cross sectional type and aimed at the exact analysis of the arches and the safe and economic design of structure. The analyzing method of arches which introduces the finite difference method considering the displacements of structure in analyzing process is used to eliminate the error of analysis and to determine the sectional force of structure. The optimizing problems of arches formulate with the objective functions and the constraints which take the sectional dimensions(B, D, $t_f$, $t_w$) as the design variables. The object functions are formulated as the total weight of arch and the constraints are derived by using the criteria with respect to the working stress, the minimum dimension of flange and web based on the part of steel bridge in the Korea standard code of road bridge and including the economic depth constraint of the I sectional type, the upper limit dimension of the depth of web and the lower limit dimension of the breadth of flange. The SUMT method using the modified Newton Raphson direction method is introduced to solve the formulated nonlinear programming problems which developed in this study and tested out throught the numerical examples. The developed optimal design programming of arch is tested out and examined throught the numerical examples for the various arches. And their results are compared and analyzed to examine the possibility of optimization, the applicablity, the convergency of this algorithm and with the results of numerical examples using the reference(30). The correlative equations between the optimal sectional areas and inertia moments are introduced from the various numerical optimal design results in this study.

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The Study on the Seasonal Variation of Microbial Community in Kyeonggi Bay, Korea 1. Bacteria and Heterotrophic nanoflagellates (경기만 수역에서 미세생물 군집의 계절적 변동 연구 I. 박테리아와 종속영양 미소 편모류)

  • 양은진;최중기;현정호
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.1
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    • pp.44-57
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    • 2003
  • Seasonal variations of bacterial abundance and production, heterotrophic nanoflagellate (HNF) abundance and HNF ingestion rates on bacteria using FLB together with environmental variables were investigated at intervals of a month in Kyeonggi Bay from December 1991 to November 1998. Bacterial abundance and production ranged from 0.38$\times$10$^{9}$ ~ 3.25$\times$10$^{9}$ cells 1$^{-1}$ (average 1.19$\pm$0.69$\times$10$^{9}$ cells 1$^{-1}$ ) and from 1.51 to 20.4 cells 1$^{-1}$ h$^{-1}$ (average 6.04$\pm$ 1.88$\times$10$^{6}$ cells 1$^{-1}$ h$^{-1}$ ), respectively. Bacterial abundance and production showed no differences at the high tide and low tide, and bacterial abundances were not different with depth, but bacterial production decreased with depth. Seasonal variation of bacterial abundance showed almost similar fluctuation pattern to those of DOC (dissolved organic carbon). HNF abundances ranged from 388 to 4,374 cells ml$^{-1}$ (average 1,344$\pm$130 cells ml$^{-1}$ ), were high in March, April, July and August. HNF abundance showed no difference between the high tide and low tide, and was not different with depth. The ingestion rates of HNF on bacteria were 1.0 to 6.3$\pm$10$^{6}$ bacteria 1$^{-1}$ h$^{-1}$ (average 3.12$\pm$0.55$\times$10$^{6}$ bacteria 1$^{-1}$ h$^{-1}$ ), resulting ingestion rates of HNF removed 19.4 to 141.4 %(average 62.3$\pm$12.0%) of bacterial production. Ingestion rates and grazing pressure of HNF on bacteria showed high correlation with HNF abundance. Although we cannot exactly discussion about seasonal variation of bacteria community in this study area where physical and chemical parameters were very complex, the results indicate that bacterial abundance and production were mainly controlled by resources supply as dissolved organic carbon and chlorophyll-a(bottom-up) except March which bacterial abundance and production uncoupled chlorophyll-a because of low dissolved organic carbon and low temperature, and were controlled by HNF grazing pressure(top-down) in the warm seasons except the winter.

Determination of Target Clean-up Level and Risk-Based Remediation Strategy (위해성에 근거한 정화목표 산정 및 복원전략 수립)

  • Ryu, Hye-Rim;Han, Joon-Kyoung;Nam, Kyoung-Phile
    • Journal of Soil and Groundwater Environment
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    • v.12 no.1
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    • pp.73-86
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    • 2007
  • Risk-based remediation strategy (RBRS) is a consistent decision-making process for the assessment and response to chemical release based on protecting human health and the environment. The decision-making process described integrates exposure and risk assessment practices with site assessment activities and remedial action selection to ensure that the chosen actions are protective of human health and the environment. The general sequences of events in Tier 1 is as follows: initial site assessment, development of conceptual site model with all exposure pathways, data collection on pollutants and receptors, and identification of risk-based screening level (RBSL). If site conditions do not meet RBSL, it needs further site-specific tier evaluation, Tier 2. In most cases, only limited number of exposure pathways, exposure scenarios, and chemicals of concern are considered the Tier 2 evaluation since many are eliminated from consideration during the Tier 1 evaluation. In spite of uncertainties due to the conservatism applied to risk calculations, limitation in site-specific data collections, and variables affecting the selection of target risk levels and exposure factors, RBRS provides us time- and cost-effectiveness of the remedial action. To ensure reliance of the results, the development team should consider land and resource use, cumulative risks, and additive effects. In addition, it is necessary to develop appropriate site assessment guideline and reliable toxicity assessment method, and to study on site-specific parameters and exposure parameters in Korea.

Complex Terrain and Ecological Heterogeneity (TERRECO): Evaluating Ecosystem Services in Production Versus water Quantity/quality in Mountainous Landscapes (산지복잡지형과 생태적 비균질성: 산지경관의 생산성과 수자원/수질에 관한 생태계 서비스 평가)

  • Kang, Sin-Kyu;Tenhunen, John
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.4
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    • pp.307-316
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    • 2010
  • Complex terrain refers to irregular surface properties of the earth that influence gradients in climate, lateral transfer of materials, landscape distribution in soils properties, habitat selection of organisms, and via human preferences, the patterning in development of land use. Complex terrain of mountainous areas represents ca. 20% of the Earth's terrestrial surface; and such regions provide fresh water to at least half of humankind. Most major river systems originate in such terrain, and their resources are often associated with socio-economic competition and political disputes. The goals of the TERRECO-IRTG focus on building a bridge between ecosystem understanding in complex terrain and spatial assessments of ecosystem performance with respect to derived ecosystem services. More specifically, a coordinated assessment framework will be developed from landscape to regional scale applications to quantify trade-offs and will be applied to determine how shifts in climate and land use in complex terrain influence naturally derived ecosystem services. Within the scope of TERRECO, the abiotic and biotic studies of water yield and quality, production and biodiversity, soil processing of materials and trace gas emissions in complex terrain are merged. There is a need to quantitatively understand 1) the ecosystem services derived in regions of complex terrain, 2) the process regulation occurred to maintain those services, and 3) the sensitivities defining thresholds critical in stability of these systems. The TERRECO-IRTG is dedicated to joint study of ecosystems in complex terrain from landscape to regional scales. Our objectives are to reveal the spatial patterns in driving variables of essential ecosystem processes involved in ecosystem services of complex terrain region and hence, to evaluate the resulting ecosystem services, and further to provide new tools for understanding and managing such areas.