• Title/Summary/Keyword: 안정성 평가

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Techniques for Acquisition of Moving Object Location in LBS (위치기반 서비스(LBS)를 위한 이동체 위치획득 기법)

  • Min, Gyeong-Uk;Jo, Dae-Su
    • The KIPS Transactions:PartD
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    • v.10D no.6
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    • pp.885-896
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    • 2003
  • The typws of service using location Information are being various and extending their domain as wireless internet tochnology is developing and its application par is widespread, so it is prospected that LBS(Location-Based Services) will be killer application in wireless internet services. This location information is basic and high value-added information, and this information services make prior GIS(Geographic Information System) to be useful to anybody. The acquisition of this location information from moving object is very important part in LBS. Also the interfacing of acquisition of moving object between MODB and telecommunication network is being very important function in LBS. After this, when LBS are familiar to everybody, we can predict that LBS system load is so heavy for the acquisition of so many subscribers and vehicles. That is to say, LBS platform performance is fallen off because of overhead increment of acquiring moving object between MODB and wireless telecommunication network. So, to make stable of LBS platform, in this MODB system, acquisition of moving object location par as reducing the number of acquisition of unneccessary moving object location. We study problems in acquiring a huge number of moving objects location and design some acquisition model using past moving patternof each object to reduce telecommunication overhead. And after implementation these models, we estimate performance of each model.

SURFACE HARDNESS OF THE DENTAL COMPOSITE CURED BY LIGHT THAT PENETRATE TOOTH STRUCTURE ACCORDING TO THICKNESS OF TOOTH STRUCTURE, LIGHT INTENSITY AND CURING TIME (치질을 투과한 조사광에 의한 복합레진 중합시 치질의 두께, 광세기 및 조사 시간이 복합레진의 표면 경도에 미치는 영향)

  • Cho, Soo-Kyung;Kim, Dong-Jun;Hwang, Yun-Chan;Oh, Won-Mann;Hwang, In-Nam
    • Restorative Dentistry and Endodontics
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    • v.30 no.2
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    • pp.128-137
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    • 2005
  • In this study we measured the amount of light energy that was projected through the tooth material and analyzed the degree of polymerization by measuring the surface hardness of composites. For polymerization, Optilux 501 (Demetron, USA) with two types of light guide was used: a 12 mm diameter light guide with 840 nW/$cm^2$ light intensity and a 7 mm diameter turbo light guide with 1100 nW/$cm^2$. Specimens were divided into three groups according to thickness of penetrating tooth (1 mm, 2 mm, 0 mm). Each group was further divided into four subgroups according to type of light guide and curing time (20 seconds, 40 seconds). Vickers' hardness was measured by using a microhardness tester. In 0 mm and 1 mm penetrating tooth group, which were polymerized by a turbo light guide for 40 seconds, showed the highest hardness values. The specimens from 2 mm penetrating tooth group, which were polymerized for 20 seconds, demonstrated the lowest hardness regardless of the types of light guides (p < 0.05). The results of this study suggest that, when projecting tooth material over a specified thickness, the increase of polymerization will be limited even if light intensity or curing time is increased.

Strategies about Optimal Measurement Matrix of Environment Factors Inside Plastic Greenhouse (플라스틱온실 내부 환경 인자 다중센서 설치 위치 최적화 전략)

  • Lee, JungKyu;Kang, DongHyun;Oh, SangHoon;Lee, DongHoon
    • Journal of Bio-Environment Control
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    • v.29 no.2
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    • pp.161-170
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    • 2020
  • There is systematic spatial variations in environmental properties due to sensitive reaction to external conditions at plastic greenhouse occupied 99.2% of domestic agricultural facilities. In order to construct 3 dimensional distribution of temperature, relative humidity, CO2 and illuminance, measurement matrix as 3 by 3 by 5 in direction of width, height and length, respectively, dividing indoor space of greenhouse was designed and tested at experimental site. Linear regression analysis was conducted to evaluate optimal estimation method in terms with horizontal and vertical variations. Even though sole measurement point for temperature and relative humidity could be feasible to assess indoor condition, multiple measurement matrix is inevitably required to improve spatial precision at certain time domain such as period of sunrise and sunset. In case with CO2, multiple measurement matrix could not successfully improve the spatial predictability during a whole experimental period. In case with illuminance, prediction performance was getting smaller after a time period of sunrise due to systematic interference such as indoor structure. Thus, multiple sensing methodology was proposed in direction of length at higher height than growing bed, which could compensate estimation error in spatial domain. Appropriate measurement matrix could be constructed considering the transition of stability in indoor environmental properties due to external variations. As a result, optimal measurement matrix should be carefully designed considering flexibility of construction relevant with the type of property, indoor structure, the purpose of crop and the period of growth. For an instance, partial cooling and heating system to save a consumption of energy supplement could be successfully accomplished by the deployment of multiple measurement matrix.

A Study on Economic Value of Daegu Arboretum based on Contingent Valuation Methods (가상가치평가법을 이용한 대구수목원의 경제적 가치평가)

  • Kang, Kee-Rae;Lee, Kee-Cheol;Lee, Hyun-Taek;Ryu, Byong-Ro;Kim, Dong-Pil
    • Korean Journal of Environment and Ecology
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    • v.25 no.5
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    • pp.787-798
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    • 2011
  • An arboretum is defined as a collection of facilities that conserve plant species by surveying, collecting, and proliferating and preserving the plants in nature, perform diverse researches on plants and display the plants in exhibition spaces or outdoors as well as provide the public with educational programs and refreshment spaces according to the laws concerned. The public, however, recognizes the exhibition and education functions on plants of arboretum more importantly compared with the roles to survey, collect, and proliferate plants as regulated by the laws. In particular, arboretum plays a role to offer a pivotal educational place in urban area where the public can obtain an hands-on experience and understanding on a wide range of plant species and natural environment. The study aims to estimate the non market environmental values of Daegu Arboretum operated by Daegu Metropolitan City government by using the Contingent Valuation Methods (CVM), which yields the current monetary estimates for the arboretum. The value estimation was undertaken by using the Double-Bound Dichotomous Choice (DBDC) method, and each estimated value was derived from respective functions based on a logit distribution known to include relatively stable estimates according to the shape of the distribution. Considering the statistical fitness test results, the author estimated the amounts of the Willingness To Pay (WTP) such as mean WTP of 12,718 KRW, median WTP of 11,033 KRW, and truncated mean WTP of 11,468 KRW, which represented the annual recreational values per a person visiting Daegu Arboretum respectively. The analysis showed that Daegu Arboretum created the annual environmental values which were estimated to be approximately 16 to 19 billion KRW. The study also has an implication that the valuation method for the environment of Daegu Arboretum may be effectively applied for estimating the values of other types of environmental goods by altering the locations or goods to be analyzed.

Evaluation of Removal Efficiencies of Heavy Metals Using Brown Seaweed Biosorbent Under Different Biosorption Systems (폐미역을 이용한 생물흡착 시스템별 중금속 제거 효율 평가)

  • Choi, Ik-Won;Seo, Dong-Cheol;Kim, Sung-Un;Kang, Se-Won;Lee, Jun-Bae;Lim, Byung-Jin;Kang, Seok-Jin;Jeon, Weon-Tai;Heo, Jong-Soo;Cho, Ju-Sik
    • Korean Journal of Environmental Agriculture
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    • v.30 no.3
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    • pp.310-315
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    • 2011
  • BACKGROUND: Heavy-metal pollution represents an important environmental problem due to the toxic effects of metals, and their accumulation throughout the food chain leads to serious ecological and health problems. METHODS AND RESULTS: Optimum conditions in continuous-flow stirred tank reactor (CSTR) and packedbed column contactor (PBCC) using brown seaweed biosorbent were investigated. Under optimum conditions from both lab-scale biosorbent systems, removal efficiency of copper (Cu) in a large-scale PBCC system was investigated. Removal capacity of Cu using brown seaweed biosorbent in a lab-scale CSTR system was higher than that in a lab-scale PBCC system. On the other hand, over 48 L/day of flow rate in Cu solution, removal efficiency of Cu in a lab-scale PBCC system was higher than that in a lab-scale CSTR system. Optimum flow rate of Cu was 24 L/day, optimum Cu solution concentration was 100 mg/L. Removal capacity of Cu at different stages was higher in the order of double column biosorption system > single column biosorption system. Under different heavy metals, removal capacities of heavy metal were higher in the order of Pb > Cr > Ni > Mn ${\geq}$ Cu ${\geq}$ Cd ${\fallingdotseq}$ Zn ${\geq}$ Co. Removal capacity of Cu was 138 L in a large-scale PBCC system. Removal capacity of Cu a large-scale PBCC system was similar with in a lab-scale PBCC system. CONCLUSION(s): Therefore, PBCC system using brown seaweed biosorbent was suitable for treating heavy metal wastewater.

Compilation of Books on Military Arts and Science and Ideology of Military Science in the early Joseon Dynasty (조선(朝鮮) 초기(初期)의 병서(兵書) 편찬(編纂)과 병학(兵學) 사상(思想))

  • Yun, Muhak
    • (The)Study of the Eastern Classic
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    • no.49
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    • pp.325-355
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    • 2012
  • This research aims to generalize the thoughts of military science of the intellectuals through the books on military arts and science, which were published in the early Joseon Dynasty. In the early Joseon dynasty, it was in a position to establish the foundation in the new monarch internally, and, at the same time, to overcome foreign powers on both northern and southern borders externally. Thus, the books on military arts and science should have to be published under a premise of such situations. Accordingly, the books on military arts and science of those days took account of political stability having reflected the activities not only as the founder of Joseon but also as the military officer in the late Goryeo along with the books' own purpose to found military arts and sciences. The books on military arts and science that published in the early Joseon Dynasty were written mostly based on Chinese military books and its annotations, except some descriptions of the history of war. However, the intellectuals at that time endeavored to redefine military arts and science from the perspective of Confucianism having evaluated Chinese military science books that were biased to boost Machiavellian tactics. As a result of this, the geographical distinctions between China and Korea were the start of an argument for the military arts and science. There were also disputes over the relationships between the military science and the Yin-Yang School, and between the military science and Confucian school. Organizing our country's own history of war for the first time in the early Joseon Dynasty is worth for putting a high evaluation. However, it cannot help but to point out the limits of the books that there are noticeable descriptions about the factors related to toadyism, and that there are no descriptions about the wars against Japanese raiders. The books on military arts and science in the early Joseon Dynasty put emphasis on the commander's leadership that should be good at both literary and martial arts, as well as the harmony in military-to-military relations. After all, the intellectuals in the early Joseon Dynasty had linked the military arts and science to the sages of Confucian school under a premise that scholarship is to be used in combination with martial arts. And, as the nexus between the two, they noted the items of virtue, such as humaneness and righteousness (仁義); ritual and music (禮樂); loyalty and filial piety (忠孝); three fundamental principles (三綱); five moral disciplines (五倫). It can be said that this point is the typical features of the military arts and science in the early Joseon Dynasty, which cannot be found in Chinese military classics.

Vascular Plant Diversity and Vegetation of Samusan Mt. in Jecheon-si, Korean Peninsula (사무산(제천시)의 식물다양성과 식생)

  • Kim, Jung-Hyun;Kim, Jin-Seok;Nam, Gi-Heum;Jung, Eun-Hee;Lee, Kyeong-Ui;Hwang, Yo-Seob
    • Korean Journal of Plant Resources
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    • v.31 no.4
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    • pp.396-418
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    • 2018
  • This study was carried out to investigate the flora and the vegetation of Samusan mountain on Jecheon-si, located in the middle part of the Korean peninsula. The vascular plants which were collected in 9 times from June 2014 to October 2015 were identified as 502 taxa in total, including 102 families, 314 genera, 445 species, 6 subspecies, 49 varieties, 1 form and 1 hybrid. The largest families were as follows; Asteraceae (70 taxa), Poaceae (52 taxa), Rosaceae (30 taxa), Fabaceae (28 taxa), and Cyperaceae (20 taxa). Of them, Korean endemic plants numbered 10 taxa, and vascular plants listed in the red data according to the International Union for Conservation of Nature (IUCN) numbered 14 taxa. The floristic regional indicator plants found in this area were 61 taxa in total. Among them, 5 taxa revealed the floristic grade V, 11 for floristic grade IV, 14 for floristic grade III, 10 for floristic grade II, and 21 for floristic grade I. The alien plants were identified as 43 taxa and the percentage of naturalized index (NI) was 8.6%, and urbanization index (UI) was 13.4%, respectively. Samples of the forest vegetation on the Samusan Mt. were mainly classified as Pinus densiflora, Quercus variabilis, Q. acutissima, Q. mongolica, Zelkova serrata and Robinia pseudoacacia forest. The vertical structures of the forest were stable and the DBH-Class analyses showed that the dominant tree species would be maintained. In the surveyed areas, high plant diversity was shown, and a number of endemic, rare, calcicole plants and phytogeographically important plants were found. Nonetheless, numerous and diverse biological resources native have been consistently disturbed or damaged by human activities without some form of protection. Therefore, it is needed to set up strategies for conservation forest vegetation in this study area.

Evaluation of Drainage Improvement Effect Using Geostatistical Analysis in Poorly Drained Sloping Paddy Soil (경사지 배수불량 논에서 배수개선 효과의 지구통계적 기법을 이용한 평가)

  • Jung, Ki-Yuol;Yun, Eul-Soo;Park, Ki-Do;Park, Chang-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.804-811
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    • 2010
  • The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. Knowledge of the spatial variability of soil water properties is of primary importance for management of agricultural lands. This study was conducted to evaluate the effect of drainage in the soil on spatial variability of soil water content using the geostatistical analysis. The soil water content was collected by a TDR (Time Domain Reflectometry) sensor after the installation of subsurface drainage on regular square grid of 80 m at 20 m paddy field located at Oesan-ri, Buk-myeon, Changwon-si in alluvial slopping paddy fields ($35^{\circ}22^{\prime}$ N, $128^{\circ}35^{\prime}$). In order to obtain the most accurate field information, the sampling grid was divided 3 m by 3 m unit mesh by four drainage types. The results showed that spatial variance of soil water content by subsurface drainage was reduced, though yield of soybean showed the same trends. Value of "sill" of soil water content with semivariogram was 9.7 in Pipe Drainage, 86.2 in Open Ditch, and 66.8 in Vinyl Barrier and 15.7 in Tube Bundle.

Recovery Support Service for Neglected Children and Their Families of Origin: Status and Suggestions (방임 및 보호 아동·청소년 원가정 회복지원 시범사업의 현황과 과제)

  • Jeong, Jeeyoung;Anh, Jinkyung;Kim, Eunhye
    • Journal of Family Resource Management and Policy Review
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    • v.25 no.3
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    • pp.87-102
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    • 2021
  • Child abuse and neglect are recently increasing in Korea, and although the government has actively improved the child protection system, the number of abused children and the rate of cases judged as abuse have continuously risen. Given that 75% of child abusers are parents, child abuse and neglect are expected to recur. To prevent such a recurrence, various intervention programs for abused children and their parents are required. The purpose of this study were to design a recovery support service process and investigate the effectiveness of pilot program for families of origin, including neglected(protected) children, to improve the system by which these programs are operated, and formulate policy alternatives that reinforce "family preservation" principles. The pilot program was implemented from June to November 2020 in 4-local healthy family support center. The number of program participants and the frequency of participation in each other differed, because of the difference in number of confirmed coronavirus cases in each region and the requirement for social distancing. Through the program, a community-based service process was developed for neglected(protected) children and their parents, and cooperative networks between related facilities and institutions were established. The study formulated the following recommendations: First, a cooperation system among government departments mandated to provide different services to neglected(protected) children is needed. Second, wider and various channels through which abused children can avail of protective services should be developed within communities. Third, more stable environments for program operation should be cultivated, and cooperative partnerships should be sought for knowledge sharing among relevant government departments. Another necessary measure is for a center to develop its own business model, in which the duplication of services provided by involved organizations is avoided. Finally, clear guidelines, administrative standards, and specific plans for program operation should be arranged. Also regional characteristics are maintained, but services should be standardized.

A Study for Activation Measure of Climate Change Mitigation Movement - A Case Study of Green Start Movement - (기후변화 완화 활동 활성화 방안에 관한 연구 - 그린스타트 운동을 중심으로 -)

  • Cho, Sung Heum;Lee, Sang Hoon;Moon, Tae Hoon;Choi, Bong Seok;Park, Na Hyun;Jeon, Eui Chan
    • Journal of Climate Change Research
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    • v.5 no.2
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    • pp.95-107
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    • 2014
  • The 'Green Start Movement' is a practical movement of green living to efficiently reduce the greenhouse gases originating from non-industrial fields such as household, commerce, transportation, etc. for the 'materialization of a low carbon society through green growth (Low Carbon, Green Korea)'. When the new government took office, following the Lee Myeongbak Administration that had presented 'Low Carbon, Green Growth' as a national vision, it was required to set up the direction of the practical movement of green life to respond to climate change persistently and stably as well as to evaluate the performance of the green start movement over the past 5 years. A questionnaire survey was administered to a total of 265 persons including public servants, members of environmental and non-environmental NGOs, participants of the green start movement and professionals. In the results of the questionnaire survey, many opinions have indicated that the awareness of the green start movement is increasing and the green start movement has had a positive impact on individual behavior and group behavior in terms of green living. The result shows, however, that the environmental NGOs don't cooperate sufficiently to create a 'green living' effect on a national scale. Action needs to be taken on the community level in order to generate a culture of environmental responsibility. The national administration office of the Green Start Movement Network should play the leading role between the government and environmental NGOs. The Green Start National Network should have greater autonomy and governance of the network needs to be restructured in order to work effectively. Also the Green Start Movement should identify specific local characteristics to support activities that reduce greenhouse gas emissions. Best practices can be shared to reduce greenhouse gas emissions by a substantial amount.