• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2001년도 학술대회지
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• pp.410-415
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• 2001

Earned Value Management System(EVMS)은 최근 건설 프로젝트를 관리하는데 매우 유용한 도구로 인식되고 있으며, 정부차원에서 적극적으로 도입을 검토하고 있는 선진 관리기법이다. 이 EVMS는 미국방성에 의해 1960년대부터 프로젝트의 효율적인 관리를 위해 개발된 C/SCSC에 기반을 두고 있으며, 국내외에서 정부발주공사뿐만 아니라 민간발주의 건설프로젝트를 관리하는 도구로 활용하기 위해 연구가 활발하게 진행되고 있다. 본 연구에서는 공정관리 프로그램과 복합작업모델(Workpackaging model)을 바탕으로 건설프로젝트의 EV계획과 분석이 효과적으로 이루어질 수 있도록, 제조업의 재고관리모형중의 한 형태로 조립제품의 자원운영계획을 수립하는데 우수한 기법으로 알려진 MRP기법을 활용하여 EVMS가 건설현장에서 보다 용이하고, 효과적으로 활용될 수 있는 방안을 제시하고자 한다.

• Journal of Plant Biology
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• 제12권4호
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• pp.9-18
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• 1969

In the previous paper(part III), a certian relationships between the changes of chlorinity and organic acid released from organic material were seemed to be concened to each other in saline soil suspension. Such a possibility had been a cause to take this experiments and this experiment was carried out under the treatment of organic acid crystal, oxalic acid and succinic acid, to the soil suspension(soil: water=20g:40cc) directly. The amount of organic acid treated to the suspension were related to the contents of organic material, as amount of organic acid per gram of organic material(391.76mg). The saline soil suspension were grouped and treated with the acids in order of 78.35mg(Group 1), 391.76mg(Group 2) 979.4mg(Group 3), and 1958.8mg(Group 4), respectively. Treated suspension had been incubated at room temperature and extract from suspension was used for analysis. Followings are summary of this report. 1) Changes of pH in soil suspension appeared a little increase after the treatment of organic acid until 168 hours. 2) Total acidity of soil suspension showed a variation, however, the values of total acidity appeared not to be increased or decreased during the period of experiment. 3) Sugar contents of soil suspension was increased until 168 hours after treatment. These results are similar tendency to the previous paper. 4) Addition of organic acid to soil suspension was confirmed not to be effective method for desalination from saline soil. Chlorinity of group 3 and 4 which were treated with high concentration of organic acid showed a decrease comparing to control group.

• 한국생산제조학회지
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• 제6권3호
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• pp.111-117
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• 1997

The sudden-stop apparatus is made to measure the residual stress of the infinitesimal area at the turning work surface by using the X-ray stress apparatus. This study is trued to make the cutting work the instantaneous stopping state in the normal working state. The behaviour of work material near the tool is estimated. The estimation method is that the distribution of residual stress can be also measured. The object is to clarify and control the mechanism to leave the adequate stress of the finishing surface. It's beginning is due to observe the occurrence state of the residual stress at the cutting work. The result obtained by this study is as follows. The chips are not separated from the work materials at all the cutting experiments of built-up edges or the shearing areas etc. which can be precisely observed by using the sudden-stop apparatus. The strain of movable system which can be seen at the part of working layer means the size of strain. This experiment proves that the working strain should be lessened to make the size of strain control the residual stress happened at the cutting surface.

• 콘크리트학회논문집
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• 제27권1호
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• pp.29-35
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• 2015

최근 연구되고 있는 해상 초대형 부유 콘크리트 구조물의 제작은 현장 타설이 어렵다는 단점이 있으므로 프리캐스트 콘크리트로 제작한 모듈을 수상에서 인양 후 프리스트레스력으로 접합 및 제작하는 것을 목표로 한다. 그러나 해상 환경에서 발생하는 다양한 하중 및 예상되는 상부 구조물에 의한 하중을 고려하였을 때, 프리스트레스력으로 접합되는 콘크리트 모듈 간의 접합부의 안정적인 거동 및 성능이 요구된다. 이에 프리스트레스력이 적용되기 전 가접합에 수중용 에폭시를 이용한 접합 방법이 고려되고 있는데, 수중용 에폭시는 고점성의 재료로서 내부에 공극이 발생하기 쉽다. 이를 해결하기 위하여 마이크로 실리카를 혼입하여 공극을 감소시킨 수중용 에폭시를 이용하여 콘크리트 부유체의 접하 거동에 대한 평가가 요구된다. 그러므로 이번 연구에서는 마이크로 실리카를 혼입한 수중용 에폭시를 이용하여 가접합하고 프리스트레싱을 적용한 시험체를 제작하여 성능을 평가하였다. 마이크로 실리카를 혼입한 수중용 에폭시로 접합된 콘크리트 모듈은 프리스트레싱만을 적용한 시험체에 비하여 균열 발생 및 응력 집중 현상이 완화되었으며, 최대 하중 및 변위는 일체형 RC 시험체에 비하여 10% 미만의 감소율을 나타내어 모듈형 콘크리트 부유체의 수상 접합을 위한 안정적인 접합재료로 사용 가능할 것으로 보인다.

• 한국산업보건학회지
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• 제24권2호
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• pp.122-129
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• 2014

Objectives: Because of its properties such as resistance to heat, chemicals and corrosion; tensile strength; sound absorption; and affordable price, asbestos has been widely used as a building material, fire resistant and retardant, thermal and heat insulator, soundproofing material, and electrical insulation. Since the prolonged inhalation of asbestos can cause serious illnesses such as lung cancer, mesothelioma, and asbestosis after an incubation period of 20 to 40 years, the mineral was classified as a Group 1 carcinogen by the International Agency for Research on Cancer, an intergovernmental agency forming part of the World Health Organization. Children and infants are more at risk than are adults if they are exposed to carcinogens, due to aweaker immunity that has not yet been fully developed. Most childcare centers are operated all day and children tend to spend a great amount of time in the centers. This is why it is important for them to be systematically isolated from environments that may expose them to asbestos. Materials: In order to understand both indoor and outdoor hazards to which children may have been exposed, the study focused on actual surveys of asbestos used in childcare centers, paying special attention to slate-roofed buildings in the vicinity of the centers. Results: A survey of a total of 211 childcare centers showed that the buildings of 18.1% of the centers contained asbestos, with 60.53% of the material being found in classroom ceilings. "Tex" was the most used material for ceilings, making up 89.47% of all ceilings. An outdoor survey showed that childcare centers in Daegu Metropolitan City had an average of 143 slate-roof buildings within a distance of 1km. Conclusions: Buildings housing mainly toddlers, children, teenagers and others more vulnerable to the toxicity of asbestos are not subject to asbestos investigation by law. A legal and practical basis for asbestos control is required for such buildings. In particular, housing materials which contain asbestos in day care centers require asbestos control. GIS should be used to identify the location of buildings with slate roofing materials in the vicinity of daycare centers in order to gauge toxicity of exposure to asbestos caused by potential asbestos friability possibility in outdoor conditions.

• 생명과학회지
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• 제19권6호
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• pp.832-835
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• 2009

본 시험은 사과의 주요 왜성 대목인 M.9 대목의 묻어떼기에 의한 번식 시 복토시기, 차광, 복토재료 및 복토부위의 수분 정도 등 발근에 영향을 미치는 몇 가지 요인들을 살펴보고 발근율을 높이는 방법을 구명하고자 하였다. M.9 대목의 묻어떼기 번식 시 모수의 차광 처리 및 복토시기 별 발근 촉진 효과는 조기 복토(신초 2cm 신장 시 복토)처리가 관행구 보다 유의하게 높았다. 복토 재료 별 발근 촉진 및 생육을 시험한 결과 질석, 팽연왕겨, 톱방 등은 대조구인 양토보다 유의하게 높았다. 복토 부위의 수분 상태별 발근효과 및 생육을 시험한 결과는 -40 kPa 처리구의 발근율은 99%로 -60 kPa 처리구와 무처리의 발근율 91% 보다 유의하게 높았으며, 근수가 많았고 근장도 길었다. 그러므로 M.9 대목의 묻어떼기 번식 시 복토시기가 빠를수록, 복토재료는 질석, 팽연왕겨, 톱밥 등을 사용하고, 복토부위의 수분 상태는 -40 kPa로 유지를 하는 것이 발근율 및 우량묘생산에 유리할 것이라 생각된다.

• 대한예방한의학회지
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• 제4권2호
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• pp.193-204
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• 2000

In this study, advanced model for quality control of oriental medicine and methods for practice was suggested through literature inspection, analysis of foreign system such as China and Japan, survey analysis on the current system, quality analysis of randomly selected oriental medicine samples, and intensive discussions among oriental medicine specialists 1. The quality of oriental medicine should be consistently controlled by Ministry of Health and Welfare form its cultivation or import to its circulation process to final consumer 2. All oriental medicines should be circulated as standardized goods which should be marked by lot numbers. The packing material and Packing size should be liberalized. The qualify should be differentialized though free competition among makers. 3. Realistic standards for pesticide, heavy metal and decolorant should be established though long-term monitoring process according to each oriental medicine's origin, therapeutic part, cultivation area, harvesting time, and cultivation method. 4. Ministry of Health and Welfare should educate oriental medicine's quality control personnel regularly or on demand, and establish specialist pool. Ministry of Health and Welfare should also establish oriental medicine information system to provide informations about quality of domestic or foreign oriental medicinal raw materials. 5. The government should provide information about foreign of oriental medicine market to importers. Quality of imported oriental medicine should be inspected before its customs clearance, and all imported oriental medicine should be circulated by standardized oriental medicine makers. 6. Oriental medicine's pharmacopoeia should be Published to provide quality standard of oriental medicine and improve it.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.109-114
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• 2014

After the Fukushima accident in 2011, it was revealed that nuclear power plant has the vulnerability to SBO accident and its extension situation without sufficient cooling of reactor core resulting core meltdown and radioactive material release even after reactor shutdown. Many safety systems had been developed like PAFS, hybrid SIT, and relocation of RPV and IRWST as a part of steps for the Fukushima accident, however, their applications have limitation in the situation that supply of feedwater into reactor is impossible due to high pressure inside reactor pressure vessel. The concept of hybrid heat pipe with control rod is introduced for breaking through the limitation. Hybrid heat pipe with control rod is the passive decay heat removal system in core, which has the abilities of reactor shutdown as control rod as well as decay heat removal as heat pipe. For evaluating the cooling performance hybrid heat pipe, a commercial CFD code, ANSYS-CFX was used. First, for validating CFD results, numerical results and experimental results with same geometry and fluid conditions were compared to a tube type heat pipe resulting in a resonable agreement between them. After that, wall temperature and thermal resistances of 2 design concepts of hybrid heat pipe were analyzed about various heat inputs. For unit length, hybrid heat pipe with a tube type of $B_4C$ pellet has a decreasing tendency of thermal resistance, on the other hand, hybrid heat pipe with an annular type $B_4C$ pellet has an increasing tendency as heat input increases.

• 대한치과기공학회지
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• 제37권3호
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• pp.169-178
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• 2015

Purpose: This study was to investigate usage satisfaction of multi type handpiece with equipped air-jet function Methods: The subjects of this study through the survey was conducted for fifty-nine dental technicians in Daegu and Gyeongsangbukdo from the May 7 to 19, after the June 23 to July 4 2014. The survey was about the function and quality through user testing environment by cutting zirconia specimens using appliance for zirconia. The collected date was analyzed by the statistical program SPSS Win Ver 19.0 for the satisfaction of handpiece and control system. To test for significance on each item, p<0.05 had been decided a standard. General characteristics and relationship between the handpiece and control system was performed correlation analysis. Results: The results of this study is as follows. 35 dental technicians had 1~2 years career in zirconia part as the highest 59.3%, 95% of subjects expected that the prospects for the zirconia material have bright prospects. The satisfaction of multi type handpiece and control system design and function showed a significant difference. Subjects satisfied with the design and function of the multi type showed negative correlation with those of Standard. The satisfaction of multi type handpiece showed 3.37 points of air jet, 3.05 points of noise level, 2.69 points of water flow rate, and 1.98 points of cruise function. Sample differences in all parameters showed a statistically higher difference. Conclusion: High-speed cutting mechanism of multi-type is recommended working with zirconia materials and the multi-type unit combined handpiece motor, air-turbine and air-gun will be expected the increase of user due to the high satisfaction of air jet.

• Journal of Periodontal and Implant Science
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• 제38권2호
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• pp.163-170
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• 2008

Purpose: Biphasic calcium phosphates have been of great interest recently. Mixing adequate ratios of hydroxyapatite(HA) and beta-tricalcium phosphate($\beta$-TCP) allowed to control the resorption rate without distorting its osteoconductive property. This study evaluated the bone formation effect of newly developed biphasic calcium phosphate(BCP) in calvarial defect of rabbits. Materials and Methods: 6 male New Zealand rabbits were used. Four defects with 8mm in diameter were created on each animal. BCP with HA/$\beta$-TCP ratio of 7:3 and particle size of $0.5{\sim}1.0\;mm$ was used as the test group and bovine bone with $0.25{\sim}1.0\;mm$ particle size, as the control group. Both test and control group materials were randomly implanted in the calvarial defects and were covered witha polymer membrane. The animals were sacrificed after 12, 24, and 48 weeks of implantation under general euthanasia. Resin blocks were obtained and were stained by masson's trichrome for histological observation. Results: Overall results were uneventful without any defect exposure or inflammation. The amount of new bone formation and bone maturity increased with increase in healing period at both groups. New bone in test group was mostly formed along the material particle surrounded by osteoblasts, and observation of osteoblastic stream was also present. Bone maturity increased as it was closer to thedefect margins. Under the same healing period, the test group showed more bone formation than the control group with more stable bovine bone particles remaining even after 48 weeks, whereas considerable resorption took place in BCP. Almost total defect closure was observed in test group with new bone formation in the central part of the defect. However, limited new bone formation was observed in the control group. Conclusion: Within the limits of the study, the present study reveals the newly developed BCP to be a good osteoconductive material. However, further studies are needed to be conducted in a different study model with a larger sample size.