• 자원환경지질
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• 제37권1호
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• pp.49-59
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• 2004

The concectration and distribution of contaminants obtained from a contaminated land investigation or an environmental geochemistry survey constitutes the basis of a decision-making process on environmental policies or of scientific researches. As the quality of data determines the reliability of the result, the investigation plan should be adjusted according to the purpose of the investigation. In general, the effort to improve the data quality had been focused mainly on the QA/QC procedures in laboratories. The rapid progress of analytical instrument has also contributed toward improving the analytical precision to a sacrificable degree. Nevertheless, in many cases, it is not the analytical precision that needs improvement for the better precision of overall measurement process: it is rather during the sampling process in the field that is responsible for the poor precision. To assess the data quality on a measured value, ISO recommends to provide information on "measurement uncertainty" along with the measured value. The measurement uncertainty in an environmental measurement context can be explained as the statistical number that expresses the degree of the uncertainty stemming from the sampling and analytical procedures. There is a cost involved in order to improve the precision of sampling and analytical methods so as to decrease the degree of measurement uncertainty. The economical point of compromise in an investigation planning can be achieved when the allowable degree of uncertainty has been set before-hand. The investigation can then be planned accordingly not to exceed the uncertainty limit. Furthermore, if the measurement uncertainty estimated from the preliminary investigation can be separated into sampling and analytical uncertainties, it can be used as a criterion where the resources for the investigation should be allotted cost-effectively to reinforce the weakest link of the whole investigation process. This paper aims to present a method of estimating the level of measurement uncertainty of a measured contamination concentration at a site used as an example and to show how the estimated uncertainty can be applied to serve the particular purpose of an investigation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권2호
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• pp.178-183
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• 2001

Since the introduction of the concept of osseointegration, the success rate of dental implant has increased dramatically. So, the uses of dental implant in the treatment of partially or fully edentulous patients have played an important role in dental rehabilitation. Regardless of high success rate of dental implant, some amounts of fixtures cannot help failing. We can classify dental implant failure according to timing, causative factor, etc. This study is focused on dental implant fixture failure, occurring during preprosthetic stage. There are various reasons that cause implant failure on this periods, such as improper patient selection, poor bone quality, and periimplantitis, etc. We investigate the survival rate of 1058 fixtures, which installed in 306 patients in our clinic from January 1997 to December 1999, according to type, sex, location, fixture length and width, using Kaplan-Meier product-limit method and to compare each other with log-rank test. Overall survival rate was 96.80%, and 33 implants failed over the preprosthetic stage. Our survey data identified posterior location of mandible as being associated with implant failure(P<0.05).

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(환경)
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• pp.440-449
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• 1994

Current risk assessment practices largely reflect the need for a consistent set of relatively rapid, first-cut procedures to assess 'plausible upper limits' of various risks. These practices have important roles to play in 1) screening candidate hazards for initial attention and 2) directing attention to cases where moderate-cost measures to control exposures are likely to be warranted, in the absence of further extensive (and expensive) data gathering and analysis. A problem with the current practices, however, is that they have led assessors to do a generally poor job of analyzing and expressing uncertainties, fostering 'One-Number Disease' (in which everything from one's social policy position on risk acceptance to one's technical judgment on the likelihood of different cancer dose-response relationships is rolled into a single quantity). At least for analyses that involve relatively important decisions for society (both relatively large potential health risks and relatively large potential economic costs or other disruptions), we can and should at least go one further step - and that is to assess and convey both a central tendency estimate of exposure and risk as well as our more conventional 'conservative' upper-confidence-limit values. To accomplish this, more sophisticated efforts are needed to appropriately represent the likely effects of various sources of uncertainty along the casual chain from the release of toxicants to the production of adverse effects. When the effects of individual sources of uncertainty are assessed (and any important interactions included), Monte Carlo simulation procedures can be used to produce an overall analysis of uncertainties and to highlight areas where uncertainties might be appreciably reduced by further study. Beyond the information yielded by such analyses for decision-making in a few important cases, the value of doing several exemplary risk assessments in. this way is that a set of benchmarks can be defined that will help calibrate the assumptions used in the larger number of risk assessments that must be done by 'default' procedures.

• 한국환경과학회지
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• 제9권5호
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• pp.415-422
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• 2000

In this study the removal possibility of nutrients of T-P, NH3-N, NO3-N and T-N is examined through a positive experimental study using submerged biofilter of media packing channel method. From the analysis of nutrients removal efficiency for each run of the collected sample following results are obtained. Firstly the result of N/P surveying for inflow shows serious value that excess the limit value of 20 as the values are in the range of 12.0~42.7 and the average is 25.73. Secondly the highest concentration of the incoming NH3-N reaches double of the standard since the concentrations of NH3-N and NO3-N for inflow shows 0.06mg/$\ell$ and 2.5~3.8mg/$\ell$ respectively and the average removal rate which passed the submerged biofilter adopted in this study is a satisfactory level. Next the average removal rate of T-P of 51.5% shows the possiblity of entrophication removal since the removal rate of T-P of 66.8~68.8% in relative low temperature period of RUN 1~2 appeared higher than in RUN 3~6 and T-N shows relatively poor result with the average removal rate of 34.1% And it is known that the bigger BOD/P and BOD/N are the more removal rate increases from the examination result of the relation between BOD/P and BOD/N and the treatment water T-P and T-N to decide the relation with the concentration of organic matters and though that the appropriate proportion is necessary for effective removal of nitrogen and phsophorus.

• 조명전기설비학회논문지
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• 제23권4호
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• pp.1-7
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• 2009

본 연구에서는 농촌 청소년 공부방을 대상으로 조명환경 실태조사를 실시하였다. 그 결과, 공부방의 평균 공간의 크기는 11.42[$m^2$]이며, 주로 광원은 형광등을 사용하였으며 조명사용방법은 전반조명만 이용하는 경우가 73.8[%]이며, 배광방식은 직접조명 방식을 주로 사용하고 있었다. 또한 스탠드를 소유하고 있는 가구는 45.7[%]이었으며, 국부조명인 스탠드를 사용하는 비율은 전체 조사대상의 20[%]에 지나지 않아 시작업이 효과적이지 못하였다. 내부공간 조도는 평균 131.82[lx]이며, 책상면 조도는 253.64[lx]로 최저허용조도의 42.3[%]에 해당하는 열악한 실정이었으며, 균제도는 평균 35.61[%]로 나타났다. 또한 사용자의 조명환경에 비해 만족도는 3.93점으로 높아 조명에 대한 인식이 매우 부족한 것으로 사료된다.

• 한국응용과학기술학회지
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• 제28권4호
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• pp.508-516
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• 2011

Hydrotreated biodiesel(HBD) is paraffinic bio-based liquid, with the chemical structure $C_nH_{2n+2}$, originating from vegetable oil(the process can also be applied to animal fat). The oil or fat is treated in a number of process, the most important being hydrogenation, in order to create a bio-based liquid diesel fuel. During the hydrogenation, oxygen is removed from the triglyceride and converted into water. Propane is formed as a by product and can be combusted and used for energy production. HBD can be used in conventional diesel engines, pure or blended with conventional diesel, due to its similar physical properties to diesel. This study reports the quality characteristics with chemical and physical properties as an alternative diesel fuel. Especially, HBD showed higher cetane value and number than FAME, and it is consisted of $C_{15}$ - $C_{18}$ n-paraffinic compounds. We also describes quality characteristics of HBD blends(2, 5, 10, 20, 30, 40, 50 vol%) in automotive diesel. HBD blends(max. 20 vol%) were the limit by the Korean specification due to poor low temperature characteristics.

• Journal of Chest Surgery
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• 제23권5호
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• pp.1003-1008
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• 1990

Primary choriocarcinoma of the lung is extremely rare and have been reported ten and several cases only in the literature. It is very difficult to confirm the "Pure primary pulmonary choriocarcinoma" clinically, so most cases that have been reported in the literature confirmed by autopsy and the prognosis is relatively poor compared with metastases. We experience one case of the primary pulmonary choriocarcinoma. She was 53 year old multiparous woman[4 \ulcorner0 \ulcorner2 \ulcorner0] who complain right chest pain for 4 years. On plain film and computerized tomogram of the thorax at admission, 2.5cmx3.5cmx5 cm sized, well demarcated ovoid mass was founded on the right middle lobe just below the parietal pleura and growing rapidly on plain film to 5cm x 6.5cm x 7cm after 15 days. We confirm the choriocarcinoma in the lung by percutaneous needle aspiration biopsy and strongly suspect primary after various examination for rule out metastases from the ovary or uterus. We perform middle lobe lobectomy because that can not confirm the primary or the metastases because there are not complete histological examination by bilateral ovariectomy and hysterectomy, and under the belief that extragestational or extragonadal primary choriocarcinoma is more resistant to the chemotherapy, and could be reduce the duration of hospitalization and the amount of chemotherapy used to achieve remission On 14th postoperative day, serum p-HCG level was returned to normal limit, and perform chemotherapy two times on 3rd and 5th week for prevention surgical traumatic hematogenous metastases or undetected microfocus, but the patient expire on 68th postoperative day due to intracerebral hemorrhage in the intracranial choriocarcinoma which strongly suspected surgical traumatic hematogenous metastases.etastases.

• KCI Concrete Journal
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• 제14권4호
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• pp.145-150
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• 2002

Reinforced concrete is inherently a durable composite material. When properly designed for the environment to be exposed and carefully constructed, reinforced concrete is capable of giving maintenance-free performance. However, unintentionally using improper materials such as non-washed sea sand having much salt together with poor controlled quality, or the concrete are placed in highly severe environment such as marine atmosphere, the corrosion of reinforcing steel in concrete becomes one of the most significant concerns of concrete. The purpose of this experimental research is to evaluate the performance of corrosion inhibitors for normal strength and high strength concrete, and to propose desirable measures for controlling corrosion of reinforcing steel in concrete. Test specimens in normal strength and high strength concrete were made with and without corrosion inhibitors. The accelerated corrosion test for reinforcing steel in concrete was adopted in accordance with JCI-SC3, which required the periodic 20 cycles for 140 days. One cycle includes 3 days for the wetting condition of $65^{\circ}C$ and $90\%$ RH, and 4 days for the drying condition of $15^{\circ}C\;and\;60\%$ RH. It was observed from the test that corrosion inhibitors in normal strength concrete and high strength concrete showed excellent corrosion resistance for reinforcing steel in concrete, but the silica fume in high strength concrete was found to have a negligible corrosion resistance if not used with corrosion inhibitors, since the chloride corrosion threshold limit in concrete containing silica fume without corrosion inhibitor was found to be considerably smaller than that of the case with corrosion inhibitor.

• 한국간호교육학회지
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• 제10권2호
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• pp.239-251
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• 2004

The purpose of this study was to find out the effects of education for prevention of child sexual abuse (rape, sexual assault, sexual harassment etc.) of children in elementary school students. Incidences of sexual abuse in Korea is ranked 3rd in the world. Sexual abuse of children, particularly, is one of the most serious crimes that affect both the victimized children and their family. The issue related to sexual abuse of children has been ignored, and there is a lack of systematic education to prevent sexual abuse of children either for children or their parents. Furthermore, lack of knowledge and poor attitude of teachers limit their capability to provide education for sexual abuse prevention to the children. The education for teachers may change their knowledge of the sexual abuse and their attitude toward it and improve their capability in helping children. 223 Korean elementary school students participated in this study. Research design was One group pretest-posttest design. The education given to the subjects included 4 hours through the multimedia CD-ROM on the prevention of child sexual abuse. The education program was developed based on a survey. School- aged- children, parents, and teachers were interviewed to reveal their educational needs based on their experiences related to sexual abuse. This program includes such as safety education, crisis management, resource person(s), and phone numbers of available hospital. Data was collected before, during and after the education was given to the subjects, to assess their knowledge and attitude toward child sexual abuse. Two instruments were used in this study. Using Cronbach's ALPHA validity and reliability of 2 instruments were tested. The analysis of the data was done with Window SPSS 10.0 for descriptive statistics, t-test and ANOVA. The results of this analysis were as follows : 1. After education, the score of school nurses knowledge was higher than before(t= -4.677, p=0.000). 2. After education, the score of school nurses attitude was not higher than before (t=0.131, p=0.896). The findings from this study will provide an intervention strategy for prevention of sexual abuse in children.

• 한국사회복지학
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• 제36권
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• pp.129-146
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• 1998

서론에서는 독일과 일본의 공적개호보험의 등장배경과 공적개호보험의 연구가 필요하다는 것을 전제하고, 제2장에서는 일본에서 최근 사회보장체계에 대한 새로운 구상배경을 (1) 지금까지의 사회보장정책이 안고 있는 한계점과 (2) 고령화의 진전에 따른 요개호대상자의 증대, 그리고 (3) 노인복지재원의 확보 등에 초점을 맞추어 고찰하고 있다. 제3장에서는 공적개호보험제도 도입을 위한 구체화 과정을 (1) "개호보험제도안 대강"(介護保險制度案 大綱) 도출경과와, (2) 그 대강(大綱)에 나타난 제도의 기본골격을 고찰하고, 제4장에서는 2000년 4월에 일본에서 본격적으로 실시할 것에 대비한 제반준비와 실천과제에 대해서 (1) 서비스 담당기관 및 체계 (2) 서비스 내용 및 방법 (3) 실시과정에서 나타날 제 문제 등에 대해 설명하고 있다.