• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.624-629
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• 2013

The relation between performance maintenance conditions and those cost efficiency was studied to choose an optimum operating condition in the seawater desalination pretreatment system. A hollow fiber microfiltration module, which was developed with domestic technology, was tested with the various operating conditions such as chemically enhanced backwash cycles and design dosages of a cleaning chemical. Transmembrane pressure was measured to investigate membrane fouling status and cleaning degree. In addition, economic analysis was performed to compare water production costs by the operation condition. As a result, The operation mode III, chemically enhanced backwash at once a day with 100 mg/L of sodium hypochlorite (NaOCl) was selected. The concurrent evaluation between membrane filtration performance and its economic analysis will be suitable to choose an efficient optimum condition.

• Journal of Korean Society of Steel Construction
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• v.20 no.6
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• pp.817-827
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• 2008

The seismic performance of a column splice fabricated with PJP (partial joint penetration) welds for special moment frames was experimentally evaluated in this study. The steel materials that were used for the specimens included SHN490 and SN490 steel, or the newly developed structural steel for seismic application. Fabricating the column splice with PJP welds is highly attractive from the perspective of reducing the welding cost and the construction time. PJP welds in column splices are viewed apprehensively, however, because several tests have shown that PJP welds in thick members tend to become brittle under tensile loads. The column splices in this testing program were designed for the expected plastic moment of the column that current seismic codes typically require. The design strength of partial-penetration welded joints was determined according to the 2005 AISC-LRFD Specification. Three-point loading was applied monotonically, using a universal testing machine, such thatthe column splice joints were subjected to pure tension. The test results showed that the PJP welded splices, if designed properly, can develop a strength exceeding that of the actual plastic moment of the column. The specimen made of the SM490 rolled section, however, showed a brittle fracture at the splice soon after achieving the actual plastic moment of the column. The tensile coupon test results also showed that the material properties of SM490 steel are more unpredictable. Overall, although the test data are limited, the SHN490 and SN490 steel specimens showed a superior and reliable performance.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.258-263
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• 2013

The primary goal of this study was to compute sample sizes required to achieve the each aim of a variety of foot-and-mouth disease (FMD) surveillance programs, using a statistically valid technique that takes the following factors into account: sensitivity (Se) and specificity (Sp) of diagnostic test system, desired minimum detectable prevalence, precision, population size, and desired power of the survey. In addition, sample sizes to detect FMD if the disease is present and also as proof of freedom were computed. The current FMD active surveillance programs consist of clinical, virological, and serological surveillance. For the 2012 serological surveillance, annual sample sizes (n = 265,065) are planned at four separate levels: statistical (n = 60,884) and targeted (n = 115,232) at breeding pig farms and slaughter house, in together with the detection of structural proteins (SP) antibodies against FMD (n = 88,949). Overall, the sample size was not designed taking the specific aims of each surveillance stream into account. The sample sizes for statistical surveillance, assuming stratified two-stage sampling technique, was based to detect at least one FMD-infected case in the general population. The resulting sample size can be used to obtain evidence of freedom from FMD infection, not for detecting animals that have antibodies against FMD virus non-structural proteins (NSP). Additionally, sample sizes for targeted surveillance were not aimed for the population at risk, and also without consideration of statistical point of view. To at least the author's knowledge, sampling plan for targeted, breeding pig farms and slaughter house is not necessary and need to be included in the part of statistical surveillance. Assuming design prevalence of 10% in an infinite population, a total of 29 animals are required to detect at least one positive with probability of 95%, using perfect diagnostic test system (Se = Sp = 100%). A total of 57,211 animals needed to be sampled to give 95% confidence of estimating SP prevalence of 80% at the individual animal-level with a precision of ${\pm}5%$, assuming 800 herds with an average 200 heads per farm, within-farm variance of 0.2, between-farm variance of 0.05, cost ratio of 100:1 of farm against animals. Furthermore, 779,736 animals were required to demonstrate FMD freedom, and the sample size can further be reduced depending on the parameters assumed.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.75-80
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• 2011

Purpose: Europe and U.S use multi-bed therapy rooms. Hereupon, this study aims to examine the safety when current one-bed therapy rooms in Seoul National University Hospital is changed into two-bed ones. Materials and Methods: This study evaluated external exposure by gamma radiation emitted from other patients and internal and external exposure caused by pollutions from other patients in case that Seoul National University Hospital installs a shielding wall between beds in existing therapy rooms. Results: When internal and external exposure was evaluated to evaluate safety of two-bed hospital rooms, 'isolation amount of patients' 5mSv exposure or below is received according to the Atomic Energy Act. Conclusion: With the increasing number of patients with thyoid cancer, patients using therapy rooms are on the rise. Therefore, improving one-person therapy rooms to two-person ones in line with international trend would increase cost reduction and management efficiency, and patients' alienation and isolation can be reduced to increase healing effects.

• Health Policy and Management
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• v.15 no.4
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• pp.136-160
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• 2005

Before introducing the national long-term care insurance in 2008, the want for long term care service has to be estimated and analysed. This study estimates the demand and analyses what determines the want of long term care service. This study investigated data of 3f6 elderlies, that was collected by age stratified random sampling. The elderies resided in Onyang 4 - dong (urban area) and Dogo-myun (rural area) In the city of Asan. The researchers visited the elderlies and their care giver, and assessed their demand for the long term care service and examined physical, mental, socio-economic status by the assessment tools for Korean Long-Term Care System. $64\%$ of the those who are entitled to be served refuse the long term care service. $26.7\%$ of them wants for home care service and $7.9\%$ want facility care service. It is estimated that the want of home care service are three or four times as much as that of facility care service. The demand for long term care service is 5.155 times higher for those who live in rural area (p=0.000), 3.040 times higher for those who do not have spouse(p=0.057), and 3.356 times higher for the people who is in medicaid than medical insurance(p=0.029). However, income(p=0.782), means(p=0.614), living alone(p=0.223), number of family to live with (p=0.341) and age of the elderly(p=0.420) are not related with the demand of long term care service. The assessment tools for Korean Long-Term Care System for need evaluation of the long term care service can reflect the demand well.(p=0.024) If medical care will cover $80\%$ of total cost, the willingness to pay of the out of pocket money of the people with medical insurance is 67,400 Korean Won(66.77 US$) for the home care service and 182,500 Korean Won(180.78 US$) for the facility care service. There is possibility that long term care demand is still small after Introducing the long term care Insurance due to the care given by family members. When developing service delivery system of long term care insurance, rural area has to be given more consideration than urban area because of the higher demand. The people who do not have spouse or are in medicaid have to be given special consideration as well.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.798-806
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• 2013

Precise, fast, and cost-effective identification of crop cultivars is essential for plant breeder's rights. Traditional methods for identification of persimmon cultivars are based on the evaluation of sets of morphological characteristics. However, it is difficult to distinguish closely related cultivars using only morphological traits. This study was conducted to develop DNA markers for identification of the 32 persimmon cultivars in Korea and Japan. A total of 309 randomly amplified polymorphic DNA (RAPD) markers were identified using 40 different random primers. Various number of polymorphic bands ranged from 4 (OPP-08) to 14 (UBC159) were detected with an average of 7.7. Resulting 57 RAPD fragments were selected, and their sequences were determined for developing sequence characterized amplified region (SCAR) markers. As a result, 15 of 57 RAPD fragments were successfully converted to SCAR markers. Single polymorphic bands of the same size as or smaller than the RAPD fragments were amplified depending on SCAR markers. Among these markers, a combination of eight SCAR markers (PS225_200, PSN05_420, PSF13_523, PSN11_540, PS372_567, PS485_569, PSP08_635, and PS631_735) provided sufficient polymorphisms to identify 32 persimmon cultivars. These newly developed markers will be a fast and reliable tool to identify persimmon cultivars.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.943-951
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• 2004

As storing ginger roots under optimum conditions takes high cost, ginger roots are commonly stored in underground tunnels where the maintenance of optimum temperature and humidity is difficult. One of the methods fur long term storage of ginger roots is freezing. The objective of this research was to evaluate effect of storage temperatures and packaging methods on the quality of minced ginger prepared with frozen stored ginger. The minced ginger prepared with frozen stored ginger at $-20^{\circ}C$ was packed in bags, glass bottles and tubes, and then stored at 5 and $-20^{\circ}C$ for quality evaluation at 4 and 15 week-intervals. The changes of surface color, total free sugars, free amino acids and volatile compounds were less in the combined treatment samples than in control during storage, regardless of the storage temperature. The tube packing was the best for maintaining quality of minced ginger during storage among tested packaging methods. Sensory results showed that the minced ginger with the combined treatment and packed in tubes could be stored at 5 and $-20^{\circ}C$ for 12 and 45 weeks, respectively, without a significant drop in palatability.

• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.1
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• pp.2503-2519
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• 1972

The studies were carried out to find the cause and the quantitative evaluation of sea dike materials loss which is occured during the period of construction works for the tideland reclamation projects on the west coast of Korea. Major subjects to studies were to establish the typical relationships between the tidal flow and the movement of dike materials, the tidal-flow and the erosion, the dike materials and the ratio of material movement(losses), construction methods and the ratio of materials movement (losses). Based on the above subjects, the studies were made for the purpose of obtain the following informations; (1) Collecting and evaluaing the data of dike material losses due to foundation settlement, from designed existing dikes on the west coast. (2) By the field investigation at A-San Sea Dike, Pyong Taek Project, the Comparison would be made by the relationships between the tide velocity and the movement of dike foundation under the natural conditions and the period of construction so that find out the relationship between the dike materials of foundation situation and settlements. With regard to the dike construction works, it is so difficult to calculate the exact quantity of material losses due to the foundation settlements. The major factors that affect the settlement losses of the dike materials are: (1) Topographical variation (2) Swepting the sectional area of dike by the tide velocity. (3) Dumping riprap to the outerside of dike during the period of construction works. (4) Sectional area losses by the cause of occurence of the new tide channels. (5) material losses by the heavy storms. (6) Consolidation settlement by the foundation weakness. (7) Material losses by the earth materials by tide flow. Most hi호 material losses were occured by the Consolidation settlement due to the foundation weakness, the maximum tide velocities due to decrease the cross sectional area of the gaps and erosion of foundation due to the range of tide, Inner and outerside of dike, or dike material loses due to the tide flow. Final conclusion would be obtained by the continuous measurement of consolidation settlement at the stage of final clusure of the dike. (It is scheduled to close on the end of 1972) However, intermediate conclusion can be introduced as follows: (1) The estimation of material(losses) during the period of construction works for the existing sea-dikes up to date were only empirical. The material losses at the general closure for design was estimated at 10% of the riprap, 20% of the earth materials, and 20% of the riprap, 40% of the earth materials at the final closure of the dike. The final closure estimated double quantity to the general closure, but it is still doubt. (2) The ratio of consolidation settlements was found smaller than the calculated quantity. It can be foreseen that settlement speeds is higher thom the calculated speeds. (3) The movement of dike foundation under the natural conditions were not so depends on the geological conditions of the foundation. (4) When the tide velocities was estimated 100 at the normal tide, it was estimated 125 at the high tide and 55 at the low tide. The tide velocities at the low tide shows apparently lower than the high tide and the higher velocities at the deep water depth.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.171-178
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• 2008

Compressive strength of concrete has been regarded as a very important parameter of the quality control both in new and existing concrete pavement. It has been used a lot as the concrete strength evaluation both in the various-mixture-using laboratory and construction field using the same mixture. An error usually occurs in the test experiments of the strength, even in the test experiments with evenly mixed and compacted specimens of the compressive strength. It is caused by the 'manually operated' compressing testing, or by the specimens preparation with eccentricity. When compressive strength of evenly mixed concrete is investigated by the curing ages at the construction field, there have to be lots of specimens. And it needs much labor and cost. To substitute the endlessly repeated test experiments of compressive strength, presumption of compressive strength, by nondestructive tests, is needed. In this study, elastic waves were used among various nondestructive tests. Compressive strength of concrete was presumed according to the curing ages, by using the shear wave velocity which is not affected by restricted conditions. In the result, shear wave velocity is very closely related to the compressive strength at the evenly mixed concrete.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.105-112
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• 2013

PURPOSES : Compared to the criteria from advanced countries, Korea has conservative criteria for the buried depth of pipeline (about 30~70cm deeper) causing the waste of cost and time. Therefore, this research investigated the effect of various buried depths of pipeline on pavement performance in order to modify the criteria to be safe but economical. In addition, a recycled aggregate which is effective in economical and environmental aspect was evaluated to be used as a refilling material. METHODS : In this study, total 10 pilot sections which are composed with various combinations of pavement structure, buried depth of pipeline, and refilling material were constructed and the telecom cable was utilized as a buried pipeline. During construction, LFWD (Light Falling Weight Deflectometer) tests were conducted on each layer to measure the structural capacity of underlying layers. After the construction is completed, FWD (Falling Weight Deflectometer) tests and moving load tests were performed on top of the asphalt pavement surface. RESULTS : It was found from the LFWD and FWD test results that as the buried depth decrease, the deflections in subbase and surface layer were increased by 30% and 5~10%, respectively, but the deflection in base layer remained the same. In the moving load test, the longitudinal maximum strain was increased by 30% for 120mm of buried depth case and 5% for 100mm of buried depth case. Regarding the effect of refilling material, it was observed that the deflections in subbase and surface layer were 10% lager in recycled aggregate compared to the sand material. CONCLUSIONS : Based on the testing results, it was found that the change in buried depth and refiliing material would not significantly affect the pavement performance. However, it is noted that the final conclusion should be made based on an intensive structural analysis for the pavement under realistic conditions (i.e., repeated loading and environmental loading) along with the field test results.