This study aimed to develop a method to optimize residual chlorine concentrations in the process of providing water supply. To this end, this study developed a model capable of optimizing the chlorine input into the clearwell in the purification plant and the optimal installation location of rechlorination facilities, and chlorine input. This study applied genetic algorithms finding the optimal point with appropriate residual chlorine concentrations and deriving a cost-optimal solution. The developed model was applied to SN purification plant supply area. As a result, it was possible to meet the target residual chlorine concentration with the minimum cost. Also, the optimal operation method in target area according to the water temperature and volume of supply was suggested. On the basis of the results, this study derived the most economical operational method of coping with water pollution in the process of providing water supply and satisfying the service level required by consumers in the aspects of cost effectiveness. It is considered possible to appropriately respond to increasing service level required by consumers in the future and to use the study results to establish an operational management plan in a short-term perspective.

The microstructural evolution and modulation of mechanical properties were investigated for a Ti65Fe35 hypereutectic alloy by addition of Bi53In47 eutectic alloys. The microstructure of these alloys changed with the additional Bi- In elements from a typical dendrite-eutectic composite to a bimodal eutectic structure with primary dendrite phases. In particular, the primary dendrite phase changed from a TiFe intermetallic compound into a β-Ti solid solution despite their higher Fe content. Compressive tests at room temperature demonstrated that the yield strength slightly decreased but the plasticity evidently increased with an increasing Bi-In content, which led to the formation of a bimodal eutectic structure (β-Ti/TiFe + β- Ti/BiIn containing phase). Furthermore, the (Ti65Fe35)95(Bi53In47)5 alloy exhibited optimized mechanical properties with high strength (1319MPa) and reasonable plasticity (14.2%). The results of this study indicate that the transition of the eutectic structure, the type of primary phases and the supersaturation in the β-Ti phase are crucial factors for controlling the mechanical properties of the ultrafine dendrite-eutectic composites.

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

In this study, a model was developed to predict for Disinfection By-Products (DBPs) generated in water supply networks and consumer premises, before and after the introduction of advanced water purification facilities. Based on two-way ANOVA, which was carried out to statistically verify the water quality difference in the water supply network according to introduce the advanced water treatment process. The water quality before and after advanced water purification was shown to have a statistically significant difference. A multiple regression model was developed to predict the concentration of DBPs in consumer premises before and after the introduction of advanced water purification facilities. The prediction model developed for the concentration of DBPs accurately simulated the actual measurements, as its coefficients of correlation with the actual measurements were all 0.88 or higher. In addition, the prediction for the period not used in the model development to verify the developed model also showed coefficients of correlation with the actual measurements of 0.96 or higher. As the prediction model developed in this study has an advantage in that the variables that compose the model are relatively simple when compared with those of models developed in previous studies, it is considered highly usable for further study and field application. The methodology proposed in this study and the study findings can be used to meet the level of consumer requirement related to DBPs and to analyze and set the service level when establishing a master plan for development of water supply, and a water supply facility asset management plan.

This study concerned the analysis on the efficiency of the conversion of water tank type supply system to direct water supply system to examine the feasibility of the conversion, as well as the calculation of optimal conversion range that enables the supply of safe, high-quality water at stable pressure in accordance with the standards of water supply facility. The results of this research showed that when converting water supply system from water tank type supply system to direct water supply system, more nodal points could be properly converted and more reduction of electricity usage was expected in case water pressure rather than residence time was fixed. This means that higher efficacy can be obtained by fixing water pressure when converting water supply system. However, since the number of the locations that received on-spot inspection was small and the electricity usage measured was not exclusively by water supply facility, it is difficult to judge that such reduction of electricity usage accurately represents reduced electricity usage by water supply facility alone. therefore, after having secured on-spot information about a larger number of locations in apartment complexes that have converted water supply system, and utilizing information about electricity usage exclusively by water supply facility, the proposed method of this research could be applied to accurately deducing expected reduction of electricity usage by water supply facilities of various other apartment complexes. It is also considered possible to deduce an effective operation method of water supply system by finding out an area that shows low pressure or low residual chlorine concentration in the optimal conversion range of water supply, followed by estimating the proper location of pumping station or the proper chlorine dosage at the power purification plant that supply water to the target area.

It is considered necessary to renewal a considerable number of water supply facilities in Korea because they began to be intensively buried in the period of rapid economic growth. Accordingly, local water providers are required to take measures against this situation, but they have currently been caught in a vicious circle of the lack of budget spent in renewing water supply facilities because county-based small-scale local water supply cannot afford to cover annual expenditures with their revenues from water rates. Therefore, this study developed an optimal renewal planning model capable of achieving a balance of financial revenue and expenditure in local water supply using nonlinear programming and furthermore of minimizing the total cost incurred during the analysis. To this end, this study selected the water supply area located in County Y as a research area to build the financial revenue and expenditure and used Solver function provided by Microsoft Excel to use nonlinear programming. As a result, this study developed an optimal renewal planning model minimizing incurred costs in consideration of 6 items in the financial revenue and expenditure. The optimal renewal plan was modeled according to the available annual budget. As a result, this study proposed SICD, a scenario to minimize total costs from the perspective of water suppliers, and SITS, a scenario to minimize the increase in water rates from the perspective of consumers. It can be said that the method proposed in this study is the core of the optimal financial and renewal plans as a final stage of asset management for water supply facilities. Therefore, it is considered possible for local water providers to use the method proposed in this study according to circumstances for the asset management of water supply facilities.

For the asset management of a water pipe network, it would be necessary to understand the extent of the maintenance cost required for the water pipe network for the future. This study would develop a method to draw the optimum cost required for the maintenance of the water pipe network in waterworks facilities to maintain the aim revenue water ratio and to achieve the target revenue water ratio, considering the water service providers’ waterworks condition and revenue water ratio comprehensively. This study conducted a survey with 96 water service providers as of the early 2015 and developed models to estimate the optimum maintenance cost of the water pipe network, considering the characteristics of the water service providers. Since the correlation coefficient of all the developed models was higher than 0.95, it turned out that it had significant reliability, which was statistically significant. As a result of applying the developed models to the actual water service providers, it was drawn that increasing revenue water ratio to more than a certain level can reduce the maintenance cost of the water pipe network by a great deal. In other words, it is judged that it would be the most efficient to secure the reliability of waterworks management by increasing the short-term revenue water ratio to more than a certain level and gradually increase the revenue water ratio from the long-term perspective. It is expected that the proposed methodology proposed in this study and the results of the study will be used as a basic research for planning the maintenance of water pipe network or establishing a plan for waterworks facilities asset management.

Do automobile test drive reviews really deliver objective information to consumers with scientific expressions? For the analysis, samples were collected from eighteen media outlets -- ten Korean and eight foreign. Collected samples of car reviews were analyzed in terms of sentence unit and classified into two categories: either a sentence with scientific expressions or a sentence with non-scientific expressions. Result showed that car review from 9 medias only had portion of sentence with scientific expressions exceeding 50 percent. Result supports this research's hypothesis that "test drive review of automobile isn't scientific."

Owing to time and cost constraints, new methods that would make it possible to evaluate the safety of the water supply pipeline in a less time- and cost-consuming manner are urgently needed. In response to this exigency, the present study developed a new statistical model to assess the safety of the water supply pipeline using the quantification theory type Ⅱ. In this research, the safety of the water supply pipeline was defined as ‘a possibility of the pipeline failure’. Quantification analysis was conducted on the qualitative data, such as pipe material, coating, and buried condition. The results of analyses demonstrate that the hit ratio of the quantification function amounted to 77.8% of hit ratio, which was a fair value. In addition, all variables that were included in the quantification function were logically valid and demonstrated statistically significant. According to the results derived from the application of the safety evaluation model, the coefficient of determination (R2) between K-region’s water supply pipeline safety and the safety inspection amounted to 0.80. Therefore, these findings provide meaningful insight for the measured values in real applications of the model. The results of the present study can also be meaningfully used in further research on safety evaluation of pipelines, establishing of renewal prioritization, as well as asset management planning of the water supply infrastructure.

목 적: 근시성 난시안에 대하여 핀홀에 의한 시력변화를 연구하였다. 방 법: 안질환이 없고 질환에 의해 시력손상이 없는 20대에서 30대 성인을 대상으로 하였다. 핀홀의 직 경을 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm로 설정하여, 핀홀렌즈 직경에 따른 시력을 비교하였다. 표준 조도 200 lux와 밝은 조도(380~500 lux)에 대하여 조도에 따른 핀홀시력을 검사하였다. 또한 눈의 상태를 나안 상태, 구면 굴절력 가입상태, 등가구면 굴절력 가입 상태, 세 가지로 구분 하여 핀홀시력을 검사하였다. 결 과: 여섯 가지 조건을 비교하였는데, 나안 상태일 때 조도에 상관없이 가장 직경이 작은 0.5 mm에 서 핀홀시력이 상승하였고, 직경이 커짐에 따라 단계적으로 핀홀시력이 감소하였다. 구면 굴절력과 등가 구 면굴절력을 가입하고, 핀홀시력을 비교하였을 때 1.5 mm, 2.0 mm 직경에서 시력상승이 두드러지게 나타났다. 하지만 0.5 mm 직경에서 오히려 시력이 떨어졌다. 단안 보다 양안에서 핀홀시력이 상승하였다. 결 론: 나안 상태에서 초점심도와 피사체심도, 수차 보정에 영향을 받아 직경이 가장 작은 렌즈에서 시 력이 가장 많이 상승하였다. 구면 굴절력과 등가구면 굴절력 가입상태일 때, 망막 위에 후초선과 최소착란원이 놓이게 되면서 나안 상태에 비해 초점심도와 피사체심도의 영향보다는 망막 조도의 영향이 큰 것으로 보인다. 단일 핀홀렌즈에서도 양안가중효과(binocular summation)의 영향이 있는 것으로 판단된다.

Porous metallic glass compact (PMGC) are developed by electro-discharge sintering (EDS) process of gas atomized Zr41.2Ti13.8Cu12.5Ni10Be22.5 metallic glass powder under of 0.2 kJ generated by a 450 μF capacitor being charged to 0.94 kV. Functional iron-oxides are formed and growth on the surface of PMGCs via hydrothermal synthesis. It is carried out at 150oC for 48hr with distilled water of 100 mL containing Fe ions of 0.18 g/L. Consequently, two types of iron oxides with different morphology which are disc-shaped Fe2O3 and needle-shaped Fe3O4 are successfully formed on the surface of the PMGCs. This finding suggests that PMGC witih hydrothermal technique can be attractive for the practical technology as a new area of structural and functional materials. And they provide a promising road map for using the metallic glasses as a potential functional application.

목적: 근시성 난시안에 대해 핀홀효과가 미치는 영향을 연구하고, 핀홀효과를 이용하여 난시안 의 새로운 교정방법으로서의 가능성을 조사하였다. 방법: 안질환을 앓고 있지 않고, 질환에 의해 시력손상이 없는 20~30대 성인을 대상으로 하였 다. 핀홀의 직경을 0.5mm, 1mm, 1.5mm, 2mm로 설정하여, 각 직경별로 핀홀렌즈 시력을 비 교하였다. 조도는 200lux의 표준조도와 밝은 조명(380~500lux)으로 맞춰 조도에 따른 핀홀시 력을 검사하였다. 실험은 나안 상태에서의 핀홀렌즈 검사, 구면렌즈 가입 상태에서의 핀홀렌즈 검사와 등가구면렌즈 가입 상태에서의 핀홀렌즈 검사 세 가지를 실시하여 비교 하였다. 표준 조도(200lux)에서 우안, 좌안, 그리고 양안에 대하여 나안 시력과 각 직경 별 핀홀시력을 비교하여 시력 개선 효과를 분석하였다. 또한 조도의 변화에 따른 효과를 검증하기 위하여 밝 은 조도(380~500lux)에서 같은 실험을 실시하여 분석하였다. 결과: 총 여섯 가지 조건을 비교하였다. 표준조도일 때 나안시력, 구면렌즈 가입, 등가구면 렌 즈를 각각 해당 조건에서 핀홀을 가입하기 전 시력과 핀홀 시력을 직경 별로 비교하였고, 밝은 조도(380~500lux)에서 동일하게 실시하였다. 나안 상태에서 표준조도와 밝은 조도 두 조건 모 두 나안시력보다 핀홀시력이 모든 직경에서 상승하는 것으로 관찰되었다. 특히 0.5mm에서 가 장 높은 시력상승을 보이고, 0.5mm에서 2.0mm까지 단계적으로 시력 상승이 떨어지는 양상을 보였다.구면렌즈와 등가구면렌즈를 가입하고, 핀홀시력을 비교하여 보았을 때 1.5mm와 2.0mm직경에서 시력 상승이 두드러지게 나타났다. 하지만 0.5mm에서 시력 상승 효과가 없거 나 미미하고 오히려 시력이 하락하는 양상을 보였다. 구면렌즈와 등가구면렌즈를 가입했을 때, 검사결과를 조도에 따라 비교하면 표준조도에서 보다 밝은 조도일 때 핀홀효과가 떨어졌다. 결론: 표준조도에서 보다 밝은 조도일 때 구면렌즈와 등가구면 렌즈를 가입했을 때 많은 비교 항목에서 유의하지 않은 것으로 보아, 표준조도에서 핀홀시력의 효과가 높은 것으로 보인다. 나안상태에선 직경이 가장 작은 0.5mm에서 시력 상승 효과가 가장 높은 것은 피사체심도와 초점심도의 깊어짐과 주변광선을 차단하는 효과에 영향을 많이 받는 것으로 분석되었다. 구면 렌즈와 등가구면렌즈에선 직경이 큰 1.5mm나 2mm에서 시력 상승 효과가 큰 것으로 보아 광 량이 줄어듦에 영향을 많이 받는 것으로 판단된다.

In this study, we report the sintering behavior and properties of a Ge2Sb2Te5 alloy powders for use as asputtering target by spark plasma sintering. The effect of various sintering parameters, such as pressure, temperature andtime, on the density and hardness of the target has been investigated in detail. Structural characterization was performedby scanning electron microscopy and X-ray diffraction. Hardness and thermal properties were measured by differentialscanning calorimetry and micro-vickers hardness tester. The density and hardness of the sintered Ge2Sb2Te5 materialswere 5.8976~6.3687 g/cm3 and 32~75 Hv, respectively.

The role of Fatty acid binding protein 4 (FABP4) gene is critical for lipid metabolism and for maintaining homeostasis in adipocytes. Association between Hanwoo carcass traits and FABP4 gene g.7516G>C SNP has been reported previously, however, its association and how does it influence Korean brindle and black cattle has not been demonstrated and established till date. For this purpose, the study was planned to analyze the SNP association (Single Nucleotide Polymorphism) (g.7516G>C) in FABP4 gene and gather genetic information on economic traits of Korean brindle cattle and black cattle. As per sequence of bovine FABP4 gene available (Genbank accession No. NC_007312.4), one pair of primers (5’-ATA TAG TCC ATA GGG TGG CAA AGA-3’ and 5’-AAC CTC TCT TTG AAT TCT CCA TTC T-3’) was designed to amplify a 452bp product of the FABP4 gene including the region of 7417–7868. The SNP, detected by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) methods using restriction enzyme MspA1I, was genotyped in 117 animals of brindle cattle and 24 animals of black cattle population. Statistical analysis revealed that the FABP4 genotype significantly (p<0.05) affect with carcass weight, but there was no significant association with any other economic traits was observed in brindle as well as in black cattle. In conclusion, these results suggested that SNP (g.7516G>C), located in FABP4 gene, could be used as important DNA marker of economic traits in Korean brindle cattle. Furthermore, we suggest that additional samples needs to further analysed to make related data exclusively authentic.

The melanocortin receptor type 4 (MC4R) gene is expressed in the hypothalamus and regulates energy intake and body weight. Recently, it has been reported that obesity and energy balance in human were also regulated by the MC4R gene. Therefore the objective of this study was to identify the polymorphism on the MC4R gene SNP C1786T and its association with economic traits in Korean native cattle (brindle and black cattle) by PCR-RFLP. A total of 125 cattle from the two breeds were tested for economic traits (meat quality index, backfat, thickness, carcass weight, longissimus muscle area and marbling score) and data was analyzed using SAS program. In the results, C allele had highest frequency than G allele frequency in the both breeds and the gene was significantly associated with meat quantity index and backfat thickness in brindle cattle breed. However, in black cattle, the gene was significantly associated with longissimus muscle area (p<0.05). These results suggest that C1786T SNP of the MC4R gene may be useful as a genetic marker for economic traits in the brindle and black cattle.

Al-based alloys have recently attracted considerable interest as structural materials and light weight materials due to their excellent physical and mechanical properties. For the investigation of the potential of Al-based alloys, a surface porous Al88Cu6Si6 eutectic alloy has been fabricated through a chemical leaching process. The formation and microstructure of the surface porous Al88Cu6Si6 eutectic alloy have been investigated using X-ray diffraction and scanning electron microscopy. The Al88Cu6Si6 eutectic alloy is composed of an α-Al dendrite phase and a single eutectic phase of Al2Cu and α-Al. We intended to remove only the α-Al phase and then the Al2Cu phase would form a porous structure on the surface with open pores. Both acidic and alkaline aqueous chemical solutions were used with various concentrations to modify the influence on the microstructure and the overall chemical reaction was carried out for 24 hr. A homogeneous open porous structure on the surface was revealed via selective chemical leaching with a H2SO4 solution. Only the α-Al phase was successfully leached while the morphology of the Al2Cu phase was maintained. The pore size was in a range of 1~5μm and the dealloying depth was nearly 3μm. However, under an alkaline NaOH, aqueous solution, an inhomogeneous porous structure on the surface was formed with a 5 wt% NaOH solution and the morphology of the Al2Cu phase was not preserved. In addition, the sample that was leached by using a 7 wt% NaOH solution crumbled. Al extracted from the Al2Cu phase as α-Al phase was dealloyed, and increasing concentration of NaOH strongly influenced the morphology of the Al2Cu phase and sample statement.

Recently, ultrafine grained (ufg, typically 100 > d > 500 nm) Ti-Fe eutectic materials have been highlighted due to their extraordinarily high strength and good abrasion resistance compared to conventional coarse grained (cg, d > 1μm) materials. However, these materials exhibit limited plastic strain and toughness during room temperature deformation due to highly localized shear strain. Several approaches have been extensively studied to overcome such drawbacks, such as the addition of minor elements (Sn, Nb, Co, etc.). In this paper, we have investigated the influence of the addition of Gd and Y contents (0.3-1.0 at.%) into the binary Ti-Fe eutectic alloy. Gd and Y are chosen due to their immiscibility with Ti. Microstructural investigation reveals that the Gd phase forms in the eutectic matrix and the Gd phase size increases with increasing Gd content. The improvement of the mechanical properties is possibly correlated to the precipitation hardening. On the other hand, in the case of Ti-Fe-Y alloys, with increasing Y contents, primary phases form and lamellar spacing increases compared to the case of the eutectic alloy. Investigation of the mechanical properties reveals that the plasticity of the Ti-Fe-Y alloys is gradually improved, without a reduction of strength. These results suggest that the enhancement of the mechanical properties is closely related to the formation of the primary phase.

Stearoyl-CoA desaturase (SCD1) gene plays important role in fatty acid composition. In order to find marker-assisted selection (MAS) for improving the economic trait, this study was performed to identify the 878T>C single nucleotide polymorphism (SNP) on SCD1 gene. Three genotypes (CC, CT, and TT) were detected in 878T>C SNP of SCD1 gene from 103 Hanwoo population by polymorphism chain reaction-restriction fragment length polymorphism (PCR-RFLP) and economic traits were analyzed by general linear model. The frequency of allele C and T was 0.534 and 0.466, also the genotype frequency of CC, CT and TT was 0.252, 0.563, and 0.184, respectively in the Hanwoo population. The TT genotype of SCD1 gene showed a significantly higher measures (p<0.05) of carcass weight (CW) than CT, CC genotype. No significant association was detected between genotype and other economic trait (marbling, backfat thickness, and longissimus muscle area) in this study. The results revealed that SCD1 gene 878T>C SNP could be useful for effective MAS to increase the economic quality in Hanwoo population.