• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.519-529
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• 2015

The aims of this study were to determine the effects of feeding medium-roasted soybean meal (SBM) and corn dried distiller's grains with solubles (CDDGS) in dairy cows on milk production and income over feed costs. A randomized complete block design experiment was conducted with 24 crossbred multiparous Holstein Friesian dairy cows in early- and mid-lactation. Four dietary treatments were as follows: basal diet without feed substitute (Control), 7.17% dry matter (DM) roasted SBM replaced for concentrate (R-SBM), 11.50% DM CDDGS replaced for concentrate (DDGS), and 3.58% DM roasted SBM plus 5.75% DM CDDGS replaced for concentrate (SB-DG). The roasted SBM was produced using a medium-heated treatment at $100^{\circ}C$ for 180 min. Dry matter intake was not affected by feeding high rumen undegradable protein (RUP) sources, but the replacement of roasted SBM and CDDGS for concentrate significantly improved (p<0.001) RUP intake (0.90, 0.86, and 0.88 kg/d corresponding to R-SBM, DDGS, and SB-DG) compared to the control (0.61 kg/d). Feeding roasted SBM and CDDGS alone or in combination had no significant effect on milk composition of dairy cows (p>0.05), whereas milk yield was significantly increased by 3.08 kg/d in the SB-DG group relative to the control group (p<0.01). Net income was meaningfully increased (p<0.05) from 4th week post feeding, the SB-DG group reached the greatest net income ($3.48/head/d) while the control group had the lowest value ($2.60/head/d). In conclusion, the use of CDDGS alone or in combination with medium-roasted SBM as substitute for concentrate in lactating dairy cattle diet led to improved milk production and net income over feed costs without affecting total dry matter intake and milk composition, while feeding medium-roasted SBM seemed to show intermediate values in almost parameters.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.409-423
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• 2023

In this study, we analyzed how the revenue water ratio(RWR) is affected by changes in conditions of the water supply area, such as the ratio of aging pipes, maintenance conditions, and revenue water. As a result of analyzing the impact of pipe aging and maintenance conditions on the RWR, it was confirmed that the RWR could be decreased if the pipe replacement project to improve the aging pipe ratio was not carried out and proper maintenance costs were not secured. It was also confirmed that an increase in the revenue water could be operated to facilitate the achievement of the project's target RWR. In contrast, a decrease in the revenue water due to a population reduction could affect the failure of the target RWR. In addition to analyzing the causes of variation in the RWR, the calculation of estimated project costs was considered by using leakage reduction instead of RWR from recent RWR improvement project cost data. From this analysis, it was reviewed whether the project costs planned to achieve the target RWR of the RWR improvement project in A city were appropriate. In conclusion, the RWR could be affected by variations in the ratio of aging pipes, maintenance conditions, and revenue water, and it was reasonable to consider not only the construction input but also the input related to RWR improvement, such as leakage reduction, when calculating the project cost.

• Journal of the Korea Concrete Institute
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• v.23 no.1
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• pp.99-107
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• 2011

This study is to performed to find the optimum mix proportion of the high strength and self compacting concrete for the above-ground LNG storage tank construction and field application. If LNG storage tank wall thicknesscan be reduced, the construction cost and quality can be improved by using self-compacting high strength concrete with compressive strength 60~80 MPa. For this purpose, low heat cement (Type IV) and class F fly ash are used in concrete mix to control hydration heat, flowability, and viscosity. Mix design variables of unit water, fly ash replacement ratio, water-binder ratio, and fine aggregate ratio are selected and tested for material properties and manufacturing cost of the concrete. Also, fly ash replacement ratio is considered using confined water ratio test. The test results showed that the optimum mix proportion of the self-compacting high strength concrete characteristics are as follows. 1) In case of the concrete with specified compressive strength of 60 MPa, the optimum mix proportion is fly ash replacement ratio of 20% and water- binder ratio of 27~30%. 2) In case of the concrete with the strength of 80 MPa, the optimum mix proportion is fly ash replacement ratio of 10% and water-binder ratio 25%. But unit water and fine aggregate ratio are 165 $kg/m^3$ and $51{\pm}2%$, respectively, regardless of the traget concrete compressive strength range. Also, test results showed that concrete manufacturing cost of 60 MPa and 80 MPa concrete require additional costs of 14~22% and 33%, respectively, compared to the manufacturing cost of 40 MPa concrete. Therefore, application of the self-compacting high strength concrete has proven to be economical in the perspective of the material cost, quality control, and site management.

• Journal of mucopolysaccharidosis and rare diseases
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• v.3 no.1
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• pp.9-13
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• 2017

Tandem mass spectrometry and other new technologies for the multiplex and quantitative analysis of dried blood spots have emerged as powerful techniques for the early screening and assessment of newborns for lysosomal storage diseases (LSDs). Screening newborns for these diseases is important, since treatment options, including enzyme replacement therapy or hematopoietic transplantation, are available for some LSDs, such as infant-onset Pompe disease, Fabry disease, some types of mucopolysaccharidoses (MPSs), and Krabbe disease. For these diseases, early initiation of treatment, before symptoms worsen, often leads to better clinical outcomes. Several problems, however, are associated with newborn screening for LSDs, including the development of accurate test methods to reduce low false-positive rates and treatment guidelines for late-onset or mild disease variants, the high costs associated with multiplex assays, and ethical issues. In this review, we discuss the history, current status, and ethical problems associated with the newborn screening for LSDs, including MPSs.

• Journal of Korean Society for Quality Management
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• v.25 no.3
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• pp.86-95
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• 1997

This paper considers a repairable system, which is maintained preventively at periodic times and is minimally repaired at each failure. Most preventive maintenance policies for such repairable systems assume that the cost of minimal repair is constant regardless of its age at failure. However, it is more practical to consider the situations where the cost of minimal repair is dependent not only on its age at failue, but also on the number of preventive maintenance carried out prior to its failure. We consider the preventive maintenance carried out prior to its failure. We consider the preventive maintenance policy with age-dependent minimal repair cost. The optimal policies which minimize the expected cost rate over an infinite time span are discussed. We obtain the optimal period and number of preventive maintenance prior to replacement of the system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.35-44
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• 2014

This study was to secure the safety of poor appearance distribution concrete poles effectively and to reduce the replacement costs of them by developing a soundness evaluation index. The researcher of this study investigated poor appearance types of concrete pole, collected 53 of test samples, and tested pole strength. As a result of strength test, only 17 percent of poor appearance concrete poles were below 2.0 of safety factor spec. As results of multiple regression analysis, it is verified that surface air void, horizontal crack, net-shaped crack, elapsed year, vertical crack, and deterioration in concrete compressive strength have statistically negative effects on safety factor of concrete poles in a significant level. The researcher set up a soundness evaluation index by using multiple regression equation, and suggested that poor appearance concrete poles should be replaced or reinforced only in case of soundness evaluation score of 150 or above.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.2
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• pp.47-65
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• 1998

We consider a multiperiod capacity planning problem for determining a mix of flexible and dedicated capacities under budget restriction. These capacities are controlled by purchasing flexible machines and/or new dedicated machines and disposing old dedicated machines. Acquisition and replacement schedules are determined and operations are assigned to the flexible or dedicated machines for the objective of minimizing the sum of discounted costs of acquisition and operation of flexible machines, new dedicated machines, and old dedicated machines. In this research, the Problem is formulated as a mixed integer linear Program and solved by a Lagrangian relaxation approach. A subgradient optimization method is employed to obtain lower bounds and a multiplier adjustment method is devised to improve the bounds. We develop a linear programming based Lagrangian heuristic algorithm to find a good feasible solution of the original problem. Results of tests on randomly generated test problems show that the algorithm gives relatively good solutions in a reasonable amount of computation time.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.1
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• pp.55-62
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• 1995

This paper compares the two policies which are unsed in Korean electronic appliance industry. Policy I is a general warranty policy under which all of failures during warrenty period (12 months) are repaired without charge. Policy II was proposed recently by a company. Under Policy II, when the product fails until a certain times(6 months), the failed product will be replaced by the new product and all other failures from the certain time to the warrenty period (24 months) will be repaired free. We obtain the expected total warranty costs per product and necessary conditions under which the Policy II has a meaning in economic point of view without or with discount rate. Some numericla examples are considered.

• Journal of the Korean Professional Engineers Association
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• v.42 no.5
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• pp.41-45
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• 2009

The last century of lighting has been dominated by incandescent, fluorescent and high-intensity discharge(HID)light sources. In the late 1970's, after green LEDs were invented, Dr. Ching Tang at Eastman Kodak discovered that sending an electrical impulse through carbon compound caused such material glow. Present day LED commercial packages have reached 100 lm/W, comparable to the efficacies of fluorescent and certain HID lamps. LED products available today are market as "Green-Industry" but actually low light output compared to typical light sources. The combination of high price and low light output make them a poor replacement for current technology. It is very important to compare new LED products to the most efficient conventional technology that could be used for any specific application. As LED technology advances, costs decrease, and efficiency improves, LEDs will build market share in the general illumination market.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.58
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• pp.17-27
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• 2000

In FMS where tool movement policy is adopted, a mathematical model has been developed which determines the selection of a tool type for each operation and tool loading-part assignment simultaneouly. The objective is to minimize the total cost of operation including machining time cost, tool cost, tool replacement and loading time cost, and tool change time cost. Due to the complexity of the problem, an approximate solution procedure has been developed utilizing the special structure of the model. Tool selection was determined first to allocate one tool type to each operation considering more than one tool type alternatives for each operation. Tool loading-part assignment was determined to minimize tile total number of tool changes due to part mix based on the tool selection.