• Korean Management Science Review
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• v.10 no.2
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• pp.61-77
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• 1993

This paper involves a study of developing the production scheduling system in a general job shop type mechanical factory. We consider realistic situations in the job-shop environments, such as alternative machines for operation, the new kinds of processes, the machining center with the plural pallet, the operational situation of each machine during the scheduling period, occurings of urgent orders and machine breakdowns. We also propose the methodology of re-schedule. It is very fast and acceptable for real time production control system. These all functions are implemented on IBM PC and program source is written in PASCAL language.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.85-94
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• 2000

This paper deals with the selection of a proper dispatching rule for an one-process Job scheduling that follows a particular distribution of an order production. That is, it makes a distribution on an order per unit period and applies to simulation model that uses it. This study consists of two purposes either seeks adequately production scheduling using priority rule or seeks extension of the facilities that increase current production efficiency through computer simulation in scheduling.

• Journal of the Korean Operations Research and Management Science Society
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• v.12 no.2
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• pp.5-20
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• 1987

This paper addresses sensitivity analysis for a deterministic multi-period production and inventory model. The model assumes a piecewise linear cost structure, but permits backlogging of unsatisfied demand. Our approach to sensitivity analysis here can be divided into two basic steps; (1) to find the optimal production policy through a forward dynamic programming algorithm similar to the backward version of Zangwill [1966] and (2) to apply the penalty network approach by the author [1986] in order to derive sensitivity ranges for various model parameters. Computational aspects are discussed and topics of further research are suggested.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.17-24
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• 1997

This research suggests an approach to reduce the physical distribution cost of production by analyzing data from real situations. The proposed approach re-layouts facilities according to the SLP(Systematic Layout Planning) method. An application result showed that the production lead time was reduced by 24% and the payoff period for facility re-layout was about ten months.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.372-378
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• 2010

The objective of this study was to investigate the effects of an oral drench of propylene glycol (PG) on milk production, serum metabolites and reproductive performance during the transition period of animals. Twenty-four 2-3 multiparous Holstein cows (average body weight 565 kg, body condition score about 3.6, at the $9^{th}$ month of gestation) were selected, blocked, and then randomly assigned into a PG and a control group. The control and the PG group cows were orally drenched with water or 50 ml sugarcane molasses mixed with 500 ml PG from 7 days pre-partum to 30 days post-partum, respectively. Experimental results indicated that the oral drench PG had no effect on dry matter intake (DMI). The milk yield of the PG group was significantly higher than that of the control group (p<0.05), whereas milk fat content, milk protein and somatic cell counts (SCC) were not significantly different between groups. Concentration of plasma glucose in the PG group was significantly higher than that of the control group (p<0.05). Conversely, the concentrations of non-esterified fatty acids (NEFA), and blood urea nitrogen (BUN) in the PG group were lower than those of the control group (p<0.05). Concentrations of insulin and ketone bodies were not significantly difference between groups. Body condition score (BCS) in the PG group was significantly higher than that of the control group (p<0.05). In reproductive performance there was no difference between groups. The experimental results indicate that supplementation of PG during the transition period of dairy cows can supply energy rapidly, resulting in reduced catabolism of body tissue and increased milk yield.

• International Journal of Industrial Entomology and Biomaterials
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• v.47 no.1
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• pp.44-50
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• 2023

The Daehwangjam has excellent marketability and quality. However, precise silkworm breeding data on the recent high-temperature environment is not enough collected, and it is necessary to check whether stable Daewhangjam silkworm egg production was possible in poor environments. In this study, the timing of metamorphosis of the Daewhangjam parents Jam323 and Jam324 silkworms, in an optimal condition and a general condition similar to breeding grounds, was investigated to confirm that appropriate mating was achieved. Surprisingly, a number of female moths were discarded due to the metamorphosis of Jam324 female moths much earlier than Jam323 male moths in either an optimal or a general condition. To improve this, during the Jam324 female pupation period, the mild low-temperature of 15℃ was treated for the pupation period to delay the metamorphosis into female moths. Depending on the treatment period, the metamorphosis of the female pupa was delayed by more than 4 days, allowing normal mating with the Jam323 male moth. The eye pigments in a pupa also slowly accumulated in these treatments. In order to discover the side effects of low-temperature treatments, the voltinism of the Daewhangjam eggs was investigated, but most of them remained univoltine. Taken together, the low-temperature treatment during the female pupation period made it possible to use Jam324 female moths that were should be discarded, which means that stable and efficient management of Daewhangjam egg production is possible.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.968-973
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• 2005

The purpose of this study is to clarify the reality of labor and capital productivity in the construction industry through an industry-level approach and to analyze the relationship between labor and capital productivity using a Cobb-Douglas production function. According to the research results, the construction industry has shown a very high capital productivity, while labor productivity has kept up a low level during the 1980s and 1990s. The reason was because of the lack of skillful construction workers and the decrease of capital. Meanwhile, the construction productivity has greatly increased since 2000 when there was no change in wages. This was because of a large inflow of low-wage foreign workers while the amount of value added has dramatically increased due to the liberalized sale price of apartment buildings. According to the analysis by the Cobb-Douglas production function, the elasticity coefficient of V/L to K/L in the construction industry had decreased from 1.1663 in the 1^st period(1971-1988) to 0.4465 in the 2^nd period(1989-1997), and to 0.1664 in the 3^rd period(1998-2003). Such a result means that the allocation of labor has gradually increased while the allocation of capital has decreased. Moreover there was a big increase in allocation of labor after 1998 due to the excessive deterioration of capital. In conclusion, in order to raise the construction productivity and to avoid labor-intensive production methods, investment for capital should be more increased. In particular, new machinery and equipment that can actually substitute human labor in construction sites should be more developed and applied to construction sites.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.981-985
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• 2003

The changes of component through simultaneous production of bacterial cellulose and vinegars by G. persimmonis KJ145$^{T}$ were examined. As a results, pH was decreased to 3.22 at 8 days of fermentation and total acidity showed 4.66 which was the highest at the 8 days of fermentation. Brix didn't show any changes during the fermentation period. Free sugars of fermentation broth were consist of fructose, glucose and sucrose. The fructose concentration of fermentation broth was maintained highly during fermentation period (until the final 10 days) without a remarkable decrease. The cell growth of G. persimmonis KJ145$^{T}$ was very rapidly increased from the 2 days of fermentation and increased most at the 4 days of fermentation. The productivity of bacterial cellulose was increased in proportion to the fermentation period. Malic acid, succinic acid and oxalic acid were detected as a organic acid of vinegar. The concentration of acetic acid was rapidly increased from the 2 days and reached highest concentration at 8 days. In conclusion, the results indicated that the 8 days was the optimal fermentation period to produce the bacterial cellulose and vinegar by G. persimmonis KJ145$^{T}$ simultaneously.

• Architectural research
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• v.7 no.2
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• pp.91-96
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• 2005

The purpose of this study is to clarify the reality of labor and capital productivity in the construction industry through an industry-level approach and to analyze the relationship between labor and capital productivity using a Cobb-Douglas production function. According to the research results, the construction industry has shown a very high capital productivity, while labor productivity has kept up a low level during the 1980s and 1990s. The reason was because of the lack of skillful construction workers and the decrease of capital. Meanwhile, the construction productivity has greatly increased since 2000 when there was no change in wages. This was because of a large inflow of low-wage foreign workers while the amount of value added has dramatically increased due to the liberalized sale price of apartment buildings. According to the analysis by the Cobb-Douglas production function, the elasticity coefficient of V/L to K/L in the construction industry had decreased from 1.1663 in the $1^{st}$ period(1971-1988) to 0.4465 in the $2^{nd}$ period(1989-1997), and to 0.1664 in the $3^{rd}$ period(1998-2003). Such a result means that the allocation of labor has gradually increased while the allocation of capital has decreased. Moreover there was a big increase in allocation of labor after 1998 due to the excessive deterioration of capital. In conclusion, in order to raise the construction productivity and to avoid labor-intensive production methods, investment for capital should be more increased. In particular, new machinery and equipment that can actually substitute human labor in construction sites should be more developed and applied to construction sites.

• Korean Journal of Poultry Science
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• v.26 no.4
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• pp.261-265
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• 1999

The objective of this experiment was to investigate the effect of feeding Angelica gigas Nakai by-products on performance and meat quality of Korean native chicks(KNC). Five hundred forty KNC were placed into 0, 0.2, and 0.4% Angelica gigas supplements with four replications between males and females. Weight gain, feed conversion ratio(FCR), breast meat lipid, fatty acid and protein contents were measured from 17 to 20 weeks old. Egg production, feed intake and FCR were examined from 22 to 29 weeks at four weeks at four weeks intervals. Basal diets based on corn and soybean meal contained 15% crude protein and 2,850㎉/kg ME for the growing period, 16.5% and 2,800㎉/kg for the laying period. Experiments were designed in a one way analysis. Weight gain of female chicks fed 0.2% Angelica gigas by-products increased significantly compared to that of other treatments for the growing period, but was not consistency in male groups. Moisture, protein, fat content were not statistically different among all treatments. Fatty acid composition(C16:0, C18:0) of chicks fed 0.2% Angelica gigas by-products was higher than other treatments. In laying period, hens fed 0.2 or 0.4% Angelica gigas Nakai by-products seemed to increase the egg production and significantly improved FCR compared to that of control(P〈0.05). Birds fed 0.4% treatment showed significantly the lowest feed intake and FCR of all treatments(P〈0.05). The results of these studies indicated that dietary supplemental Angelica gigas by-products may have a role to improve the performance of KNC.