• Korean Journal of Animal Reproduction
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• v.19 no.3
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• pp.161-169
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• 1995

To investigate the metabolism of various substrates in preimplantation bovine embryos, uptake of glucose and pyruvate, and lactate production were measured in single IVF-derived bovine embryos by a non-invasive method. When the embryos were incubated for 5 h in culture medium supplemented with 1 mM glucose and 0.4mM pyruvate as substrates at each developmental stage, glucose uptake was increased with more advanced developmental stages while pyruvate uptake was decreased. Total lactate producton of 2-cell embryos was significantly higher than that of blastocysts (p<0.05). Both of glucose uptake and lactate production in normal morulae produced in vitro was significantly high compared to the degenerated embryos(p<0.05). The results obtained in the study suggest that pyruvate as an exogenous substrate may be support in bovine embryos until 8-cell stage, whereas glucose may be effective as an energy source after morula stage. In addition, it was proven thatlactate was not effective as an energy source in preimplantation development of IVF-derived bovine embryos.

• Journal of Korean Society for Quality Management
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• v.24 no.1
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• pp.20-31
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• 1996

A pure zero-one integer program is formulated for determining where to assign the inspection stations in a multi-stage production system. The objective fuction is formulated to minimize the overall inspection costs. One of the major characteristics of this system is that an assigned inspection station is to inspect only the items produced in previous manufacturing stages. Each inspection station can be assigned to any possible inspection stage between two manufacturing stages. Error-free and screening inspection policy is assumed in this system and the defective items found in any inspection station will be reworked at once. The integer programming model presented in this paper has the advantages in the ease of modeling and modifiing as compared with the existing dymanamic programming methods. The solutions of the model can be easily obtained by the commercially available softwares like LINDO and GAMS.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.2
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• pp.168-173
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• 2006

This paper proposes an auto-focusing method for production of compact camera module (CCM). The CCM test handlers are mainly used in the final CCM production stage to test and adjust the lens focus of CCMs. To improve the productivity of CCM test handlers, we propose the auto-focusing method adjusting the lens focus efficiently. The max-min-difference (MMD) method is newly developed to compute the focus value efficiently, and two-stage searching method is also developed to find the best focus position quickly. Experimental results are presented to verify the usefulness of proposed method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.167-174
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• 1995

The Dynamic programming method are developed for determining where to assign the inspection efforts in serial multi-stage production systems. The objective function is formulated to minimize the inspection and repairing costs. One of the major assumptions in this systems is that every assigned inspection stations should inspect the only items produced in manufacturing stages after the previous inspction station. The inspection stations can be assigned at every possible inspection stage after the manufacturing stages. Two type error is considered and screening inspection policy is assumed in this system and the defective items detected in tile inspection stations will be repaired or scraped by the defective types.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.31-37
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• 2009

Low-pressure membrane processes have been extensively expanded their applications to drinking water production in a few decades. As a capacity of a membrane plant becomes greater in recent years, proper methods to increase water production as well as to treat residuals have drawn great attention. A possible treatment option for the better water production is to apply a dual membrane system. The second stage microfiltration was installed and operated for approximately six months. The residuals from the two stage microfiltration were investigated to learn their characteristics in settling and dewatering processes. The settlability of the membrane residuals were greatest at the SS concentration of approximately 15000mg/L. The proper dose of the polyelectrolytes for filterability were obtained in the range of 0.5~1%. In the dosage range, the water contents of the membrane residuals were greater but the SRF were lower than the residual from the conventional process.

• Journal of Aquaculture
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• v.20 no.3
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• pp.194-198
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• 2007

Reproductive traits of Palaemon gravieri such as embryo size, number of embryo (fecundity), incubation period, larval development mode, larval development period, larval survival and larval growth were described and compared to analyze the correlation among those traits. Embryo volume is a primary factor determining other ensuing reproductive features. Egg volume was $0.042mm^3$ in the first developmental stage. Embryo volume in P. gravieri was comparatively small which is indicative of great number of embryo (y = 3.0161x + 0.0185 $R^2$ = 0.74 positive isometric relationship) and relatively long incubation period. Larvae survived from zoea 1 to post-larvae and it took 45 days at $22^{\circ}C$. Survival rate of the larvae was rather great in the early stage and thereafter steadily decreased. Daily growth rate of larvae in P. gravieri at $22^{\circ}C$ was 0.0195 mm on average. They grew steadily as time went by. Incubation period was between 10-14 days at $22^{\circ}C$. Larval development mode was almost complete planktotrophic. PNR (point of no return) appeared to be the third day on average. Survival rate of larvae without feeding declined rapidly between 3 and 4 days. Larval development period and stage frequency were 23-30 days and 11 stages which imply prolonged larval period and high mortality. The pattern of brood production followed fast successive parturial pattern. Most ovigerous female had mature ovary when they performed parturial molt soon after hatching (larval release).

• Journal of Korean Society of Archives and Records Management
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• v.18 no.4
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• pp.25-43
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• 2018

As nonexisting information affects actual information release rate, the study noted that the absence of records leads to the "nonexistence of information." Therefore, in this research, it was argued that records management should be thoroughly controlled from the stage of record production to solve problems such as the loss/damage/neglect/destruction/misclassification/ reduction of preservation periods and more. Through the management from the production stage, it is expected that the nonexistence of information problem will not occur and can be used as a tool for a demonstration of why the nonexistence of information exists even if such information occurs.

• The Journal of Fisheries Business Administration
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• v.52 no.3
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• pp.39-55
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• 2021

The purpose of this paper is to confirm the trend of inland water fish farming in North Korea and to suggest a plan for inter-Korean cooperation. North Korea's inland water fish farming laid the foundation for production in the 1950s and 1960s, and production facilities were expanded until 1980. In the midst of the severe economic crisis in the 1990s, North Korea paid attention to inland water fish farming as an alternative to food production. The military took the lead in expanding the aquaculture industry and catfish farming was encouraged. In the Kim Jong-un era, North Korea's inland fish farming continues the tradition of catfish farming and promotes a policy of expanding inland cage farming. This study comprehensively reviewed recent inter-Korean relations, North Korea's food crisis and acceptability, and UN sanctions. As a result, inland water fish farming is the most promising field for inter-Korean cooperation in the field of fisheries. In the initial stage of inter-Korean cooperation in the field of inland water fish farming, humanitarian aid projects such as feed and seed support can be promoted. In the stage of expanding inter-Korean cooperation, knowledge sharing program and materials and facilities support projects can be promoted. Development cooperation and direct private investment are possible at the full-scale stage.

• Journal of the Korean Operations Research and Management Science Society
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• v.4 no.1
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• pp.25-31
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• 1979

We consider the optimal ordering policy for a single-product two-stage inventory system where the main assumptions are as follows: (i) constant continuous demand only at stage 2, (ii) constant input (production) rate at stage 1, (iii) instantaneous delivery (transportation) from stage 1 to stage 2, (iv) backlogging is allowed only at stage 2, (v) an infinite planning horizon. Costs considered are ordering and linear holding costs at both stages, and linear shortage cost only at stages 2. By solving 9 different case problems, we have observed the general from of the optimal ordering policies for our model which minimizes the total cost per unit time. It is noticeable from this observation that the questionable but more often than not adopted assumption by many authors in determining the optimal potimal policy for multistage inventory systems, that the ordering (lot) sizes at each stage remain constant thruout the planning horizon, is not valid.

• Korean Journal of Poultry Science
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• v.21 no.4
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• pp.257-266
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• 1994

Three protein feeding systems for egg-type pullets involving conventional step-down protein 18-15-12%), step-up protein(12-15-18%) and single-stage low protein (13-13-13%) with an iso-energy level of 2,900 ME kcal /kg were compared to examine the effect on pullet growth and subsequent laying performance. During the growing period, pullets subjected to the step-up and single-stage low protein feeding systems were lighter in body weight and consumed less feed and netabolizable energy than those on the conventional step-down protein feeding system(P<0.05). 3ut the pullets on the step-up protein diet consumed more protein, and those on the single-stage low protein diet consumed less protein than those on the step-down protein diet(P<0.05). Also, he feed cost was less in pullets on the single-stage low protein diet than in those on the other systems(P<0.05). During the laying period, sexual maturity was later in hens reared on the step-up and single-stage low protein diets than in those on the step-down protein diet(P<0.05), however, average hen-day egg production and egg weight were not significantly affected by the protein feeding systems in the growing period. Daily feed intake and feed required per egg were significantly reduced in hens on the single-stage low protein diet compared to those on conventional protein feeding system(P<0.05). It was concluded that the 13% single-stage low protein feeding system produced smaller pullets with less feed, energy, protein, and feed cost during the growing period, and hens reared on that system consumed less feed during the laying period without any impairment of production compared to the conventional rearing system.