• Animal Bioscience
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• v.34 no.1
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• pp.102-108
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• 2021

Objective: The objective of this study was to investigate the influence of dietary lead (Pb) supplementation and feeding period on growth performance, organ weight, and Pb accumulation in pigs. Methods: In a 56-day feeding experiment, a total of 48 barrows with initial body weight 10.4±0.6 kg were allotted to 2 dietary treatments (0 and 200 mg/kg of supplemental Pb) in a completely randomized design with 6 replicates. Body weight and feed intake were recorded to calculate growth performance. At the end of each 14 day-period (on days 14, 28, 42, and 56), an animal was randomly selected from each pen and slaughtered to collect blood samples, hair samples, left 5th rib, heart, liver, kidneys, lungs, and longissimus dorsi muscle samples. Results: Average daily gain and average daily feed intake were reduced (p<0.05) by supplemental Pb during the day 42 to 56. Relative kidney weight to body weight was linearly increased with increasing feeding period in pigs fed the Pb-supplemented diet, but not in pigs fed the control diet (p<0.05). The Pb concentrations in hair, left 5th rib, kidneys, and lungs were linearly increased with longer feeding period in pigs fed the Pb-supplemented diet, but not in pigs fed the control diet (p<0.01). Conclusion: Dietary Pb supplementation caused growth retardation and Pb accumulation in most organs, particularly in hair, bone, and kidneys in a time-dependent manner.

• Journal of Korea Water Resources Association
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• v.54 no.12
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• pp.1285-1294
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• 2021

In recent years, as rainfall is concentrated and rainfall intensity increases worldwide due to climate change, the scale of flood damage is increasing. Rainfall of a previously unobserved magnitude falls, and the rainy season lasts for a long time on record. In particular, these damages are concentrated in ASEAN countries, and at least 20 million people among ASEAN countries are affected by frequent flooding due to recent sea level rise, typhoons and torrential rain. Korea supports the domestic flood warning system to ASEAN countries through various ODA projects, but the communication network is unstable, so there is a limit to the central control method alone. Therefore, in this study, an artificial intelligence-based flood prediction model was developed to develop an observation station that can observe water level and rainfall, and even predict and warn floods at once at one observation station. Training, validation and testing were carried out for 0.5, 1, 2, 3, and 6 hours of lead time using the rainfall and water level observation data in 10-minute units from 2009 to 2020 at Junjukbi-bridge station of Seolma stream. LSTM was applied to artificial intelligence algorithm. As a result of the study, it showed excellent results in model fit and error for all lead time. In the case of a short arrival time due to a small watershed and a large watershed slope such as Seolma stream, a lead time of 1 hour will show very good prediction results. In addition, it is expected that a longer lead time is possible depending on the size and slope of the watershed.

• 연구논문집
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• s.27
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• pp.167-174
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• 1997

Point of Production/Manufacturing Execution Systems are an essential component of operations in today's competitive business environments, which require greater production efficiency and effectiveness. POP/MES focuses on the valuing-adding processes, helping to reduce manufacturing cycle time, improve product quality, reduce WIP, reduce or eliminate paperwork between shifts, reduce lead time and empowering plant operations staff. In this paper, we implement POP/MES to manage real-time plant floor data which is gathered by I/O server into database management system. I/O server is a software allows data exchange between factory real-time database and several hardware devices such as PLC, DCS, robot and sensor through ethernet TCP/IP protocol.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.4
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• pp.37-50
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• 2012

The existing DEA models have been devoted to evaluate relative efficiency of DMUs based on multiple input and output factors of a same period. However, a certain kind of lead time can be required to produce outputs using inputs in an organization. R&D evaluation is a typical area with this kinds of time lag. Thus, the purpose of this paper is to develop a new DEA model to deal with time lag effect in performance evaluation. The proposed model is to find relative efficiency of each DMU for each period considering the time lag effect. A case example using a real data set is also given to show the usage or implication of the suggested model. The results are compared with the ones of the CCR model and the multi-periods input model.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.674-679
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• 1994

Acoustic signal such as speech and scattered sound, are generally a nonstationary process whose frequency contents vary at any instant of time. For time-varying signal, whether a nonstationary or a deterministic transient signal, a traditional frequency domain representation does not reveal the contents of signal characteristics and may lead to erroneous results such as the loss of desired characteristics features or the mis-interpretation for a wrong conclusion. A time-frequency domain representation is needed to characterize such signatures. Pseudo Wigner-Ville distribution (PWVD) is ideally suited for portraying nonstationary signal time-frequency domain and carried out by adapting the fast Fourier transform algorithm. In this paper, the important properties of PWVD were investigated using both stationary and nonstationry signatures by numerical examples PWVD was applied to acoustic sigtnatures to demonstrate its application for time-ferquency domain analysis.

• Journal of IKEEE
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• v.25 no.2
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• pp.315-321
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• 2021

In this paper, we have developed the multiple channel measurement system for IC Socket Test. The one can test the current-voltage measurements for pitting the several device specification, which analyze the thin current from several ㎂ to 5A with very low resistor mΩ. The increasement of the IC socket channel with lead pitch under 0.25 mm be need to perform several functions, concurrently. The system to perform these functions be designed to integrate several SMU(source measure unit) on board. So, we can reduce the 2 minutes test time per channel point to 40 sec, with daisy chain test method. Using by graphic interface, I-V curve mode and data logging technologies, we can implement the test flow methods and can make economies the time and cost.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.275-285
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• 2004

This paper aims to construct an effective decision making model on selection of product design in product development using fuzzy AHP technique. It is expected that this paper contributes to enhancement of company's market competitiveness by shortening the lead time to develop a new product and minimize initial investment. The proposed model using fuzzy AHP enables quick decision making by integrating and analyzing all customer requirements related to a product. In addition, it can deal with vagueness and uncertainty of decision making process using fuzzy set theory. Decision making processes for evaluating the best selection of product design are also constructed to describe the exact concept of development. A tennis racket is shown as an example. The proposed model is expected to be applied in various fields of managerial decision making processes as well as of product development process.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.117-125
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• 2010

Development of digital media and computer graphics related research had changed the overall stream of cultural art and our daily life, as well as its development also had an effect on a fresh and exciting area of cultural arts such as the new media art, interactive art and real-time performing. In this paper, we used emotional expression techniques that they lead audiences on the process of natural communication by combining the particle system of computer graphics with performance based screen art. In this paper, we used emotional expression techniques that they lead audiences on the process of natural communication by combining the particle system of computer graphics with performance based screen art. Namely, by capturing the creation and location speed of particle which is synchronized between the sound, behavior and particles, performance based screen art as the form of the experimental structure in which is combined with scientific technology and art is therefore proposed.

• Journal of Welding and Joining
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• v.22 no.2
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• pp.46-50
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• 2004

In today's highly competitive marketplace, it is of great significance for the manufacturing industry to reduce lead-time and costs fur the product development. Since first emerged in 1986, Rapid Prototyping (RP) technology has helped successfully to reduce time and costs. Recently, RP using functional materials such as metal has been researched. However RP using the molten metal has been struggling to resolve several drawbacks, such as dimensional inaccuracy, poor surface finish, post finishing, etc., that originate primarily from the overall deposition of molten metal for each layer. So, the purpose of this study is to develop a new RP technique using sheet metal and projection welding for reducing several drawbacks in occurring RP using molten metal. Also tensile and bending specimens were made by the developed RP process using projection welding and were verified.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.331-333
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• 2001

The flooded type battery is used for solar lighting system. Because the characteristic of flooded type battery is the short life time, the maintenance cost is high. So the using floe fed type battery in this system is inappropriate. The valve regulated lead acid batter(VRLA) is the maintenance free and cycle service purpose. This paper presents the development of control system and monitoring system to applied VRLA battery for maintenance free and long life time in system.