• 산업경영시스템학회지
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• 제35권1호
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• pp.1-9
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• 2012

It is well known that internet shoppers are very sensitive to sale prices. They visit the various shopping malls and collect the product information including purchase conditions for goods purchase decision-making. Recently the necessity of information support is increasing because of increase of information amount which is necessary and complexity of goods purchase decision-making process. The comparison shopping agent systems have provided price comparison information which is collected from various shopping malls to satisfy internet shoppers information craving. But the frequent price change caused by keen price competition is becoming the primary reason of information quality decline among price comparison sites. RSS which is a family of web feed formats used to publish frequently updated is applied even in on-line shopping malls. This paper develops a RSS product information collection system to get real-time product information. The proposed product information system consists of (1) web crawler module for searching RSS feed shopping malls automatically, (2) RSS reader module for parsing product information from RSS feed file, (3) product DB and (4) product searching module. Performance of the proposed system is higher than the comparison shopping agent systems when it is defined with the volume of collecting product information per unit time.

• Journal of Welding and Joining
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• 제13권4호
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• pp.85-102
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• 1995

Weld quality of GMA welding processes is closely related to arc stability. Although many researches on arc stability have been performed, real-time estimation of arc stability has not been attempted. For instance, Mita proposed a off-line statistical method in which short circuiting and arcing time, and voltage and current wave forms were sampled to assess arc stability. But this method is not suitable to assess arc stability for GMA welder which employ inverter power source due to its controlled current and voltage wave forms. In this paper, the relationship between are stability and wire feed rate fluctuation is analyzed to propose new criterion for inverter power source. When arc voltage and arc current and arcing time are analyzed, we can assess arc stability only for short circuit transfer mode. When wire feed rate is analyzed, we can estimate arc stability udner the condition of spray transfer mode as well. Hence, the wire feed rate is chosen for monitoring process variable to cover possible metal transfer modes in GMAW. Through this research, it has been identified that arc stability in GMA welding processes is closely related to wire fed rate. When inverter power source is used, conventional statistical method of estimating arc stability, such as Mita index, is no longer valid due to its controlled voltage and current wave forms. Arc stability has been also examined in phase plane diagram.

• 한국전자파학회논문지
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• 제16권10호
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• pp.982-988
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• 2005

본 논문에서는 모드 변환기나 필터, 매칭 구조가 모두 연결되어 있는 개구면 안테나의 특성을 예측을 위해 급전 부분에 전이 구조가 붙어 있는 원형 개구면 안테나의 해석적인 산란 해를 제시한다. 개구면의 모양이 원형이기 때문에 길이가 짧고 반지름이 다른 원형 도파관이 연결되어 있는 구조로 모델링하여 안테나를 해석했다. 안테나의 해석에서 급전 도파관과 개구면 사이의 영역은 일반화된 산란 행렬을 이용하여 전기장과 자기장을 나타냈고, 개구면에서 복사되는 전기장과 자기장은 적분 변환을 이용하여 나타내어 전체 구조를 해석했다. 여기서 필요한 산란 행렬과 적분 변환은 모두 해석적으로 계산 가능하고, 엄밀한 해이므로 안테나의 반사 특성, 복사 특성 등을 정확하게 예측 가능하다.

• 한국정밀공학회지
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• 제24권2호
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• pp.95-102
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• 2007

A feeding system is a key component in manufacturing packing boxes such as printing, slotting and gluing. The role of the feeding system is to feed corrugate cardboards which is usually tick and large. So, a special method is necessary to feed corrugate cardboards. This paper suggests a concept and an automatic feeding machine to feed corrugated cardboards using TRIZ, the theory of inventive problem solving. The automatic feeding machine consists of units to regulate the machine according to length and width of corrugated cardboards, a feeding part with a plurality of small rollers, and a sucking part which intensify frictional force between rollers and the lowest feeding cardboard. In particular, the feeding part is composed of an up-and-down motion plate with holes to suck the lowest corrugated cardboard as well as small rolling rollers after stopping in a moment. Thus this machine does not sensitive to size of corrugated cardboards and also can keep feeding accuracy during feeding fast.

• 한국소음진동공학회논문집
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• 제15권3호
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• pp.364-370
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• 2005

The active magnetic bearing (AMB) systems mounted in moving vehicles are exposed to the disturbances due to the base motion, often leading to malfunction or damage as well as inaccurate positioning of the systems. Thus, in the controller design of such AMB systems, robustness to base disturbances becomes an essential requirement. In this study, effective control schemes are proposed for the homo-polar AMB system, which uses permanent magnets for generation of bias magnetic flux, when it is subject to base motion, and its control performance is experimentally evaluated. The base motion of AMB system is modeled as the dynamic disturbances in the gravity and base excitation forces. To effectively compensate for the disturbances, the angle feed-forward controller based on the inverse dynamic model and the acceleration feed-forward controller based on the normalized filtered-X LMS algorithm are proposed. The performance test of the prototype AMB system is carried out, when the system is mounted on rate table. The experimental results show that the performance of the proposed controllers for the AMB system is satisfactory in compensating for the disturbances due to the base motion.

• Asian-Australasian Journal of Animal Sciences
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• 제13권4호
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• pp.511-515
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• 2000

Early weaning is a means of breaking the disease cycle from sow to piglet as well as capitalising on the enormous growth potential of the pig. However, the transition from milk to dry diets results in a growth check. Feeding of supplemental milk, fermented to reduce pH and enterotoxigenic bactetial proliferation, may be a means of gradually weaning pigs on to solid feed. This study involved 216 pigs weaned from the sow at 12 days of age, allocated to groups of 6 males and 6 females per weaner pen and allowed ad libitum access to a pelleted diet. In addition, half the pigs were given supplemental fermented skim milk for the first 8 days after weaning. Feeding supplemental fermented milk increased feed intake (104 vs. 157 g DM/d, p=0.011), average daily gain (-3 vs. 112 g/d, p<0.001) and feed conversion efficiency (0.01 vs. 0.81, p=0.003) over the first 8 days after weaning. The improvements observed in the supplemented pigs continued to be augmented such that, by 42 days of age, the pigs that had received supplemental fermented milk were heavier (9.6 vs. 11.5 kg, p=0.003) than their unsupplemented counterparts. Feeding fermented supplemental milk to early-weaned pigs can improve growth performance in the immediate and subsequent post-weaning period.

• Asian-Australasian Journal of Animal Sciences
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• 제14권4호
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• pp.567-586
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• 2001

Gastrointestinal tract of ruminants as well as monogastric animals are colonised by a variety of microorganisms including bacteria, fungi and protozoa. Gastrointestinal ecosystem, especially the rumen is emerging as an important source for enrichment and natural selection of microbes adapted to specific conditions. It represents a virtually untapped source of novel products (e.g. enzymes, antibiotics, bacteriocins, detoxificants and aromatic compounds) for industrial and therapeutic applications. Several gastrointestinal bacteria and fungi implicated in detoxification of anti-nutritional factors (ANFs) can be modified and manipulated into promising system for detoxifying feed stuffs and enhancing fibre fermentation both naturally by adaptation or through genetic engineering techniques. Intestinal lactobacilli, bifidobacteria and butyrivibrios are being thoroughly investigated and widely recommended as probiotics. Restriction endonucleases and native plasmids, as stable vectors and efficient DNA delivery systems of ruminal and intestinal bacteria, are increasingly recognised as promising tools for genetic manipulation and development of industrially useful recombinant microbes. Enzymes can improve the nutrient availability from feed stuffs, lower feed costs and reduce release of wastes into the environment. Characterization of genes encoding a variety of commercially important enzymes such as cellulases, xylanases, $\beta$-glucanases, pectinases, amylases and phytases will foster the development of more efficacious and viable enzyme supplements and enzyme expression systems for enhancing livestock production.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.719-725
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• 2004

Mesquite or Vilayati babul (Prosopis juliflora) is a drought resistant, evergreen, spiny tree with drooping branches and a deep laterally spreading root system. It grows in semi-arid and arid tracts of tropical and sub-tropical regions of the world and is spreading because the leaves are unpalatable and animals do not digest its seed. The mesquite has become a major nuisance; cutting or pruning its branches to form a canopy would provide shade for travelers, aid harvesting of pods, as well as make available wood for fuel. An average plant starts fruiting by 3-4 years of age and yields annually 10-50 kg pods/ tree, which can be collected from May-June and September-October. Availability of pods worldwide is estimated to be about 2-4 million metric tonnes. Ripe pods are highly palatable; on dry matter basis they contain 12% crude protein, 15% free sugar, a moderate level of digestible crude protein (7% DCP) with a high level of energy (75% TDN). The pods contain low tannin levels below those toxic to animals. Seeds contain 31-37% protein; pods should be finely ground before feeding to facilitate utilization of the seeds. Mesquite pods could replace costlier feed ingredients such as grain and bran contributing 10-50% of the diet. Phosphorus supplements need to be added when mesquite pod, exceeds 20% of animals' diet.

• 한국통신학회논문지
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• 제19권9호
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• pp.1739-1747
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• 1994

본 연구에서는 비균일 배열 안테나의 방사패턴 합성을 위하여 폭이 다른 마이크로스트립 패치 안테나를 급전소자 하는 급전 방식에 대하여 연구하였다. 마이크로스트립 패치 안테나는 전송선로 모델 해석 방법을 적용하여 해석하였으며, 급전소자 간의 급전 선로 길이가 h_g의 정수 배가되면 안테나 각 급전소자의 상대적 전류 비와 입력 어드미턴스의 비가 같음을 유도하였다. 급전소자의 수가 각각 6개와 9개로 제작된 비균일 구형 마이크로스트립 패치 배열 안테나를 실험한 결과 방사패턴에 대한 이론치와 실험치가 잘 일치함을 확인할 수 있다. 따라서 본 연구 결과는 비균일 배열 안테나를 구현하기 위한 급전 방식으로 사용될 수 있을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권7호
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• pp.1048-1060
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• 2005

Dietary acidifiers appear to be a possible alternative to feed antibiotics in order to improve performance of weaning pigs. It is generally known that dietary acidifiers lower gastric pH, resulting in increased activity of proteolytic enzymes, improved protein digestibility and inhibiting the proliferation of pathogenic bacteria in GI tract. It is also hypothesized that acidifiers could be related to reduction of gastric emptying rate, energy source in intestine, chelation of minerals, stimulation of digestive enzymes and intermediate metabolism. However, the exact mode of action still remains questionable. Organic acidifiers have been widely used for weaning pigs' diets for decades and most common organic acidifiers contain fumaric, citric, formic and/or lactic acid. Many researchers have observed that dietary acidifier supplementation improved growth performance and health status in weaning pigs. Recently inorganic acidifiers as well as organic acidifiers have drawn much attention due to improving performance of weaning pigs with a low cost. Several researchers introduced the use of salt form of acidifiers because of convenient application and better effects than pure state acids. However, considerable variations in results of acidifier supplementation have been reported in response of weaning pigs. The inconsistent responses to dietary acidifiers could be explained by feed palatability, sources and composition of diet, supplementation level of acidifier and age of animals.