• Journal of Computational Design and Engineering
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• 제3권2호
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• pp.140-150
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• 2016

Normally all manufacturing and fabrication processes introduce residual stresses in a component. These stresses exist even after all service or external loads have been removed. Residual stresses have been studied elaborately in the past and even in depth research have been done to determine their magnitude and distribution during different manufacturing processes. But very few works have dealt with the study of residual stresses formation during the casting process. Even though these stresses are less in magnitude, they still result in crack formation and subsequent failure in later phases of the component usage. In this work, the residual stresses developed in a shifter during casting process are first determined by finite element analysis using ANSYS(R) Mechanical APDL, Release 12.0 software. Initially the analysis was done on a simple block to determine the optimum element size and boundary conditions. With these values, the actual shifter component was analyzed. All these simulations are done in an uncoupled thermal and structural environment. The results showed the areas of maximum residual stress. This was followed by the geometrical optimization of the cast part for minimum residual stresses. The resulting shape gave lesser and more evenly distributed residual stresses. Crack compliance method was used to experimentally determine the residual stresses in the modified cast part. The results obtained from the measurements are verified by finite element analysis findings.

• 펄프종이기술
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• 제47권4호
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• pp.177-186
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• 2015

Until Mandelbrot introduced the concept of fractal geometry and fractal dimension in early 1970s, it has been generally considered that the geometry of nature should be too complex and irregular to describe analytically or mathematically. Here fractal dimension indicates a non-integer number such as 0.5, 1.5, or 2.5 instead of only integers used in the traditional Euclidean geometry, i.e., 0 for point, 1 for line, 2 for area, and 3 for volume. Since his pioneering work on fractal geometry, the geometry of nature has been found fractal. Mandelbrot introduced the concept of fractal geometry. For example, fractal geometry has been found in mountains, coastlines, clouds, lightning, earthquakes, turbulence, trees and plants. Even human organs are found to be fractal. This suggests that the fractal geometry should be the law for Nature rather than the exception. Fractal geometry has a hierarchical structure consisting of the elements having the same shape, but the different sizes from the largest to the smallest. Thus, fractal geometry can be characterized by the similarity and hierarchical structure. A process requires driving energy to proceed. Otherwise, the process would stop. A hierarchical structure is considered ideal to generate such driving force. This explains why natural process or phenomena such as lightning, thunderstorm, earth quakes, and turbulence has fractal geometry. It would not be surprising to find that even the human organs such as the brain, the lung, and the circulatory system have fractal geometry. Until now, a normal frequency distribution (or Gaussian frequency distribution) has been commonly used to describe frequencies of an object. However, a log-normal frequency distribution has been most frequently found in natural phenomena and chemical processes such as corrosion and coagulation. It can be mathematically shown that if an object has a log-normal frequency distribution, it has fractal geometry. In other words, these two go hand in hand. Lastly, applying fractal principles is discussed, focusing on pulp and paper industry. The principles should be applicable to characterizing surface roughness, particle size distributions, and formation. They should be also applicable to wet-end chemistry for ideal mixing, felt and fabric design for papermaking process, dewatering, drying, creping, and post-converting such as laminating, embossing, and printing.

• Journal of Information Science Theory and Practice
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• 제9권1호
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• pp.24-34
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• 2021

The popularity of social networking sites (SNS) has facilitated communication between users. The usage of SNS helps users in their daily life in various ways such as sharing of opinions, keeping in touch with old friends, making new friends, and getting information. However, some users misuse SNS to belittle or hurt others using profanities, which is typical in cyberbullying incidents. Thus, in this study, we aim to identify profane words from the ASKfm corpus to analyze the profane word distribution across four different roles involved in cyberbullying based on lexicon dictionary. These four roles are: harasser, victim, bystander that assists the bully, and bystander that defends the victim. Evaluation in this study focused on occurrences of the profane word for each role from the corpus. The top 10 common words used in the corpus are also identified and represented in a graph. Results from the analysis show that these four roles used profane words in their conversation with different weightage and distribution, even though the profane words used are mostly similar. The harasser is the first ranked that used profane words in the conversation compared to other roles. The results can be further explored and considered as a potential feature in a cyberbullying detection model using a machine learning approach. Results in this work will contribute to formulate the suitable representation. It is also useful in modeling a cyberbullying detection model based on the identification of profane word distribution across different cyberbullying roles in social networks for future works.

• 한국유통학회지:유통연구
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• 제1권1호
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• pp.41-63
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• 1996

In spite of economy has a critical cycle such as, production, distribution and consumption, we hardly concentrated our study to distributional system and behavior. Especially in Korea, Traditional idea had tried to ignore the people who work in this economic value at all. Manufacturers, other than retailers and wholesalers, had a belief that the manufacturing can control distributional channels forever. Unfortunately, technological and educational advances caused the quality equalization among developing and developed countries as well as among big and small manufacturers in their products. By this reason, economists are searching the economists dark continet' mentioned by Peter Drucker as a new source of wealth. According to a report by well-known economic research institute in Switzerland, Korea has classified in the lower level group in terms of international compatitive power. At the same time, business firms complain that they are suffering from lack of SOC and infrastructures. As an important mean to overcome the economic bottleneck, economists suggest in improve our distributional atmosphere. Basically, distributional study has two sub-fields as: commercial and physical distributions, Distributional system mainly concerns about to shorten the distances of time and space between production and consumption. The closer the distances, the higher efficiency can be achieved. Building distributional system will cost, but tile results will save social costs. Based on this idea, economists proposed several ways to cut the distances and to save costs, Naturally, they hope their beliefs can be adapted by business firms and governments. But frequently, their theories doesn't make any fruit. This paper has studied about the composition of joint transportational and distributional systems. And, even though there's no Marshall in tile real world at this point authors are trying to define the transportational and physical distributional costs, the most powerful factor that can impact to economic decision making.

• 한국정보과학회논문지:소프트웨어및응용
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• 제27권8호
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• pp.855-863
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• 2000

K개의 인식기로부터 관찰된 K개 결정을 결합하는 결합 방법론 중의 하나인 BKS (Behavior-Knowledge Space) 방법은 아무런 가정 없이 이들 결정을 결합하지만, 관찰된 K개 결정을 저장하고 관리하려면 이론적으로 기하학적인 저장 공간을 만들어야 한다. 즉, K개의 인식기 결정을 결합하기 위하여 (K+1)차 확률 분포를 필요로 하는데, 작은 K라 할지라도 그 확률 분포를 저장하거나 평가하는 것이 어렵다는 것은 이미 잘 알려져 있다. 그러한 문제점을 극복하기 위해서는 고차 확률 분포를 몇 개의 구성 분포로 나누고, 이들 구성 분포의 곱(product)으로 고차 확률 분포를 근사시켜야 한다. 그러한 이전 방법 중의 하나는 그 확률 분포에 조건부 독립 가정을 적용하는 것이고, 다른 방법으로는 [1]에서와 같이 그 확률 분포를 단지 트리 의존관계 또는 2차 구성 분포의 곱으로 근사하는 것이다. 본 논문에서는, 구성 분포의 곱으로 근사하는 방법에서, 2차 이상의 고차 구성 분포까지 고려하여 (K+1)차 확률 분포를 d차 ($1{\le}d{\le}K$) 의존관계에 의한 최적의 곱으로 근사하고, 베이지안 방법과 그 곱을 기반으로 다수 인식기의 결정을 결합하는 의존관계 기반의 프레임워크를 제안한다. 이 프레임워크는 표준 CENPARMI 데이타베이스로 실험되어 평가되었다.

• 유통과학연구
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• 제9권4호
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• pp.75-82
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• 2011

서비스업의 대부분에서는 감정노동이라고 하는 새로운 형태의 노동을 제공하도록 요구 받는다. 이에 따라 많은 판매사원들은 자신의 감정을 숨긴 채 고객들에게 항상 웃음으로 서비스를 제공하게 된다. 이에 본 연구에서는 백화점 판매사원의 감정노동에 관하여 실증적 연구를 진행하였다. 감정노동, 직무스트레스, 직무만족의 관계를 기초로 하여 실증분석을 시도하였다. 연구결과 첫째, 감정노동은 직무스트레스에 유의한 영향을 미치는 것으로 나타났다. 즉 감정노동이 증가함에 따라서 직무스트레스가 증가하는 것으로 나타났다. 둘째, 감정노동과 직무만족의 관계를 살펴본 결과 유의한 결과를 제시하지 못하였다. 이는 감정노동이 직무만족에 직접적인 영향보다는 간접적인 영향을 제공한다고 볼 수 있을 것이다. 셋째, 직무스트레스와 직무만족 간에 관계를 보면 역할갈등요인이 유의한 결과를 제시하고 있다. 이는 역할갈등이 증가할수록 직무만족이 떨어진다는 것을 의미하는 결과를 나타내고 있다. 이러한 결과를 통하여 감정노동이 판매사원들의 직무스트레스 및 직무만족에 직, 간접적인 영향을 미치므로 이에 대한 관리를 필요로 할 것이다. 이는 서비스를 제공하는 판매사원의 직무만족이 궁극적으로 고객 서비스 품질로 이어질 것이므로 아주 의미하는 바가 크다고 할 수 있다.

• 유통과학연구
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• 제9권3호
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• pp.83-94
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• 2011

국내에서는 일부 대기업을 제외하고는 공급사슬 관리(SCM) 체제 구축에 매우 소극적이며, 중소기업들은 SCM관리의 개념조차 인식하고 있는 경우가 대 다수이다. 이는 공급망 비효율적 관리로 인한 국내 제조업체, 협력업체, 유통업체 및 물류업체들 재고관리 비용, 수요관리 비용 등 비 효율화를 초래하고 있으며, 나아가 국내 기업의 경쟁력 저하에도 큰 영향력을 미치고 있다. 그 이유는 공급사슬 관리(SCM) 태생적인 특징인 공급사슬 관리(SCM) 전체에 대한 정보 공유 및 프로세스 혁신과, 공급사슬 관리(SCM)가 갖는 광범위함 때문이라고도 할 수 가 있다. 이 논문은 성공적인 공급사슬 관리(SCM) 추진을 위한 공급사슬 관리(SCM) 관련 이론적 논의와 구축전략과 도입 및 성공사례를 연구 및 분석을 통하여 현상황에 대한 고찰과 개선방안에 대해서 제안해보고자 한다. 성공적인 공급사슬 관리(SCM) 추진을 위한 방안을 논의하기 위해서는 먼저 공급사슬 관리(SCM)에 대한 이론적 배경에 대한 고찰이 필요하다. 따라서 II장에서는 공급사슬 관리(SCM)에 대한 기본적인 개념과 필요성에 대해서 기술하고, III장에서는 현재 추진되고 있는 공급사슬 관리(SCM)에 대한 문제점에 대해서 기술할 것이다. 마지막으로IV, V장에서는 공급사슬 관리(SCM) 구축전략과 LG전자사례 및 결론을 기술할 것이다.

• Corrosion Science and Technology
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• 제14권2호
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• pp.47-53
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• 2015

Recently, the bending process is greatly applied to fabricate the pipe line. Bending process can reduce welding joints and then decrease the number of inspection. Thus, the maintenance cost will be reduced. Induction heat bending process is composed of bending deformation by repeated local heat and cooling. By this thermal process, corrosion properties and microstructure can be affected. This work focused on the effect of induction heating bending process on the properties of ASME SA106 Gr. C low carbon steel pipes. Microstructure analysis, hardness measurements, and immersion corrosion test were performed for base metal and bended area including extrados, intrados, crown up, and down parts. Microstructure was analyzed using an optical microscope and SEM. Hardness was measured using a Rockwell B scale. Induction heat bending process has influenced upon the size and distribution of ferrite and pearlite phases which were transformed into finer structure than those of base metal. Even though the fine microstructure, every bent area showed a little lower hardness than that of base metal. It is considered that softening by the bending process may be arisen. Except of I2, intrados area, the others showed a similar corrosion rate to that of base metal. But even relatively high rate of intrados area was very low and acceptable. Therefore, it is judged that induction heat bending process didn't affect boric acid corrosion behaviour of carbon steel.

• Current Photovoltaic Research
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• 제4권1호
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• pp.21-24
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• 2016

Chalcopyrite based (CIGS) thin films have considered to be a promising candidates for industrial applications. The growth of quality CIGS thin films without secondary phases is very important for further efficiency improvements. But, the identification of complex secondary phases present in the entire film is crucial issue due to the lack of powerful characterization tools. Even though X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and normal Raman spectroscopy provide the information about the secondary phases, they provide insufficient information because of their resolution problem and complexity in analyzation. Among the above tools, a normal Raman spectroscopy is better for analysis of secondary phases. However, Raman signal provide the information in 300 nm depth of film even the thickness of film is > $1{\mu}m$. For this reason, the information from Raman spectroscopy can't represent the properties of whole film. In this regard, the authors introduce a new way for identification of secondary phases in CIGS film using depth Raman analysis. The CIGS thin films were prepared using DC-sputtering followed by selenization process in 10 min time under $1{\times}10^{-3}torr$ pressure. As-prepared films were polished using a dimple grinder which expanded the $2{\mu}m$ thick films into about 1mm that is more than enough to resolve the depth distribution. Raman analysis indicated that the CIGS film showed different secondary phases such as, $CuIn_3Se_5$, $CuInSe_2$, InSe and CuSe, presented in different depths of the film whereas XPS gave complex information about the phases. Therefore, the present work emphasized that the Raman depth profile tool is more efficient for identification of secondary phases in CIGS thin film.

• 대한지역사회영양학회지
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• 제17권3호
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• pp.302-311
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• 2012

The purpose of this study was to provide preliminary data for better safety control over children's preference foods sold in school stores. The survey was conducted from June to July 2009, to collect 749 types of children's preference foods sold in 150 middle and high school stores nation-wide excluding Jeju Island and general and nutrition information were analyzed. Out of 749 types of snack food items, 689 and 602 snacks were sold at high school and middle school stores respectively. Among children's preference foods, cookies, bread, and ice-cream were the main items. Among them, 98% of snacks were domestic products and the price range of each individual snacks were mostly between 600 and 900 won. 27.8% of children's preference foods sold were found to be in the high calorie/low nutrition food group. Even though the proportion of candy and fruit/vegetable beverages sold were not high, their proportion in high calorie/low nutrition snack group were higher than 68.1%. Among the children's preference foods sold in middle and high school stores, carbonated drinks and ramen were continuously sold in certain middle and high schools, even though sales were prohibited. This study concludes that government, corporations and retailers should work together in developing healthier children's snack distribution environment. In addition, dairy products, which take up 15% of children's preference food, should be diversified to meet their nutrient requirements.