• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.4191-4211
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• 2019

Software product lines (SPLs) are complex software systems by nature due to their common reference architecture and interdependencies. Therefore, any form of evolution can lead to a more complex situation than a single system. On the other hand, software product lines are developed keeping long-term perspectives in mind, which are expected to have a considerable lifespan and a long-term investment. SPL development organizations need to consider software evolution in a systematic way due to their complexity and size. Addressing new user requirements over time is one of the most crucial factors in the successful implementation SPL. Thus, the addition of new requirements or the rapid context change is common in SPL products. To cope with rapid change several researchers have discussed the evolution of software product lines. However, for the evolution of an SPL, the literature did not present a systematic process that would define activities in such a way that would lead to the rapid evolution of software. Our study aims to provide a requirements-driven process that speeds up the requirements engineering process using social network sites in order to achieve rapid software evolution. We used classification, topic modeling, and sentiment extraction to elicit user requirements. Lastly, we conducted a case study on the smartwatch domain to validate our proposed approach. Our results show that users' opinions can contain useful information which can be used by software SPL organizations to evolve their products. Furthermore, our investigation results demonstrate that machine learning algorithms have the capacity to identify relevant information automatically.

• 패션비즈니스
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• 제25권1호
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• pp.51-64
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• 2021

The purpose of this study was to develop smart bags that combining fashion-specific trends and smart information technologies such as light-emitting diodes(LED) and optic fibers by grafting marquage techniques that have recently become popular as part of eco-fashion. We applied e-textiles by designing leather tote bags that could show off LED luminescence. A total of two tote bags, a white-colored peacock design and a black-colored paisley design, divided the LED's light-emitting method into two types, incremental lighting and random light-emission to suit each design, and the locations of the optical fibers were also reversed depending upon the design. The production of circuits for the LEDs and optical fibers was based on the design, and a flexible conductive fabric was laser-cut instead of wire line and attached to the circuit-line location. A separate connector was underwent three-dimensional(3D)-modeling and was connected to high-luminosity LEDs and optic fiber bundles. The optical fiber logo part expressed a subtle image using a white-colored LED, which did not offset the LED's sharp luminous effects, suggesting that using LEDs with fiber optics allowed for the expression of each in harmony without being heterogeneous. Overall, the LEDs and fiber optic fabric were well-harmonized in the fashion bag using marquage techniques, and there was no sense of it being a mechanical device. Also, the circuit part was made of conductive fabric, which is an e-textile product that feels the same as a thin, flexible fabric. The study confirmed that the bag was developed as a smart wearable product that could be used in everyday life.

• 한국정밀공학회지
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• 제18권7호
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• pp.179-185
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• 2001

Porthole die extrusion is profitable to manufacture long tube with hollow section. The material through portholes is gathered within chamber and welded under high pressure. This weldability which classifies the quality of tube product is affected by several variables and die shape. But, porthole die extrusion has been executed on the experience of experts due to the complicated die assembly and complexity of metal flow. Analytic approaches that are useful in profitable die design and in the improvement of productivity are inevitably demanded. Therefore, the objective of this study is respectively to analyze the behavior of metal flow and to determine welding pressure of hot extrusion product according to the various billet temperature, bearing length and tube thickness by FE analysis and its results are compared with tube expanding tests.

• 산업경영시스템학회지
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• 제22권53호
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• pp.45-54
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• 1999

Manufacturing today is becoming increasingly competitive. If a company is to exist and successfully compete, it must pay very careful attention to production management, total quality assurance and total proactive maintenance issues. Overall machine performance, repair efficiency, system level utilization, productivity and quality of output need to be optimized as possible. To accomplish that objective, the behavior of manufacturing equipment and systems need to be monitored and measured continuously if it is possible. Then early warning of possible failure should be generated and proacted on that type of the situation to improve overall operation performance of manufacturing environment. In this paper, Proactive maintenance framework using performance-based reliability structure as enabler technology is proposed. Its paradigm enables one to maximize system through-put and product quality as well as resources in the performance domain. In the case of inadequate knowledge of the failure mechanics, this empirical modeling concept along with performance degradation knowledge can serve as an important product and process improvement tool. The real-time framework extension to proposed framework uses on-line performance information and is capable of projecting the remaining useful period.

• 한국표면공학회지
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• 제53권4호
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• pp.138-143
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• 2020

In this study, we produced a coil of micro-pattern that can be used for electromagnetic wave absorber, heating material, wireless charging, sensor, antenna, etc. by using electrochemical additive manufacturing method. Currently, it contains research contents for manufacturing a micro pattern coil having practicality through control of process control variables such as applied voltage, distance between electrode, and nozzle injection. Circulation of the electrolyte through the nozzle injection control can significantly contribute to improving the surface characteristics of the coil because of minimizing voltage fluctuations that may occur during the additive manufacturing process. In addition, by applying the pulse method in the application of voltage, the lamination characteristics of the plated body were improved, which showed that the formation of a fine line width plays an important role in the production of a micro pattern coil. By applying the pulse signal to the voltage application, the additive manufacturing characteristics of the produced product were improved, and it was shown that the formation of a fine line width plays an important role in the production of a micro pattern coil.

• 소성∙가공
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• 제32권3호
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• pp.129-135
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• 2023

The use of engineering plastic products in internal combustion engine and electric cars to improve stiffness and reduce weight is increasing significantly. Among various lightweight materials, engineering plastics have significant advantages such as cost reduction, improved productivity, and weight reduction. In particular, engineering plastics containing glass fibers are used to enhance stiffness. However, the stiffness of glass fibers can increase or decrease depending on their orientation. Before developing plastic products, optimal designs are determined through injection molding and structural analysis to enhance product reliability. However, reliable analysis of products with variable stiffnesses caused by anisotropy cannot be achieved via the conventional isotropic structural analysis, which does not consider anisotropy. Therefore, based on the previously reported study "the Effect of Impacted Fracture in Glass Fiber Orientation with Injection Molding & Structural Coupled Analysis," this study aims to investigate the structural analysis and degradation mechanisms of various polymers. In particular, this study elucidates the actual mechanism of plastic fracture by analyzing various fracture conditions and their corresponding simulations. Furthermore, the objective of this study is to apply the injection molding and structural coupled analysis mechanism to develop engineering plastic products containing glass fibers. In addition, the study aims to apply and improve the plastic fracture mechanism in actual products by exploring anisotropy and stiffness reduction owing to the unfilled polymer weld line.

• 한국산업정보학회논문지
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• 제20권3호
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• pp.51-60
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• 2015

추적성은 이해당사자들이 변경으로 인한 산출물들 간의 영향을 분석하는데 필요한 정보를 제공하는 것을 주요 목적으로 한다. 단일 제품 개발과 달리 제품군(群)을 대상으로 하는 소프트웨어 프로덕트라인은 도메인 공학과 어플리케이션 공학의 두 개발 라이프사이클이 있으면서, 가변성과 두 라이프사이클 간의 추적성을 유지하고 관리해야 하기 때문에 그 복잡도가 매우 높다. 이에 개발 산출물과 별도로 가변성을 관리하는 직교적 가변성 모델을 중심으로 하는 가변성 추적성 유지 방법이 개념적으로 제안된 바 있다. 그렇지만, 이 방법이 소프트웨어 제품라인에서 필요로 하는 추적성을 모두 설정할 수 있는지에 대해서는 확인되지 않았다. 본 논문에서는 직교적 가변성 모델을 중심으로 하는 추적성 유지, 관리 방법이 필요한 추적성을 모두 지원하는지 예제를 통하여 검증하였다. 그 결과 OVM 중심 가변성 추적 방법은 변경으로 인해 영향을 받을 수 있는 산출물들의 범위를 한정하는 데는 문제가 없었다. 그렇지만, 변경으로 인해 실제 영향을 받는 구체적이고 정확한 산출물들을 추적하지는 못했다.

• 한국정보통신학회논문지
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• 제20권7호
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• pp.1237-1242
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• 2016

본 논문은 병렬 결합선로(coupled-line)와 부채꼴(radial) 개방형 스터브(stub)를 이용한 고조파가 억압된 저역통과 여파기에 대해 제안을 한다. 본 제안한 저역통과 여파기의 특징은 병렬 결합선로의 구조 때문에 고조파가 광대역으로 억압되었다는 결과를 얻을 수 있었다. 저역통과 여파기의 개방형 스터브는 부채꼴로 구성되어 있으며 이는 여파기의 크기를 조절 할 수 있다. 제안한 저역통과 여파기의 크기는 $6.98{\times}7.60mm2$이며 차단 주파수는 2.45 GHz 이다. 분포정수소자(distributed element)로 구성되어 있어 단가면에서 경제적이고 제작이 쉬우며 대량 생산이 가능한 이점이 있다. 또한 광대역 고조파 억압에 대한 대역폭은 128 %이며 여파기의 삽입 및 반사 손실은 각각 1.07 dB 및 19.5 dB를 얻었다.

• 한국산업융합학회 논문집
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• 제23권3호
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• pp.427-431
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• 2020

In this Study, as the structure of IT module for smart phone display becomes thin to catch up with slim product trend, the reliability of display module is on the rise as a issue for product design. Especially, almost part of cellular phone should undergo thermal dissipation test. thus many manufacturers have considered design guide line using CAE and simulation for more effective usage of limited resources on the market. This test simulates the case when cellular phone slips through user's fingers while he is talking on the phone. This paper studies a thermal simulation of display module in smart phone. This design for reliability improvements are suggested on the basis of the results of FVM Analysis and display of IT module and smart phone design.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.365-368
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• 2006

The implementation of a screening procedure for removing non-conforming products has become a common practice especially in high-tech manufacturing industries. Screening procedures involve a measurement on the quality characteristic of interest since decisions regarding the conformance to specifications are usually made on the basis of the realization of measurement. A significant variability in measurement procedures may result in the misclassification of an outgoing product (that is, falsely accepting defectives or falsely rejecting conforming items), which may lead to wrong interpretation on product quality, It may thus be necessary to consider the impacts of misclassification errors due to measurement variability when designing screening procedures. Along this line, this article investigates the design of screening procedures based on the assessment of misclassification errors. The main objective is to determine the screening limits on measured values so that two types of misclassification errors may properly be compromised.