• Journal of the Optical Society of Korea
• /
• v.17 no.6
• /
• pp.506-512
• /
• 2013

Recently, the color separation issue of wide-spreading white LEDs has attracted attention due to their wide applicability as light sources in direct-lit LCD backlights. These wide-spreading LED packages usually consist of LED chips, a color-conversion phosphor layer, and a light-shaping lens. The technical aspect of this color issue was related to a method for balancing the yellow spectral component emitting from phosphors with respect to the blue one from the LED chip as a function of viewing angle. In this study, we suggested an approach for carrying out quantitative analysis for the color separation problem occurring in wide-spreading LED packages by optical simulation. In addition, the effect of an internal scattering layer on the color uniformity was investigated, which may be considered as a potential solution for this problem.

• Journal of Aerospace System Engineering
• /
• v.15 no.4
• /
• pp.7-10
• /
• 2021

Including 425 Program, which is Korean military surveillance and reconnaissance satellite, there were mostly civil-driven space programs in Korea. However, there are increasing numbers of military demand-driven space program in nowadays. Furthermore, it is positive effects on launch vehicle development in Korea that the termination of Korea-U.S. missile guideline. In this paper, it emphasizes the needs of system engineering(SE) management method which meets both defense system's characteristics and space's characteristics. These characteristics are such as non-fixable after the launch, the security issue in defense system. And it also introduces SE tool, methodology and its philosophy. There are several functions that data management, issue management, risk management, and technical requirement management. Also describing its implications and direction of improvement.

• International Journal of Internet, Broadcasting and Communication
• /
• v.9 no.3
• /
• pp.59-69
• /
• 2017

The best 'hub' to communicate with the citizen is using social media to marketing the business. However, there has several issued and the most common issue that face in critical is a capital issue. This issue is always highlight because most of automatic sentiment detection tool for Facebook or any other social media price is expensive and they lack of technical skills in order to control the tool. Therefore, in directly they have some obstacle to get faster product's feedback from customers. Thus, the personal online retailing need to struggle to stay in market because they need to compete with successful online company such as G-market. Sentiment analysis also known as opinion mining. Aim of this research is develop the tool that allow user to automatic detect the sentiment comment on social media account. RAD model methodology is chosen since its have several phases could produce more activities and output. Soppy tool will be develop using Microsoft Visual. In order to generate an accurate sentiment detection, the functionality testing will be use to find the effectiveness of this Soppy tool. This proposed automated Soppy Tool would be able to provide a platform to measure the impact of the customer sentiment over the postings on their social media site. The results and findings from the impact measurement could then be use as a recommendation in the developing or reviewing to enhance the capability and the profit to their personal online retailing company.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.331-337
• /
• 2009

This paper summarizes some of approaches that could be taken for data exchange in a non-interoperable work environment and reports lessons learned from the Dongdaemun Design Plaza and Park project. Today's widespread application of building information modeling (BIM) to the construction and architectural design industries requires a change in the cooperation between business organizations and their methods of communication. In particular, the interoperability of information between interdisciplinary organizations, which use specific programs for different purposes, has become a critical issue. More than just a technical problem, it is also highly related to an organization's collaboration culture and the particulars of a specific project. This paper describes the interoperability issue that occurred during the construction documentation phase of the irregularly shaped building project, Dongdaemun Design Plaza and Park, designed by Zaha Hadid Architects and Samoo Architects and Engineers, from the perspective of the technological problem and the collaborative organizations' communications. Although the perfect compatibility of information is not possible, this paper deals with a practical approach to the interoperability issue by examining the way the end-users of computer-aided design (CAD) resolved the interoperability problems in practice.

• Journal of the Korea Institute of Building Construction
• /
• v.19 no.3
• /
• pp.255-261
• /
• 2019

Poor working conditions in the construction industry have made young people reluctant to enter it, resulting in supply/demand unbalance of construction skilled worker. Currently, most construction workers in Korea acquire skills through apprenticeships. Against this background, this study aimed to identify problems in apprenticeship-based methods of technical education, and to suggest measures that could improve these methods. As a measure to improve current apprenticeship-based methods of technical education, technical education needs to be regularly provided on construction sites, and each construction company needs to issue a certificate to workers confirming their completion of technical education. It is also necessary to establish a system in which this certificate is recognized as education experience. In addition, it is recommended to form partnerships with construction technology education institutes supported by the government in order to provide construction workers with opportunities to receive new technologies and construction methods free of charge, and it is urgently necessary to establish and implement a policy to adequately support their cost of living during this period.

• Journal of the Korean Society of Radiology
• /
• v.81 no.3
• /
• pp.549-561
• /
• 2020

Since the endosaccular coil embolization technique was introduced as an alternative for treating selected patients with aneurysms, it has become a mainstay of treatment for cerebral aneurysms. In lesions with a neck larger than the aneurysmal body, an irregular shape, or arterial branches incorporated within the sac, endovascular treatment using detachable coils are traditionally contraindicated because of technical difficulties. Coil embolization has evolved as a result of both the development of related devices and the introduction of technical improvements using various devices. Use of various technical and device options can make endovascular treatment of cerebral aneurysms safer and can widen the treatment indications. Various technical options, including the technical modification of device-assisted techniques, will be presented, and the related practical points will be discussed in this issue.

• KIEAE Journal
• /
• v.8 no.5
• /
• pp.23-34
• /
• 2008

This paper reviews the relationships between diverse ecological design strategies and competing conceptions of ecological approach in place making. It focuses conceptual trends of what we categorize a building "green" and outlines a social constructive perspective on the development of sustainable architecture. This study classifies seven logics of ecological design-eco-technical, eco-aesthetical, eco-social, eco-medical, eco-renewable, eco-cultural, eco-central - which have their roots in competing philosophies of environmentalism. In my analysis of the logics concerning sustainable architecture, the adapted and incorporated technology from high-tech to low-tech levels is a key issue. These points lead us to propose a way that each logic configures the technological approaches and alternative visions of sustainable places. This paper discusses the implications of the competent nature of plural ecological design perspectives for architectural education, practice, and researches.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.460-462
• /
• 2004

The control of the data retention time is a main issue for realizing future high density dynamic random access memory. There are several leakage current mechanisms in which the stored data disappears. The mechanisms of data disappear is as follow, 1 )Junction leakage current between the junction, 2) Junction leakage current from the capacitor node contact, 3)Sub-threshold leakage current if the transfer transistor is affected by gate etch damage etc. In this paper we showed the plasma edge damage effect to find out data retention time effectiveness. First we measured the transistor characteristics of forward and reverse bias. And junction leakage characteristics are measured with/without plasma damage by HP4145. Finally, we showed the comparison TRET with etch damage, damage_cure_RTP and hydrogen_treatment. As a result, hydrogen_treatment is superior than any other method in a curing plasma etch damage side.

• Journal of the Korean Society of Safety
• /
• v.30 no.1
• /
• pp.1-7
• /
• 2015

This study first addresses the ineffectiveness of indirect regulation on industrial machines. Analysis of causes of industrial accidents associated with industrial machines further reveals the fact that technical causes need to be resolved at the manufacturing stage to reduce the frequency and strength of industrial accidents. Balanced safety certification on manufacturers and safety inspection on users of industrial machines are then suggested to effectively resolve such technical causes. The effectiveness of such safety certification and safety inspection can be justified by cost-benefit analysis. Particularly, balance in expected benefits of safety certification and safety inspection is a key issue for validity of such analysis. The accumulated benefit-costs for press brake and portable sawing machine confirm the effectiveness of such safety system.

• Aerospace Engineering and Technology
• /
• v.6 no.1
• /
• pp.6-13
• /
• 2007

PAV(Personal Air Vehicle) can be an alternative of the saturated ground transportation in future and can be available in any time and anywhere. This paper describes some overview on high speed rotorcraft concepts for the PAV applications. First the requirement of PAV is surveyed. Then the existing concepts of high speed rotorcrafts are reviewed. Several on-going projects are summarized. Finally! technical issues of high speed rotorcraft to apply to PAV platform are explored.