• Journal of Korean Society of Steel Construction
• /
• v.14 no.1
• /
• pp.13-21
• /
• 2002

In this paper, 3-D frame design using refined plastic-hinge analysis accounting for local buckling is developed. This analysis accounts for material and geometric nonlinearities of the structural system and its component members. Moreover, the problem associated with conventional refined plastic-hinge analyses, which do not consider the degradation of the flexural strength caused by local buckling, is overcome. Efficient ways of assessing steel frame behavior including gradual yielding associated with residual stresses and flexure, second-order effect, and geometric imperfections are presented. In this study, a model consisting of the width-thickness ratio is used to account for local buckling. The proposed analysis is verified by the comparison of the LRFD results. A case study shows that local buckling is a very crucial element to be considered in second-order plastic-hinge analysis. The proposed analysis is shown to be an efficient, reliable tool ready to be implemented into design practice.

• Journal of Practical Engineering Education
• /
• v.12 no.1
• /
• pp.11-21
• /
• 2020

This study is a phenomenological study that aimed to understand the meaning of nursing students' experience of class using flipped learning method. The participants are 8 senior nursing students. The data collected by individual in-depth interviews and analyzed by Colaizzi's method. As a result of this study, 35 key themes and 11 clusters of themes were derived. The 11 thematic categories are classified in pre-education, in-classroom, and post-education. At the pre-education, the theme clusters are 'lack of information', 'psychological burden', 'different teaching methods', 'improvement of self-directed learning ability', and 'different learner's achievement'. At the in-class, the theme clusters are 'efficient teaching direction' and 'confidence improvement'. At the post-education stage, the theme clusters are 'positive influence on class', 'strengthening self-pay', 'not preferred', and 'lecture preference'. Therefore, a more diversified and in-depth repetitive study is suggested in order to apply the flipped learning method to the nursing major.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.30-30
• /
• 2018

스마트 도금공장을 구축하기 위해서는 도금액 내부의 화학 물질 농도 변화를 측정할 수 있는 화학 센서 기술이 필수적으로 요구된다. 와트욕은 대표적인 고속 니켈 도금액 중 하나로 기본적으로 황산니켈, 염화니켈, 보릭산의 염과 함께 케리어(type-1 광택제), 광택제(type 2-광택제), 응력 제어제 등의 유기 첨가제로 구성되어 있다. 이러한 유기 첨가제는 전차된 니켈층의 두께 균일도, 조도, 미세 구조, 내부 응력 등 다양한 특성을 제어하며, 정밀한 농도 관리가 필수적으로 요구되나, 분석 기술의 부재로 인하여 지금까지도 대부분의 액관리는 할셀법이나 작업자의 경험에 의존하고 있다. Cyclic voltammetry stripping(CVS) 방법은 전기화학 분석 과정에서 나타나는 첨가제의 가속, 감속 특성 등과 여기에 수반되는 stripping peak의 변화를 이용하여 개별 첨가제의 농도를 측정하는 방법이며, 지금까지 인쇄회로기판의 비아필 공정, 전해 동박 제조, 반도체 배선 등 구리도금 산업 전반에 걸쳐 첨가제 관리에 효과적으로 적용되고 있다. 그러나 수소 발생으로 인한 stripping 효율 문제로 인하여 니켈, 주석, 아연 등 표준 환원 전위가 높은 금속 도금액 내부 첨가제 농도 측정은 아직 어려운 상황이다. 본 연구에서는 이 문제를 극복하기 위해 염소를 과량 첨가한 구리 도금액을 CVS 분석의 base 용액으로 이용하여 니켈 도금액 내부 여러 광택제 (polyetylene glycol(PEG) 계열, thiourea 계열, 2-butyne-1,4-diol 등) 농도를 측정하는 법을 제시하였다. 제시된 방법은 CVS 분석 과정에서 구리-염소 사이의 상호 작용으로 인해 생성되는 3가지 stripping peak의 상대적인 크기 변화가 첨가제 농도에 따라 영향을 받는다는 사실에 기반하였다. 본 연구에서는 여기에 관한 원인에 대해 고찰하였으며, 제시된 방법을 통해 광택제 계열 첨가제 농도 측정을 선택적으로 할 수 있다는 것을 증명하였다.

• Journal of Information Management
• /
• v.40 no.2
• /
• pp.71-94
• /
• 2009

Indexing images using traditional indexing methods like taxonomy is not always efficient because of its visual content. This study examined how to apply folksonomies to image retrieval. To do this, first, we developed a category model for image tags found in Flickr. The model includes five categories and seventeen subcategories. Second, in order to evaluate the usefulness of the model to represent the various image tags as well as to investigate the end-user tagging behavior, three researchers classified the sampled image tags(141 most popular tags, 105 tags on three individual tag clouds and 3,848 image tags assigned on 156 images) according to the model. Finally, based on the research results, we proposed three methods for efficient image retrieval: extending folksonomies by combining them with ontologies; improving image retrieval efficiency using visual content and folksonomies; and updating taxonomy using folksonomies.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.89-94
• /
• 2004

A steel plated is typically composed of plate panels. The overall failure of the structure is certainly affected and can be governed by the bulking and plastic collapse of these individual members. In the ultimate limit state design, therefore, a primary task is to accurately calculate the buckling and plastic collapse strength of such structural members. Structural elements making up steel palated structures do not work separately, resulting in high degree of redundancy and complexity in contrast to those of steel framed structures. To enable the behavior of such structures to be analyzed, simplifications or idealizations must essentially be made considering the accuracy need and degree of complexity of the analysis to be used. Generally the more complex the analysis the greater is the accuracy that may be obtained. The aim of this study is the investigation of the effect of the tripping behaviour including section characteristic for a plate under uniaxial compression. For this purpose of study, in used elasto-plasticity deformation FEA method are used for this study.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.36S no.10
• /
• pp.113-122
• /
• 1999

When we want to retrieve the most similar image from the image database, the color histogram intersection, shape feature and texture feature comparing method are used as a metric to measure the similarity. In order to increase the accuracy of retrievals, we need to integrate two different features. In this paper, the histogram intersection and shape based block histogram intersection method are used. This method results in a high efficient algorithm that meets a similar accuracy and a relatively fast retrieval speed compared to the method of integration of two different features. The Proposed algorithm is tested on retrievals of image database consisting of various 600 images and we implemented that the proposed algorithm gives fast, high efficiency and reliability compared to others.

• The Korean Journal of Air & Space Law and Policy
• /
• v.26 no.2
• /
• pp.69-100
• /
• 2011

The penalty clauses of 'Aviation Act' and 'Aviation Safety and Security Act' going into effect now were legislated because the aviation safety is being more influenced by the aviation safety system compared to the ground or maritime transportation and it is possible the aircraft can harm to people and wealth located in the ground as well as threaten the safety of the passengers and crew on board when it is the target of crimes. However, analyzing the current acts, applicable objects and behavioral requirements of some provisions are too general, and they are providing severely high penalties in many clauses without separating applicable objects and behavioral requirements. In addition, there are some critical legislative defects and there is a problem in terms of law-applicable area in the legal system. It is inferred that these legislative problems of the criminal special-law related to the aviation were caused by following reasons; first, aviation security experts or policy-makers than criminal law experts attended more actively in the enactment process, second, the communication among specialist groups were not accomplished well enough.

• Journal of Convergence for Information Technology
• /
• v.9 no.7
• /
• pp.14-24
• /
• 2019

It is necessary to look into multiple subjects, such as effectiveness, laws and polices of blockchain in order to easily accept blockchain technology in small and mid-sized enterprises(SME). This study analyzes the positive effects of applying the block chain to SMEs, examines the laws and policies required to apply them, and identifies the tasks. As a result, we confirmed that it can create positive effects such as optimizing supply chain management, simplifying import and export process documents, improving product quality, facilitating flow of funds, and improving transaction reliability. Also, we confirmed that it is necessary to improve the basic law of electronic transaction, electronic commerce law, electronic financial transaction law, personal information protection legislation, and needs policy supplement for platform development, education system for SMEs, transaction standardization guidelines, tax reduction policy, and block chain research and development. More extensive practical research and specific individual legal studies are needed in the future.

• Journal of the Korea Society for Simulation
• /
• v.28 no.3
• /
• pp.65-74
• /
• 2019

For many years, it has been widely studied on fork-join production systems but there is not much literature focusing on the finite buffer(s) of either individuals or shared, and generally distributed processing times. Usually, it is difficult to handle finite buffer(s) through a standard queueing theoretical approach. In this study, by using the max-plus algebraic approach we studied buffer-shared fork-join production systems with general processing times. However, because it cannot provide proper computational ways for performance measures, we developed simulation models using @RISK software and the expressions derived from max-plus algebra. From the simulation experiments, we compared some properties on waiting time with respect to a buffer capacity under two blocking policies: BBS (Blocking Before Service) and BAS (Blocking After Service).

• Journal of the Korean Society for Library and Information Science
• /
• v.55 no.2
• /
• pp.25-50
• /
• 2021

General-purpose classification scheme encompasses all subject areas, While the whole classification scheme is constructed by library studies experts, structure and preparation of each specific subject area's classification should be referenced to that specific subject. In order for the whole system to be practical and useful classification scheme, not just a simple collection of each subject area's scheme, it is necessary to set the rule for properly distributing the amount of classification items, and the collections assigned to these items. The rule to set the distribution of items based on the amount of document collections is called 'literary warrant'. This study examines actual status of assignment of each classification items to information resources, as a result of application of Korean Decimal Classification, and then suggests a way to improve these practices.