• Title/Summary/Keyword: challenging problems

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Methods to Apply GoF Design Patterns in Service-Oriented Computing (서비스 지향 컴퓨팅을 위한 GoF 디자인 패턴 적용 기법)

  • Kim, Moon-Kwon;La, Hyun-Jung;Kim, Soo-Dong
    • The KIPS Transactions:PartD
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    • v.19D no.2
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    • pp.187-202
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    • 2012
  • As a representative reuse paradigm, the theme of service-oriented Paradigm (SOC) is largely centered on publishing and subscribing reusable services. Here, SOC is the term including service oriented architecture and cloud computing. Service providers can produce high profits with reusable services, and service consumers can develop their applications with less time and effort by reusing the services. Design Patterns (DP) is a set of reusable methods to resolve commonly occurring design problems and to provide design structures to deal with the problems by following open/close princples. However, since DPs are mainly proposed for building object-oriented systems and there are distinguishable differences between object-oriented paradigm and SOC, it is challenging to apply the DPs to SOC design problems. Hence, DPs need to be customized by considering the two aspects; for service providers to design services which are highly reusable and reflect their unique characteristics and for service consumers to develop their target applications by reusing and customizing services as soon as possible. Therefore, we propose a set of DPs that are customized to SOC. With the proposed DPs, we believe that service provider can effectively develop highly reusable services, and service consumers can efficiently adapt services for their applications.

A Study on Development Direction of Public Interest Contents through Gamification Case Analyses in Domestic and Foreign Environmental Fields (국내·외 환경분야 게이미피케이션 사례분석을 통한 공익 콘텐츠 개발 방향 연구)

  • Kim, Joo Woo;Jeong, Eui Jun
    • Journal of Korea Game Society
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    • v.14 no.5
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    • pp.161-182
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    • 2014
  • As environmental problems such as global warming, and ecocide have a great influence on society, the attention to environmental pollution is being expanded. To solve the environmental problems, the awareness and practice of members of society in question is required. However, it has been found that few people are participating in practising environmental protection in real life. Our main goals are to show that Gamification has great potential in delivering messages for public interest and to suggest guidelines for researchers and public contents developers who engage in designing in relation to Gamification. Based on the domestic and foreign theoretical investigations, we found that Gamification mechanism made based on psychological mechanism of users aims at public interests' value by maximizing motivations of users and spreading social relationships among people. As shown in the case study, if contents are developed by reflecting the elements which stimulate challenging of users, the elements which can express their opinions, and the elements of altruism which form the sympathy in the development of public interest contents in the future, practical participation of people to solve social problems can be expected.

Waveguide Spatial Interference Filtering in Adaptive Matched Field Processing (적응 정합장처리에서 도파관 공간간섭 필터링)

  • 김재수;김성일;신기철;김영규;박정수
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.4
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    • pp.288-295
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    • 2004
  • Detection and localization of a slow and quiet target in shallow water environments is a challenging problem for which it is well known that snapshot is deficient because of a fast and strong interferer. This paper presents waveguide interference filtering technique that mitigate strong interferer problems in adaptive matched field processing. MCM (multiple constraint method) based on NDC (null direction constraint) has been proposed for new spatial interferer filter. MCM-NDC using replica force a interferer component to be filtered through CSDM (cross-spectral density matrix). This filtering have an effect on sidelobe reduction and restoring of signal gain of a quiet target. This technique was applied to a simulation on Pekeris waveguide and vertical array data from MAPLE03 (matched acoustic properties and localization experiment) in the East Sea and was shown to improve SBNR (signal-to-background-and-noise ratio) over the standard MVDR (minimum-variance distortionless response) and NSP (null space projection) technique.

Discovery and Execution Techniques of Semantic Web Services for Dynamic Web Services Composition (동적 웹 서비스 조합을 위한 시멘틱 웹 서비스 발견 및 실행 기법)

  • Lee Yong-ju
    • The KIPS Transactions:PartD
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    • v.12D no.6 s.102
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    • pp.889-898
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    • 2005
  • Recently, one of the most challenging problems is to compose web services dynamically, that is, on demand. A number of researchers have been considerably interested in the dynamic web services composition. However, while most of them focused on the semi-automatic web services composition with a human controller, very little attention was devoted to the full automation of this process. This paper primarily focuses on the automatic web services composition techniques. The main idea is to implement an automatic web services composition system using web ontologies to realize the semantic web and workflow technologies to play a major role in E-businesses. In this paper, we propose a matching algorithm for web service discovery and present an approach based on the use of ontologies to facilitate the interoperability of web services. Finally, we describe a workflow execution plan to support the automatic web services composition, and an experimental study that shows the high performance of our system.

An Improved Genetic Approach to Optimal Supplier Selection and Order Allocation with Customer Flexibility for Multi-Product Manufacturing

  • Mak, Kai-Ling;Cui, Lixin;Su, Wei
    • Industrial Engineering and Management Systems
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    • v.11 no.2
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    • pp.155-164
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    • 2012
  • As the global market becomes more competitive, manufacturing industries face relentless pressure caused by a growing tendency of greater varieties of products, shorter manufacturing cycles and more sophisticated customer requirements. Efficient and effective supplier selection and order allocation decisions are, therefore, important decisions for a manufacturer to ensure stable material flows in a highly competitive supply chain, in particular, when customers are willing to accept products with less desirable product attributes (e.g., color, delivery date) for economic reasons. This paper attempts to solve optimally the challenging problem of supplier selection and order allocation, taking into consideration the customer flexibility for a manufacturer producing multi-products to satisfy the customers' demands in a multi period planning horizon. A new mixed integer programming model is developed to describe the behavior of the supply chain. The objective is to maximize the manufacturer's total profit subject to various operating constraints of the supply chain. Due to the complexity and non-deterministic polynomial-time (NP)-hard nature of the problem, an improved genetic approach is proposed to solve the problem optimally. This approach differs from a canonical genetic algorithm in three aspects: a new selection method to reduce the chance of premature convergence and two problem-specific repair heuristics to guarantee feasibility of the solutions. The results of applying the proposed approach to solve a set of randomly generated test problems clearly demonstrate its excellent performance. When compared with applying the canonical genetic algorithm to locate optimal solutions, the average improvement in the solution quality amounts to as high as ten percent.

Multiple Vehicle Recognition based on Radar and Vision Sensor Fusion for Lane Change Assistance (차선 변경 지원을 위한 레이더 및 비전센서 융합기반 다중 차량 인식)

  • Kim, Heong-Tae;Song, Bongsob;Lee, Hoon;Jang, Hyungsun
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.2
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    • pp.121-129
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    • 2015
  • This paper presents a multiple vehicle recognition algorithm based on radar and vision sensor fusion for lane change assistance. To determine whether the lane change is possible, it is necessary to recognize not only a primary vehicle which is located in-lane, but also other adjacent vehicles in the left and/or right lanes. With the given sensor configuration, two challenging problems are considered. One is that the guardrail detected by the front radar might be recognized as a left or right vehicle due to its genetic characteristics. This problem can be solved by a guardrail recognition algorithm based on motion and shape attributes. The other problem is that the recognition of rear vehicles in the left or right lanes might be wrong, especially on curved roads due to the low accuracy of the lateral position measured by rear radars, as well as due to a lack of knowledge of road curvature in the backward direction. In order to solve this problem, it is proposed that the road curvature measured by the front vision sensor is used to derive the road curvature toward the rear direction. Finally, the proposed algorithm for multiple vehicle recognition is validated via field test data on real roads.

Verification of Safety in a RFID Security Authentication Protocol Using Session and Public Keys (세션키 및 공개키를 이용한 RFID 보안 인증 프로토콜의 안전성 검증)

  • Bae, Woo Sik;Lee, Jong Yun
    • Journal of Digital Convergence
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    • v.10 no.10
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    • pp.325-332
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    • 2012
  • Due to its communication vulnerability resulting in a range of problems, e.g. eavesdropping, information exposure, traffic analysis and spoofing, RFID system becomes the target of attackers. Accordingly, many investigators have proposed various protocols to the extent of theorem proving or verification as the implementation is challenging. This paper thus proposes a safe RFID security protocol using public keys, session keys, hashes, XORs, and random numbers. Timestamps and hashes are applied to the most vulnerable section between readers and tags to detect attacks in attack signals with time difference. Also, to prevent tag information from being exposed in the last session, hash operation is adopted before communication. Finally, in this paper, we designed a RFID security protocol using public and session keys applicable to real systems and verified the security of the proposed protocol with a differentiated formal verification technique.

Cryptic variation, molecular data, and the challenge of conserving plant diversity in oceanic archipelagos: the critical role of plant systematics

  • Crawford, Daniel J.;Stuessy, Tod F.
    • Korean Journal of Plant Taxonomy
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    • v.46 no.2
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    • pp.129-148
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    • 2016
  • Plant species on oceanic islands comprise nearly 25% of described vascular plants on only 5% of the Earth's land surface yet are among the most rare and endangered plants. Conservation of plant biodiversity on islands poses particular challenges because many species occur in a few and/or small populations, and their habitats on islands are often disturbed by the activity of humans or by natural processes such as landslides and volcanoes. In addition to described species, evidence is accumulating that there are likely significant numbers of "cryptic" species in oceanic archipelagos. Plant systematists, in collaboration with others in the botanical disciplines, are critical to the discovery of the subtle diversity in oceanic island floras. Molecular data will play an ever increasing role in revealing variation in island lineages. However, the input from plant systematists and other organismal biologists will continue to be important in calling attention to morphological and ecological variation in natural populations and in the discovery of "new" populations that can inform sampling for molecular analyses. Conversely, organismal biologists can provide basic information necessary for understanding the biology of the molecular variants, including diagnostic morphological characters, reproductive biology, habitat, etc. Such basic information is important when describing new species and arguing for their protection. Hybridization presents one of the most challenging problems in the conservation of insular plant diversity, with the process having the potential to decrease diversity in several ways including the merging of species into hybrid swarms or conversely hybridization may generate stable novel recombinants that merit recognition as new species. These processes are often operative in recent radiations in which intrinsic barriers to gene flow have not evolved. The knowledge and continued monitoring of plant populations in the dynamic landscapes on oceanic islands are critical to the preservation of their plant diversity.

Hole-Filling Method for Depth-Image-Based Rendering for which Modified-Patch Matching is Used (개선된 패치 매칭을 이용한 깊이 영상 기반 렌더링의 홀 채움 방법)

  • Cho, Jea-Hyung;Song, Wonseok;Choi, Hyuk
    • Journal of KIISE
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    • v.44 no.2
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    • pp.186-194
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    • 2017
  • Depth-image-based rendering is a technique that can be applied in a variety of 3D-display systems. It generates the images that have been captured from virtual viewpoints by using a depth map. However, disoccluded hole-filling problems remain a challenging issue, as a newly exposed area appears in the virtual view. Image inpainting is a popular approach for the filling of the hole region. This paper presents a robust hole-filling method that reduces the error and generates a high quality-virtual view. First, the adaptive-patch size is decided using the color and depth information. Also, a partial filling method for which the patch similarity is used is proposed. These efforts reduce the error occurrence and the propagation. The experiment results show that the proposed method synthesizes the virtual view with a higher visual comfort compared with the existing methods.

Simple Correction of Alar Retraction by Conchal Cartilage Extension Grafts

  • Jang, Yong Jun;Kim, Sung Min;Lew, Dae Hyun;Song, Seung Yong
    • Archives of Plastic Surgery
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    • v.43 no.6
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    • pp.564-569
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    • 2016
  • Background Alar retraction is a challenging condition in rhinoplasty marked by exaggerated nostril exposure and awkwardness. Although various methods for correcting alar retraction have been introduced, none is without drawbacks. Herein, we report a simple procedure that is both effective and safe for correcting alar retraction using only conchal cartilage grafting. Methods Between August 2007 and August 2009, 18 patients underwent conchal cartilage extension grafting to correct alar retraction. Conchal cartilage extension grafts were fixed to the caudal margins of the lateral crura and covered with vestibular skin advancement flaps. Preoperative and postoperative photographs were reviewed and analyzed. Patient satisfaction was surveyed and categorized into 4 groups (very satisfied, satisfied, moderate, or unsatisfied). Results According to the survey, 8 patients were very satisfied, 9 were satisfied, and 1 considered the outcome moderate, resulting in satisfaction for most patients. The average distance from the alar rim to the long axis of the nostril was reduced by 1.4 mm (3.6 to 2.2 mm). There were no complications, except in 2 cases with palpable cartilage step-off that resolved without any aesthetic problems. Conclusions Conchal cartilage alar extension graft is a simple, effective method of correcting alar retraction that can be combined with aesthetic rhinoplasty conveniently, utilizing conchal cartilage, which is the most similar cartilage to alar cartilage, and requiring a lesser volume of cartilage harvest compared to previously devised methods. However, the current procedure lacks efficacy for severe alar retraction and a longer follow-up period may be required to substantiate the enduring efficacy of the current procedure.