• 한국멀티미디어학회논문지
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• 제18권9호
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• pp.1105-1117
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• 2015

During the last decade, the business infrastructure has become digital with increased interconnections among products, processes, and services. Across many firms spanning different industries and sectors, digital technologies are fundanmentally transforming business stratiges, business processes, firm capabilities, productes and services, and key interfirm relationships in extended business networks. With the emergence of smartphones, the paradigm of the ICT industry is rapidly changing as the line between global and local markets are being blurred. In the changing global environment, although some game companies are accelerating the improvement of their global competitiveness and cases of successes of venture enterprises by developing biosimilar technology are being discovered, majority of ICT companies are focusing on limited marketing activities to get subcontracts or projects from large companies. Thus the aim of this study is to find out how digital ecosystems evolve and how business models and strategies have changed of individual companies according to the evolution of the digital ecosystems.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.870-875
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• 2004

Beam stiffeners have frequently been used for raising natural frequencies of base structures. In stiffener layout optimization problems, most of the previous researches considering the position and/or the length of the stiffener as design variables dealt with structures having just simple convex shapes such as a square or rectangle. The reason is concave shape structures have difficulties ill formulating geometry constraints. In this paper, a new geometry constraint handling technique, which can define both convex and concave feasible lesions and measure a degree of geometry constraint violation, is proposed. Evolution strategies (ESs) is utilized as an optimization tool. In addition, the constraint-handling technique of EVOSLINOC (EVOlution Strategy for scalar optimization with Lineal and Nonlinear Constraints) is utilized to solve constrained optimization problems. From a numerical example, the proposed geometry constraint handling technique is verified and proves that the technique can easily be applied to structures in net only convex but also concave shapes, even with a protrusion or interior holes.

• Journal of Trauma and Injury
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• 제25권4호
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• pp.209-216
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• 2012

Purpose: The objectives of this study are to classify chronic subdural hematomas based on brain computerized tomographic scan (CT scan) findings and to determine the mechanism of evolution and treatment methods. Methods: One hundred thirty-nine patients who were diagnosed with a chronic subdural hematoma and who available for follow up assessment 6 months post-surgery were analyzed retrospectively. The presence of trauma and past medical history were reviewed and evaluation criteria based on brain CT scan findings were examined. Results: Initial brain CT scans revealed a chronic subdural hematoma in 106 patients, a subdural hygroma in 24 patients, and an acute subdural hematoma in 9 patients. In all cases where the initial acute subdural hematoma had progressed to a chronic subdural hematoma, final was a hypo-density chronic subdural hematoma. In case where the initial subdural hygroma had progressed to a chronic subdural hematoma, the most cases of hematoma were hyper-density and mixed-density chronic subdural hematoma. In total, 173 surgeries were performed, and they consisted of 97 one burr-hole drainages, 70 two burr-hole drainages and 6 craniotomies. Conclusion: This study demonstrates that rebleeding and osmotic effects are mechanisms for enlarging of a chronic subdural hematoma. In most cases, one burr-hole drainage is a sufficient for treatment. However, in cases of mixed or acute-on-chronic subdural hematomas, other appropriate treatment strategies are required.

• 인터넷정보학회논문지
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• 제13권4호
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• pp.53-62
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• 2012

객체분할은 영상처리와 컴퓨터비전분야의 상당히 어려운 연구대상이다. 그레이스케일 영상에 대한 영상분할은 매우 많은 방법이 발표되었으며 다양한 영상특징과 처리방법이 제시되었다. 이러한 방법들은 대개 자연상태의 칼라 영상에 적용되기 어렵다. 본 논문에서는 기하학적인 Active Contour 모델의 수정된 형태, 즉 거리정규화레벨셋(distance regularized level set evolution: DRLSE)을 이용한 방법을 제시하여 스피드 함수가 이러한 칼라요소를 반영하도록 하였으며 실험결과 정확성과 시간효율성에 있어서 우수한 결과를 보여주었다.

• Journal of Astronomy and Space Sciences
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• 제38권1호
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• pp.65-82
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• 2021

For the vast majority of geostationary satellites currently in orbit, station keeping activities including orbit determination and maneuver planning and execution are ground-directed and dependent on the availability of ground-based satellite control personnel and facilities. However, a requirement linked to satellite autonomy and survivability in cases of interrupted ground support is often one of the stipulated provisions on the satellite platform design. It is especially important for a geostationary military-purposed satellite to remain within its designated orbital window, in order to provide reliable uninterrupted telecommunications services, in the absence of ground-based resources due to warfare or other disasters. In this paper we investigate factors affecting the robustness of a geostationary satellite's orbit in terms of the maximum duration the satellite's station keeping window can be maintained without ground intervention. By comparing simulations of orbit evolution, given different initial conditions and operations strategies, a variation of parameters study has been performed and we have analyzed which factors the duration is most sensitive to. This also provides valuable insights into which factors may be worth controlling by a military or civilian geostationary satellite operator. Our simulations show that the most beneficial factor for maximizing the time a satellite will remain in the station keeping window is the operational practice of pre-emptively loading East-West station keeping maneuvers for automatic execution on board the satellite should ground control capability be lost. The second most beneficial factor is using short station keeping maneuver cycle durations.

• 한국IT서비스학회지
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• 제20권5호
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• pp.105-118
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• 2021

As we enter the era of the 4th industrial revolution, information and communication technologies, including artificial intelligence and big data, are converging throughout society. Especially, as the importance of the social foundation of hyper-connection grows, the social influence of IoT, a network of connecting objects, people, and various entities, is also gradually expanding. In addition, as a pandemic, COVID-19, continues, interests in untact-oriented technology and service development are growing more than ever, and each company is trying to establish a core competency strategy to gain an edge in competition in the changing society. This study is a case study centered on Dawon DNS, a company that provides an IoT-based AI smart plug platform. Dawon DNS is broadening its services while developing products by applying advanced technologies, and this study is aiming to investigate the core competencies of the business evolution process. The obtained result of this study will provide implications for companies to become more competitive by suggesting the attitudes and strategies that startups should have during the transforming business environment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권2호
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• pp.335-352
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• 2023

When solving multi-objective optimization problems, the blindness of the evolution direction of the population gradually emerges with the increase in the number of objectives, and there are also problems of convergence and diversity that are difficult to balance. The many- objective optimization problem makes some classic multi-objective optimization algorithms face challenges due to the huge objective space. The sine cosine algorithm is a new type of natural simulation optimization algorithm, which uses the sine and cosine mathematical model to solve the optimization problem. In this paper, a knee-driven many-objective sine-cosine algorithm (MaSCA-KD) is proposed. First, the Latin hypercube population initialization strategy is used to generate the initial population, in order to ensure that the population is evenly distributed in the decision space. Secondly, special points in the population, such as nadir point and knee points, are adopted to increase selection pressure and guide population evolution. In the process of environmental selection, the diversity of the population is promoted through diversity criteria. Through the above strategies, the balance of population convergence and diversity is achieved. Experimental research on the WFG series of benchmark problems shows that the MaSCA-KD algorithm has a certain degree of competitiveness compared with the existing algorithms. The algorithm has good performance and can be used as an alternative tool for many-objective optimization problems.

• Earthquakes and Structures
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• 제22권5호
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• pp.487-502
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• 2022

China is prone to earthquake disasters, and the higher seismic performance is required by many existing civil buildings. And seismic evaluation and retrofit are effective measures to mitigate seismic hazards. With the development of performance-based seismic design and diverse retrofit technology for buildings, advanced evaluation methods and retrofit strategies are in need. In this paper, we introduced the evolution of seismic performance objectives in China combined with performance-based seismic design. Accordingly, multi-phase evaluation methods and comprehensive seismic capacity assessment are introduced. For buildings with seismic deficiency or higher performance requirements, the retrofit technologies are categorized into three types: component strengthening, system optimization, and passive control. Both engineering property and social property for the retrofit methods are discussed. The traditional seismic retrofit methods usually are costly and disturbing, and for example in Beijing, seismic strengthening costs approx. 1000 RMB/m² (for 160 USD/m²), for hospital building even more expensive as 5000 RMB/m²(for 790 USD/m²). So cost-efficient and little disturbance methods are promising techniques. In the end, some opinions about the retrofit strategy and schemes category are shared and wish to discuss the situation and future of seismic retrofit in China.

• 한국경제지리학회지
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• 제1권2호
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• pp.103-134
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• 1998

본 연구는 우리 나라의 대표적인 이벤트관광으로 성장한 진도 영등제를 사례로 최근 지역개발 및 관광정책에서 중요성이 강조되고 있는 이벤트관광의 성장과정과 활성화 방안을 관광지리학적인 관점에서 고찰하였다. 1998년 현재 21회를 맞이한 영등졔는 영등살에 바닷물이 빠짐으로써 나타나는 장소적 매력요인이 다른 지역축제와 뚜렷하게 차별화된다는 점과 원형에 가깝게 전송되어 온 다양한 무속 및 민속문화 자원이 풍부하다는 점에서 그 개발 잠재력이 매우 높은 축제이다. 1978년도부터 개최되기 시작한 영등제는 프로그램과 예산, 참가인원 및 관광수익등 규모면에 있어서 꾸준한 성장을 보여왔다. 개최기간도 1회의 당일 개최에서 3일로 연장되었고, 관공세력권도 꾸준한 확대되어 원거리의 수도권에 거주하는 관광객의 비율이 높은 편이다. 영등제를 더욱 활성화시키기 위해서는 영등제가 열리는 장소의 매력성을 이용한 지역이미지 창출, 민간주도형 추진체제의 강화, 적극적인 경영마인드의 도입, 진도군 주변관광지와의 연계방안, 지속적인 관광객 분석을 통한 시장세분화 등이 필요하다.

• 한국콘텐츠학회논문지
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• 제9권2호
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• pp.400-409
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• 2009

본 연구는 체육교과 진화에 관해 생태학적으로 조망해 보고 논의 하는데 그 목적이 있다. 이를 위해 2007년 개정 체육과 교육과정을 통해서 의미를 모색해보았다. 교육과정을 토대로 체육교과의 진화를 조망한 이유는 개정 체육과 교육과정에는 체육교육의 목표, 가치, 체육교육의 철학적 배경을 담고 있기 때문이다. 본 연구를 통해 타나난 결과는 다음과 같다. 첫째, 현장교사에 대한 역할 강화를 위한 적극적 지원이 강조되어야 한다. 둘째, 체육교과에서 전술이 강조되어야 한다. 셋째, 운동을 단순히 기능 혹은 운동신경수준이 아닌 가드너가 제시한 지능으로 해석하는 것이 필요하다. 넷째, 체육교과의 정상화를 위해서는 현재 고등학교 2, 3학년에서 체육교과 필수 지정에 대한 노력이 필요하다.