• 한국콘텐츠학회논문지
• /
• 제12권1호
• /
• pp.30-37
• /
• 2012

선형 비틀림 구조를 갖는 메모리 시스템은 SIMD 구조에 적합한 메모리 시스템으로써, 2차원 데이터 배열인 $M{\times}N$에서 임의의 위치로부터 임의의 간격을 갖고 다양한 접근형태들로, m개의 메모리 모듈들에서 n개의 데이터를 동시에 접근할 수 있다. 그러나 이러한 메모리 시스템은 논리적인 2차원 $M{\times}N$ 데이터 배열을 지원하기 위해 $m{\times}cells$의 물리적인 메모리 용량이 필요하지만, 적어도 (m-n)${\times}cells$만큼의 메모리 셀은 사용되지 않는다. 여기서 cells는 (M-1)/q+(N-1)/$p{\times}{\lceil}M/q{\rceil}+1$이다. 본 논문에서는 이러한 메모리 시스템의 모든 기능들을 수용하면서 t>0인 조건 하에 사용되지 않는 메모리 셀들 중 $(n{\times}t){\times}N/p$ 만큼을 n개의 처리기들에 지역 버퍼 메모리로 제공할 수 있는 방법을 제안한다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 D
• /
• pp.1777-1779
• /
• 1999

SMM is a dynamic noncontact electric force microscopy that allows simultaneous access to the electrical properties of molecular system such as surface potential, surface charge, dielectric constant and conductivity along with the topography. SNOAM is a new tool for surface imaging which was introduced as one application of AFM. Operated with non-contact forces between the optical fiber and sample as well as equipped with the piezoscanners, the instrument reports on surface topology without damaging or modifying the surface for measuring of optical characteristic in the films. Here we report our recent results of its application to nanoscopic study of domain structures and electrical functionality in organic thin films by SMM. Furthermore, we have illustrated the SNOAM image in obtaining the merocyanine dye films as well as the optical image.

• 한국IT서비스학회지
• /
• 제17권3호
• /
• pp.63-75
• /
• 2018

In this paper, we propose a testing method of the quality of device application effectively reflecting the necessity of increasing mobile device application quality test, and designed and developed it as a web system. We have studied traditional software testing methods for designing and developing a system. We have developed a next-generation alternative technology that can analyze and compensate for the weaknesses of the web and weaknesses of the Android in order to realize the access system and the responsive web system. As an example applied to the system, we analyzed the requirements of the system implementation and expressed the functions of the system through the use case diagram. The test scenarios were conducted by connecting 5,000 devices to each system using the existing HTTP polling method and the proposed web socket method. After setting the comparative group, the result of the proposed web management system was observed and compared through repeated tests. The research shows that the proposed web socket system has better performance than HTTP polling. The more the number of simultaneous processing of the devices, the lower the server stability but the better the time efficiency. In conclusion, the more the number of devices to be tested is, the more the number of devices can be effectively tested using the proposed web management system.

• 한국통신학회논문지
• /
• 제19권6호
• /
• pp.1046-1055
• /
• 1994

본 논문에서는 영상 신호처리에 적합한 고속 1 line VRAM을 ASIC화 설계하기 위하여 엑세스 시간특성 및 집적도가 우수한 3-TR dual-port 다이나믹 셀을 채용하여 메모리 코어를 설계하였다. 고속 파이프라인 동작을 위하여 서브어레이 1로부터 첫 행을 분리하였고, TM기 비트 라인에 데이터 래치 구조를 채용하여 한 번지의 동시 입.출력이 가능하도록 설계하였다. 주변 회로로 번지 선택기, 1/2V 전압 발생기를 각각 설계하여 개선된 동작특성을 확인한 후 1.5[ m] CMOS 설계규칙을 이용하여 ASIC화 설계하였다.

• 한국컴퓨터정보학회논문지
• /
• 제4권2호
• /
• pp.80-87
• /
• 1999

우리는 공동연구 PACS 환경을 이용하는 여러 가지 영상의학 응용을 제의한다. 전통적인, 거의 모든 의학이미지는 방사선학의 필름을 인쇄하였다. 그들 필름을 생산하는데 비용이 많이 들고 잘못되기가 쉽고 복사 보존이 일반적이다. 따라서, 이미지에 대한 동시 접근하는데는 이용 인원이 제한된다. 그러나 PACS(영상기록 및 통신시스템)에 내포된 장점은 매우 많고 작은 저장소, 저렴한 유지비용, 매우 효과적이고, 개발비용은 높은 편이나 매우 유연성이 있다. 이 연구는 네트워크 환경에서 홈PC를 위한 영상의 학 시스템이 영상의학의 대부분이 CATV 브로드케스팅 기술로써 고비용의 단독 회선과 하드웨어를 사용하였다. 그러나 이 시스템은 사이버 공간에서 상호영향의 여러 가지 형식을 통해 의사와 환자간의 협력에 있어 보다 나은 이용을 위한 흠PC 변화에 대하여 기여 할 것이다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
• /
• pp.327-330
• /
• 2000

The scanning Maxwell-stress microscopy (SMM) is a dynamic noncontact electric force microscopy that allows simultaneous access to the electrical properties of molecular system such as surface potential, surface charge, dielectric constant and conductivity along with the topography. The Scanning near-field optical / atomic force microscopy (SNOAM) is a new tool for surface imaging which was introduced as one application of the atomic force microscope (AFM). Operated with non-contact forces between the optical fiber and sample as well as equipped with the piezoscanners, the instrument reports on surface topology without damaging or modifying the surface for measuring of optical characteristic in the films. We report our recent results of its application to nanoscopic study of domain structures and electrical functionality in organic thin films by SMM. Furthermore, we have illustrated the SNOAM image in obtaining the merocyanine dye films as well as the optical image.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권1호
• /
• pp.149-168
• /
• 2015

In cognitive radio networks (CRNs), hybrid overlay and underlay sharing transmission mode is an effective technique for improving the efficiency of radio spectrum. Unlike existing works in the literature, where only one secondary user (SU) uses overlay and underlay modes, the different transmission modes should be allocated to different SUs, according to their different quality of services (QoS), to achieve the maximal efficiency of radio spectrum. However, hybrid sharing mode allocation for heterogeneous services is still a challenge in CRNs. In this paper, we propose a new resource allocation method for hybrid sharing transmission mode of overlay and underlay (HySOU), to achieve more potential resources for SUs to access the spectrum without interfering with the primary users. We formulate the HySOU resource allocation as a mixed-integer programming problem to optimize the total system throughput, satisfying heterogeneous QoS. To decrease the algorithm complexity, we divide the problem into two sub-problems: subchannel allocation and power allocation. Cutset is used to achieve the optimal subchannel allocation, and the optimal power allocation is obtained by Lagrangian dual function decomposition and subgradient algorithm. Simulation results show that the proposed algorithm further improves spectrum utilization with a simultaneous fairness guarantee, and the achieved HySOU diversity gain is a satisfactory improvement.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권3호
• /
• pp.1362-1376
• /
• 2016

A cloud computing system can be characterized by the provision of resources in the form of services to third parties on a leased, usage-based basis, as well as the private infrastructures maintained and utilized by individual organizations. To attain the desired reliability and energy efficiency in a cloud data center, trade-offs need to be carried out between system performance and power consumption. Resolving these conflicting goals is often the major challenge encountered in the design of optimization strategies for cloud data centers. The work presented in this paper is directed towards the development of an Energy-efficient and Performance-aware Cloud System equipped with strategies for dynamic switching of optimization approach. Moreover, a platform is also provided for the deployment of a Wind Farm CMS (Condition Monitoring System) which allows ubiquitous access. Due to the geographically-dispersed nature of wind farms, the CMS can take advantage of the cloud's highly scalable architecture in order to keep a reliable and efficient operation capable of handling multiple simultaneous users and huge amount of monitoring data. Using the proposed cloud architecture, a Wind Farm CMS is deployed in a virtual platform to monitor and evaluate the aging conditions of the turbine's major components in concurrent, yet isolated working environments.

• Journal of Communications and Networks
• /
• 제13권3호
• /
• pp.214-220
• /
• 2011

This paper attempts to address the effectiveness of physical-layer network coding (PNC) on the throughput improvement for multi-hop multicast in random wireless ad hoc networks (WAHNs). We prove that the per session throughput order with PNC is tightly bounded as ${\Theta}((n\sqrt{m}R(n))^{-1})$ if $m=(R^{-2}(n))$, where n is the total number of nodes, R(n) is the communication range, and m is the number of destinations for each multicast session. We also show that per-session throughput order with PNC is tight bounded as ${\Theta}(n^{-1})$, when $m={\Omega}(R^{-2}(n))$. The results of this paper imply that PNC cannot improve the throughput order of multicast in random WAHNs, which is different from the intuition that PNC may improve the throughput order as it allows simultaneous signal access and combination.

• 한국통신학회논문지
• /
• 제41권12호
• /
• pp.1700-1706
• /
• 2016

본 논문은 동시 전송 가능한 사물지능 통신 트래픽의 수를 늘리기 위하여 doubly truncated cyclic code shift keying (DTCCSK)을 활용한 대역 확산 알로하 기법을 제안한다. 제안하는 DTCCSK는 정사각형으로 표시되는 cyclic code shift keying 코드셋의 우측과 하단을 절삭함으로써 생성 가능하며, spreading factor와 심볼 길이를 자유롭게 설계할 수 있는 특징을 가진다. 또한 DTCCSK는 대역 확산 알로하의 변복조 기법으로 주로 사용되는 direct sequence 보다 높은 주파수 효율을 보이면서도 M-ary 시그널링 기법에 비해서는 낮은 구현 복잡도로 구현이 가능하다. 본 논문은 사물지능 통신을 위해 대역 확산 알로하를 채택한 S-band mobile interactive multimedia 표준을 참고하여 시뮬레이션 환경을 구성하였고 DTCCSK의 성능을 검증하였다.