• 융합신호처리학회논문지
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• 제9권3호
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• pp.224-229
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• 2008

In the paper, a new Constraint algorithm is proposed to solve the fan-in problem occurred in the encoding circuitry of an ADC. The Flash ADC architecture uses a Double-Base Number System(DBNS). The DBNS has been known to represent the Multidimensional Logarithmic Number System (MDLNS) used for implementing the multiplier accumulator architecture of FIR filter in Digital Signal Processing (DSP) applications. The authors use the DBNS with the base 2 and 3 in designing ADC encoder circuits, which is called as Double Base Integer Encoder(DBIE). A symmetric map is analyzed first, and then asymmetric map is followed to provide addition ready DBNS for DSP circuitry. The simulation results of the DBIE circuits in 6-bit and 8-bit ADC show the effectiveness of the Constraint algorithm with $0.18{\mu}m$ CMOS technology. The DBIE yields faster processing speed compared to the speed of Fat Tree Encoder (FAT) circuits by 17% at more power consumption by 39%.

• 한국도서관정보학회지
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• 제20권
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• pp.351-381
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• 1993

The purpose of this study is to analyze the various processes and patterns to build or synthesize class numbers in the 800 class of the Dewey Decimal Classification, Edition 20(1989). The results of the analysis are as follows: 1. The 800(Literature and rhetoric) class in the DDC system is the main class added analytico-synthetic principle positively to an enumerative scheme. 2. The facets to be a n.0, pplied in literature are language literary form literary period ; kind, scope, or medium ; notation 08(collection) or 09(criticism) literary feature, subject, author, etc. 3. In the 800 class, there are the five tables of precedence for literary forms aspects ; specific kinds of persons ; literary, period in relation to the aspects for works treating more than one literary form subforms, aspects and literary periods in the works treating a specific literary form. 4. The basic number synthesis of literary works proceeds through the various facets in the following sequence, as far as necessary for the item : base no. + literary form + literary time or period + kind, scope, or medium + notation 08 or 09 + subform + additional notation from T3C and other tables. 5. In view of the multiplicity of facets, their synthesis formulas take the following order : (1) Works about the literature : base no.(schedule) + language(T6) or form(T3B) (2) Works by or about individual author : base no.(schedule) + form (T3A) + period(schedule) + subform(T3A) (3) Works by or about more than one author, not restricted by language facet : base no.(schedule) + period(T1) ; base no.(schedule) + kind, scope, medium(T3B), or feature(T3C), or person(T5). (4) Works by or about more than one author, restricted by language facet : base no.(schedule) + form (T3B) + period(schedule) + subform(T3B) + notation 08 or 09(T3B) ; base no.(schedule) + notation 08 or 09(T3B) + 9(T3C) + area notation(T2) : base no.(schedule) + form (T3B) + notation 008 or 009(T3B) : base no.(schedule) + form (T3B) + kind, scope, medium(T3B) + notation 08 or 09(T3B) + period(schedule). (5) Affiliated literatures for which period numbers are not us base no.(schedule) + form (T3A or T3B), or notation 08 or 09(T3B) : base no.(schedule) + kind, scope, medium(T3B), feature(T3C), or person(T5) 6. The problems in the number building of the 800 class are the complexity and difficulty of number synthesis, the intrinsic weakness of from distinction and the inconvenience of retrieval inherent in the form class. In order to solve these problems, therefore, the citation orders and methods of DDC should be improved and synthesis patterns simplified from the point of view of its applicability and its usefulness in the "literature class".

• 신재생에너지
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• 제3권1호
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• pp.13-19
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• 2007

A triangular fin with variable fin base thickness and base height is analyzed and optimized for the fixed fin base height using a two-dimensional analytical method. At the middle of the fin length, the variation of the temperature along the fin height is listed. The influences of the fin length, base thickness and base height on the heat loss and fin efficiency are analyzed, The optimum heat loss, corresponding optimum efficiency and optimum fin length as a function of the fin base thickness are presented. The optimum heat loss and optimum fin tip length as a function of the convection characteristic number are represented.

• 전자공학회논문지
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• 제52권3호
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• pp.19-24
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• 2015

본 논문에서는 massive multiple-input multiple-output (MIMO) 기반의 wireless powered communication network (WPCN)에서 에너지 효율을 향상시키기 위한 기지국 안테나 수 최적화 기법을 제안한다. 제안하는 기법은 massive MIMO 시스템의 채널 hardening 특성을 이용하여 채널 이득을 안테나 수에 대한 식으로 근사한다. 그리고 근사화 된 최적화 문제에 편미분을 적용한 후 Lambert-W 함수를 이용하여 최적해를 closed form으로 찾는다. 모의실험을 통해 제안하는 기법의 근사 과정과 최적화 문제를 해결하는 방법이 적절함을 보이고, closed form 해가 exhaustive search 방법으로 찾은 해와 오차가 크지 않음을 확인한다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.133-138
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• 1997

For a long time, a number of alarm processing techniques have been researched to reduce the number of actuated alarms for operators to deal with effectively during the abnormal as well as the normal conditions. However, the strategy that the only systems with a few clear technologies should be used as a part of an alarm annunciation system has been adopted considering the effectiveness and the reliability in actual alarm processing systems. Therefore, alarm processing systems have difficult knowledge-base maintenance problems and limited expansion or enhancement defects. To solve these shortcomings, the integrated knowledge-base which can express the general information related to all the alarm processing techniques is proposed and its management tool, Knowledge Input Tool for Alarm (KIT-A) which can handle the data of the knowledge-base efficiently is developed. Since the integrated knowledge-base with KIT-A can manipulate all the alarm information without the modification of alarm processing system itself, it is expected to considerably advance the overall capability of maintenance and enhancement of the alarm processing systems.

• Earthquakes and Structures
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• 제10권5호
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• pp.1067-1087
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• 2016

In this paper, a decoupled proportional-integral-derivative (PID) control approach for seismic control of smart structures is presented. First, the state space equation of a structure is transformed into modal coordinates and parameters of the modal PID control are separately designed in a reduced modal space. Then, the feedback gain matrix of the controller is obtained based on the contribution of modal responses to the structural responses. The performance of the controller is investigated to adjust control force of piezoelectric friction dampers (PFDs) in a benchmark base isolated building. In order to tune the modal feedback gain of the controller, a suitable trade-off among the conflicting objectives, i.e., the reduction of maximum modal base displacement and the maximum modal floor acceleration of the smart base isolated structure, as well as the maximum modal control force, is created using a multi-objective cuckoo search (MOCS) algorithm. In terms of reduction of maximum base displacement and story acceleration, numerical simulations show that the proposed method performs better than other reported controllers in the literature. Moreover, simulation results show that the PFDs are able to efficiently dissipate the input excitation energy and reduce the damage energy of the structure. Overall, the proposed control strategy provides a simple strategy to tune the control forces and reduces the number of sensors of the control system to the number of controlled stories.

• Wind and Structures
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• 제12권1호
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• pp.49-61
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• 2009

A method is presented to estimate the form drag and the base pressure on a triangular cylinder in the presence of blockage effect. The Strouhal number, which is found to increase with the flow constriction experimentally by Ramamurthy & Ng (1973), may be decoupled from the blockage effect when re-defined by using the velocity at flow separation and a theoretical wake width. By incorporating this wake width into the momentum equation by Maskell (1963) for the confined flow, a relationship between the form drag and the base pressure is derived. Independently, the experimental data of surface pressure from Ramamurthy & Lee (1973) are found to be independent of the blockage effect when expressed in terms of a modified pressure coefficient involving the pressure at separation. Using the potential flow model by Parkinson & Jandali (1970) and its subsequent development in Yeung & Parkinson (2000) for the unconfined flow, a linear relation between the pressure at separation and the form drag is formulated. By solving the two equations simultaneously with a specified blockage ratio and an apex angle of the triangular cylinder, the predictions of the drag and the base pressure are in reasonable agreement with experimental data. A new theoretical relationship for the Strouhal number, pressure drag coefficient and base pressure proposed in this study allows the confinement effect to be appropriately taken into consideration. The present approach may be extended to three-dimensional bluff bodies.

• 한국정보통신학회논문지
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• 제6권8호
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• pp.1336-1345
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• 2002

데이터웨어하우스에서 실체뷰는 사용자의 정보처리 요구에 신속하게 응답하기 위한 주요한 수단이다. 데이터웨어하우스내에 실체뷰의 개수가 많을수록 사용자의 질의요구를 실체뷰내에서 처리할 수 있는 확률이 높아지므로 신속한 응답이 가능하다. 데이터웨어하우스내에 유지할 수 있는 실체뷰의 개수에 대한 주요 제약은 기본릴레이션의 변화에 기인하는 실체뷰 갱신시간이다. 본 논문에서는 MIN/MAX 함수를 포함하는 실체뷰에 대해서 기본릴레이션의 MIN/MAX값의 변화가 빈번할 경우에도 실체뷰 갱신시간을 절약할 수 있는 효율적인 실체뷰 갱신정책을 제안한다. 기본릴레이션의 MIN/MAX값의 변경을 삽입/삭제연산으로 구분하여 실체뷰를 갱신하면 실체뷰의 MIN/MAX값 갱신을 위하여 기본릴레이션에 접근해야 할 횟수가 줄어든다.

• 설비공학논문집
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• 제20권7호
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• pp.455-461
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• 2008

A reversed trapezoidal fin with variable fin base thickness is optimized using a two-dimensional analytical method. For the fin base boundary condition, instead of a constant temperature, heat transfer from the inside fluid to the fin base is considered. Heat loss from the fin tip is not ignored. The maximum heat loss, corresponding optimum fin effectiveness, fin length and base height are presented as a function of the fin base thickness, shape factor and volume.

• Earthquakes and Structures
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• 제4권4호
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• pp.341-363
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• 2013

Earthquake response calculation, parametric analysis and seismic parameter optimization of base-isolated structures are some critical issues for seismic design of base-isolated structures. To calculate the earthquake responses for such non-symmetric and non-classical damping linear systems and to implement the earthquake resistant design codes, a modified complex mode superposition design response spectrum method is put forward. Furthermore, to do parameter optimization for base-isolation structures, a graphical approach is proposed by analyzing the relationship between the base shear ratio of a seismic base-isolation floor to non-seismic base-isolation one and frequency ratio-damping ratio, as well as the relationship between the seismic base-isolation floor displacement and frequency ratio-damping ratio. In addition, the influences of mode number and site classification on the seismic base-isolation structure and corresponding optimum parameters are investigated. It is demonstrated that the modified complex mode superposition design response spectrum method is more precise and more convenient to engineering applications for utilizing the damping reduction factors and the design response spectrum, and the proposed graphical approach for parameter optimization of seismic base-isolation structures is compendious and feasible.