• Journal of the Korea Concrete Institute
• /
• v.28 no.3
• /
• pp.299-308
• /
• 2016

This paper presents an investigation of the mechanical and microstructural properties on hardened samples that were synthesized using blended binder(fly ash(FA) and blast furnace slag cement(BFSC)), alkali activator and sea water or distilled water. Binders were prepared by mixing the FA and BFSC in different blend weight ratios of 6:4, 7:3 and 8:2. Sodium hydroxide and sodium silicate were used 5 wt% of binder, respectively, as an alkaline activator. The compressive strength and absorption were measured at the age of 3, 7 and 28 days, and the XRD, TGA and MIP tests were performed at the age of 28 days. An increase in the content of BFSC leads to an increase in the quantities of ettringite and C-S-H formed, regardless of the type of mixing water. And it also shows higher strength due to the reduction of pores larger than ~50 nm. All hardened samples in this study have common hydration products of C-S-H, $Ca(OH)_2$ and calcite. Hydrocalumite of all reaction products formed was only present in hardened sample mixed with sea water. For each FA/BFSC mixing ratio, the compressive strength of hardened sample mixed with sea water was similar to that mixed with distilled water. It is proposed that the slight increase of strength of samples mixed with sea water is mainly due to the presence of hydrocalumite phase containing chlorine ion, contributing to the change of total porosity and pore size distribution in samples.

• The KIPS Transactions:PartC
• /
• v.9C no.1
• /
• pp.97-106
• /
• 2002

In 3GPP2 standard, MIP is used and a PDSN performs the function of FA to support macro mobility. When a MS is roaming from a PDSN area to another, the mobility supported is called macro mobility, while it is called micro mobility when a MS is roaming from a RN area to another in a PDSN area. Since a PDSN performs the function of FA in 3GPP2 standard, it is possible to support mobility but its mechanism is actually for supporting macro mobility, not for micro mobility, thus it is weak in processing fast and seamless handoff to support micro mobility. In this paper, we suggest the seamless handoff algorithm barred on multicast group mechanism to support micro mobility. Depending on the moving direction and velocity of a MS, the suggested algorithm constructs a multicast group of RNs on the forecasted MS's moving path, and maximally delays RNs'joining to a multicast group to increase the network efficiency. Moreover, to resolve the buffer overhead problem of the existent multicast scheme, the algorithm suggests that each RN buffers data only after the forecasted handoff time. To prove deadlock freeness and liveness of the algorithm. we use state transition diagrams, a Petri-net modeling and its reachability tree. Then, we evaluate the performance by simulation.

• Proceedings of the KIEE Conference
• /
• 2008.04a
• /
• pp.79-80
• /
• 2008

본 논문은 FPGA 기반에서 실수형 프로세서의 설계 및 구현에 대한 내용과 이를 이용하여 휴머노이드 로봇 팔의 위치제어를 위한 PD 제어기반의 신경회로망 제어기의 구현에 대한 내용이다. 설계된 프로세서는 명령어 기반의 처리를 통해 산술 연산 뿐만 아니라 로봇의 제어에 사용되는 외부 모듈의 사용이 가능하도록 설계하였으며, 신경회로망 구현에 사용되는 지수함수를 효율적으로 근사화하기 위한 Taylor series를 이용한 알고리즘을 하드웨어 레벨에서 구현하였다. 휴머노이드 로봇 팔의 위치 추종을 위해 고전적인 PD 제어기를 설계하고 PD 기반의 신경회로망 제어기를 설계하였다. 로봇 팔의 6축 제어를 위한 신경회로망 제어기에 요구되는 많은 연산을 감당하도록 하기 위해 설계된 프로세서를 통해 정의된 프로그래밍언어로 제어 프로그램을 작성하였다. PD 제어기와 PD 기반의 신경회로망 제어기를 하드웨어에 설계하여 로봇팔의 위치 추종을 실험하였으며 성능을 비교 검증하였다. 프로세서는 Altera의 Stratix II EP2S180 DSP development board에 구현되었으며 실험적으로 25MIPS의 성능을 가지는 것으로 나타났다.

• Proceedings of the Acoustical Society of Korea Conference
• /
• autumn
• /
• pp.169-172
• /
• 1999

본 논문에서는 EVRC 음성 부호화 시스템을 $OakDSPCore^{\circledR}$를 기반으로 설계된 C&S Technology사의 CSD17C00 칩을 이용하여 전 과정을 어셈블리어로 실시간 구현하였다. 구현된 EVRC 음성 부호화기는 최대의 계산량을 요구하는 8kbps일때 잡음제거 알고리즘을 제외한 인코더부분이 평균 22.5MIPS 이며, 디코더부분은 약 3.35MIPS의 복잡도를 나타낸다. 사용된 메모리양은 프로그램 ROM 10.8K words 데이터 ROM(table) 6.72K words 및 RAM 2.94K words이다. 구현된 EVRC 음성 부호화기는 북미 표준화 기구인 TIA(Telecommunications Industry Association)에서 제공하는 19 개의 test 백터들을 모두 통과하였다.

• Journal of Korean Society for Quality Management
• /
• v.36 no.2
• /
• pp.28-35
• /
• 2008

This study deals with an Excel-based scheduling system for a small and medium sized manufacturing factory without sufficient capability for managing full-scale information systems. The factory has the bottleneck with identical machines and unique batching characteristics. The scheduling problem is formulated as a variation of the parallel-machine scheduling system. It can be solved by a two-phase method: the first phase with an ant colony optimization (ACO) heuristic for order grouping and the second phase with a mixed integer programming (MIP) algorithm for scheduling groups on machines.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.30 no.2
• /
• pp.143-156
• /
• 2005

Facility location planning (FLP) problem is the strategic level planning in supply chain. The FLP is significantly affected by the operation time of each facility. In most of the FLP researches, operation time of facility has been treated as a fixed value. However, the operation time is not a static factor in real situations and the fixed operation time may lead unrealistic FLP. In this paper, a mixed integer programming (MIP) model is proposed for solving the 3-stage FLP problem and operation times are adjusted by the results from the simulation model and an iterative approach combining the analytic model and simulation model is proposed to obtain more realistic operation plans for FLP problems.

• Management Science and Financial Engineering
• /
• v.6 no.2
• /
• pp.29-45
• /
• 2000

We consider the design of a two-level telecommunication network having logical full-mesh/star topology, with the implementation of conduit systems taken together. The design problem is then viewed as consisting of three subproblems: locating hub facilities, placing a conduit network, and installing cables therein to configure the logical full-mesh/star network. Without partitioning into subproblems as done in the conventional approach, the whole problem is directly dealt with in a single integrated framework, inspired by some recent successes with the approach. We successfully formulate the problem as a variant of the classical multicommodity flow model for the fixed charge network design problem, aided by network augmentation, judicious commodity definition, and some flow restrictions. With our optimal model, we solve some randomly generated sample problems by using CPLEX MIP program. From the computational experiments, it seems that our model can be applied to the practical problem effectively.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.52-55
• /
• 1999

다중 전송율(16, 24, 32, 40kbps)을 제공하는 G.726 부호화기는 ADPCM (Adaptive Differential Pulse Code Modulation) 부호화법을 사용한다. 본논문에서는 G.726 ADPCM 알고리즘을 C&S Technology에서 개발한 음성 신호 처리를 위한 범용 DSP인 CSD17C00A 칩을 이용하여 실시간 응용이 가능하도록 구현하였다. G.726에 대한 양방향 평가는 Codec Loopback test을 통해 수행되었으며, W-T에서 제공한 테스트 절차에 따라 평가되었다. 본 논문에서 구현된 G.726 부호화기는 평균 11 MIPS의 계산 속도를 갖고, 프로그램 메모리 크기는 2.8K Words이고, 데이터 메모리 크기는 550 Words 를 필요로 하였다.

• Journal of Korean Institute of Industrial Engineers
• /
• v.32 no.2
• /
• pp.98-103
• /
• 2006

In this research, the single machine capacitated lot-sizing and scheduling problem with sequence- dependent setup costs and setup times (CLSPSD) is considered. This problem is the extension of capacitated lot-sizing and scheduling problem (CLSP) with an additional assumption on sequence-dependent setup costs and setup times. The objective of the problem is minimizing the sum of production costs, inventory holding costs and setup costs satisfying customers' demands. It is known that the CLSPSD is NP-hard. In this paper, the MIP formulation is presented. To handle the problem more efficiently, a conceptual model is suggested, and one of the well-known meta-heuristics, the simulated annealing approach is applied. To illustrate the performance of this approach, various instances are tested and the results of this algorithm are compared with those of the CLPEX. Computational results show that this approach generates optimal or nearly optimal solutions.

• Biomedical Science Letters
• /
• v.18 no.4
• /
• pp.435-437
• /
• 2012

House dust mite (HDM) is important in the pathogenesis of allergic diseases including asthma and atopic dermatitis. Dermatophagoides pteronissinus (Dp) is one of major HDM allergens. In this study, we investigated that Dp extract (DpE) affects on the chemotactic activity of monocytes isolated from the peripheral blood. DpE inhibited the migration of human monocytes in response to CC chemokines such as MIP-$1{\alpha}$, RANTES, HCC-4, MCP-1, and TARC. DpE did not alter the expression of CC chemokine receptors (CCRs) such as CCR1, CCR2, CCR3, CCR4, and CCR5. These results indicate that DpE blocks the chemotaxis of human monocytes and its mechanism is not involved in alteration of CCR expression. Better understanding of the effect of DpE on monocytes will enable elucidation of the role of Dp in the development of allergic diseases.