• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.8A
• /
• pp.1104-1114
• /
• 2000

If the control system that works important job fails, economical loss occurred. Hence, to guarantee high reliability, it must be duplicated. In the case of traditional duplication mechanism, dedicated operating system with duplication functions were built. This required much development and maintenance cost. They can be saved, if we use commercial operating system and its development environment.This paper proposes a duplication mechanism for the system based on commercial 0S. The system that explained in this paper is BSC(Base Station Controller). The duplicated BSC system uses concurrent write memory for synchronization and VxWorks as an operating system. We propose how the task supporting duplication functions is executed without delay and preemption, how to synchronize standby's memory with active' s, and how to use concurrent-write memory easily with VxWorks' s partition. We also describe the takeover procedure when the active detects its hardware fault and when the standby recognizes the failure of the active.

• Journal of KIISE:Information Networking
• /
• v.34 no.5
• /
• pp.360-369
• /
• 2007

Since wireless sensor networks consist of nodes with the constrained battery, it is important to construct the topology performing energy-efficient routing while maximizing the whole network lifetime. Previous works related to this do not take into consideration the specific communication pattern in wireless sensor networks. In this paper, we propose a novel routing algorithm, called Up-Down Tree(UDT), which first constructs the tree topology based on distance and then adjusts the transmission range determined by the two different phases, tree setup and data gathering, to adapt the specific communication pattern in wireless sensor networks. Therefore, the UDT can improve energy efficiency, maximize the network lifetime, and block network partition Simulation results show that the UDT has the improved energy efficiency by constructing the optimal topology.

• Journal of the Korea Concrete Institute
• /
• v.18 no.1 s.91
• /
• pp.101-108
• /
• 2006

Accurate prediction of time-dependent column shortening is essential for tall buildings in both strength and serviceability aspects. The uncertainty associated with assumed values for concrete properties such as strength, creep, and shrinkage coefficients should be considered for the prediction of time-dependent column shortening of tall concrete buildings. In this study, the column shortenings of 41-story tall concrete building are predicted using monte carlo simulation technique based on the probabilistic analysis. The probabilistic column shortenings considering confidence intervals are compared with the actual column shortenings by field measurement. The time-dependent strains measured at tall bearing wall building were generally lower than the predicted strains and the measured values fell within a range ${\mu}-1.64$, confidence level 90%.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.5
• /
• pp.1-7
• /
• 2009

When constructing various mobile networks including sensor networks, the problem of finding the layout or graph to interconnect the terminals or nodes of the network may come up. Providing a common scheme that can be applied to the kind of problems, and formulating the bounds of the run time and the result of the algorithm from the scheme, one may evaluate precisely the plan of constructing analogous network systems. This paper, dealing with EMST(Euclidean Minimum Spanning Tree) that represents such problems, provides the scheme for constructing EMST by parallel processing over distributed environments, and the ground for determining the maximum difference of the layout or the graph produced from the scheme: the difference from EMST. In addition, it provides the upper bound of the run time of the algorithm from the scheme.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.6
• /
• pp.89-95
• /
• 2008

In this paper, we designed a low power face detection hardware and analysed its power consumption. The face detection hardware was fabricated using Samsung 0.18um CMOS technology and it can detect multiple face locations from a 2-D image. The hardware is composed of 6 functional modules and 11 internal memories. We introduced two operating modes(SLEEP and ACTIVE) to save power and a clock gating technique was used at two different levels: modules and registers. In additional, we divided an internal memory into several pieces to reduce the energy consumed when accessing memories, and fully utilized low power design option provided in Synopsis Design Compiler. As a result, we could obtain 68% power reduction in ACTIVE mode compared to the original design in which none of the above low power techniques were used.

• 한국HCI학회:학술대회논문집
• /
• 2006.02b
• /
• pp.795-802
• /
• 2006

현대의 소비자는 더 이상 단순히 감성적 소구에 의해서나 기술적 기능을 제공하는 것으로 제품을 구매하지 않는다. 제품의 결정은 사용자와 제품 간의 상호작용에 따른 정서, 인지, 행위 등에 의한 총체적인 경험에 의한 것이며, 그러한 소비자들의 경험은 지리적, 역사적 전통으로 고착된 문화적 특성이 제품을 통한 사용자 경험의 기저에서 작용함으로써 문화권 별, 국가 별로 각기 다르게 구성된다. 특별히 음식 문화는 어느 나라이든 자연 조건의 영향과 함께 오랜 역사 속에서 형성되었기 때문에 독특하고 다양한 문화적 차이를 지니고 있으며 이러한 문화적 차이는 냉장고 사용에 있어서 다양한 사용행태를 구분 짓는다. 따라서 본 연구를 통해 식품 종류에 의한 영향뿐 아니라 내부 공간 활용의 패턴, 냉장고 환경 설정에 대한 능동적인 태도, 냉장고에서 제공하는 파티션이나 옵션에 대한 수용 정도, 식품의 정리 원칙에 대한 준수 정도 등에 따른 사용행태 간의 차이점을 발견하고, 차별적 사용행태의 기저에 존재하는 문화적 요인을 분석하여 문화적 차이가 사용자의 경험에 영향을 끼치게 됨으로 인하여 냉장고 디자인에 어떠한 변화를 초래하는지 그 연관성을 밝혀내고자 한다. 보다 실제적인 용도로 활용 가능하도록 냉장고 제작의 상업적인 측면을 고려하여 냉장고 내상의 레이아웃에 중점을 두어 본 연구를 진행하였다. 본 연구는 설문과 현장 관찰을 통해 정량적 관찰을 중심으로 분석하였다. 두 국가의 문화 비교를 위한 설문은 이미 여러 연구자료에 의해 검증된 Trompenaars의 문화 변수를 바탕으로 제작 하였다. 또한 정량적 연구에서 발견될 수 없는 문화권 별 여러 특징들에 대한 데이터를 구체적으로 수집하기 위하여 정성적인 연구 방식의 일환으로 실제 관찰 및 사용자 인터뷰를 실시하였으며, 이를 통하여 현상의 원인 및 사용자의 의도를 파악하도록 연구를 진행하였다.

• The Journal of the Korea Contents Association
• /
• v.16 no.7
• /
• pp.667-680
• /
• 2016

As distributed computing platforms like Hadoop MapReduce have been developed, it is necessary to perform the conventional query processing techniques, which have been executed in a single computing machine, in distributed computing environments efficiently. Especially, studies on similarity join query processing in distributed computing environments have been done where similarity join means retrieving all data pairs with high similarity between given two data sets. But the existing similarity join query processing schemes for distributed computing environments have a problem of skewed computing load balance between clusters because they consider only the data transmission cost. In this paper, we propose Matrix-based Load-balancing Algorithm for efficient similarity join query processing in distributed computing environment. In order to uniform load balancing of clusters, the proposed algorithm estimates expected computing cost by using matrix and generates partitions based on the estimated cost. In addition, it can reduce computing loads by filtering out data which are not used in query processing in clusters. Finally, it is shown from our performance evaluation that the proposed algorithm is better on query processing performance than the existing one.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.12
• /
• pp.1884-1891
• /
• 2016

With the various usage of civil drones, such as hobby, filmmaking and surveillance, the need for technology that safely reconstructs software for target application domains has been increasingly rising. In order to support a reliable software integration of avionic systems, the ARINC 653 standard has been proposed and adapted mainly on manned aircrafts. Therefore, applying ARINC 653 on civil drones could be desirable. Though, various researches on implementing ARINC 653 has been conducted, there are still additional requirements to apply ARINC 653 to civil drones that use various platforms and have a wide range of use. In this paper, taking account of these requirements, we implement a portable and extensible ARINC 653 and analyze its performance. We offer the portability with the OS abstraction layer that reduces dependency on a specific operating system, and provide the design that can extend internal functions, such as partition scheduler and process scheduler.

• The Journal of the Korea Contents Association
• /
• v.6 no.1
• /
• pp.23-30
• /
• 2006

A clustering method for temporal data takes a model-based approach. This uses automata based model for each cluster. It is necessary to construct global models for a set of data in order to elicit individual models for the cluster. The preparation for building individual models is completed by determining the number of clusters inherent in the data set. In this paper, BIC(Bayesian Information Criterion) approximation is used to determine the number clusters and confirmed its applicability. A search technique to improve efficiency is also suggested by analyzing the relationship between data size and BIC values. A number of experiments have been performed to check its validity using artificially generated data sets. BIC approximation measure has been confirmed that it suggests best number of clusters through experiments provided that the number of data is relatively large.

• The Journal of the Korea Contents Association
• /
• v.7 no.6
• /
• pp.22-30
• /
• 2007

Most real word systems such as world economy, stock market, and medical applications, contain a series of dynamic and complex phenomena. One of common methods to understand these systems is to build a model and analyze the behavior of the system. In this paper, we investigated methods for best clustering over time series data. As a first step for clustering, BIC (Bayesian Information Criterion) approximation is used to determine the number of clusters. A search technique to improve clustering efficiency is also suggested by analyzing the relationship between data size and BIC values. For clustering, two methods, model-based and similarity based methods, are analyzed and compared. A number of experiments have been performed to check its validity using real data(stock price). BIC approximation measure has been confirmed that it suggests best number of clusters through experiments provided that the number of data is relatively large. It is also confirmed that the model-based clustering produces more reliable clustering than similarity based ones.