• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.690-692
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• 2014

To identify characterization of a simple extension chamber that have the two internal partition, produce the curve to estimate the transmission loss without the computer analysis. For helpful for internal optimum design, identify the characteristic of internal partition on transmission loss. Made estimated transmission loss curve by function of relationship of internal partition and transmission. Check the similarity of predicted transmission loss and analysis transmission loss. Usage of the predicted transmission loss made by relationship of internal partition and transmission loss is good information to place the internal partition so as to maximize the transmission loss on target frequency at optimal design on muffler.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3A
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• pp.268-275
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• 2002

This paper proposes a region-based segmentation algorithm fur extracting a video object by using the cost of potential of frame-difference energies. In the first step of a region-based segmentation using spatial intensity, each frame is segmented into a partition of homogeneous regions finely so that each region does not contain the contour of a video object. The fine partition is used as an initial partition for the second step of spatio-temporal segmentation. In spatio-temporal segmentation, the homogeneity cost for each pair of adjacent regions is computed which reflects the potential between the frame-difference energy on the common contour and the frame-difference energy of the lower potential region of the two. The pair of adjacent regions whose cost is minimal then is searched. The two regions of minimum cost ale merged, which result in updating the partition. The merging is recursively performed until only the contours remain which have Same difference energies of high potential. In the fecal step of post-processing, the video object is extracted removing the contours inside the object.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.2
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• pp.116-123
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• 2015

This paper proposed a new formula for predicting acoustic power transmission loss of simple expansion chamber with two internal partitions. Seventeen cases of computational results were performed and the database was constructed for the TL according to the various positions of internal partitions. Using this database, firstly, the formula for the peak values of TL at certain frequencies was developed using the least square estimation. Secondly, the formula for the TL curve could be obtained automatically with the input data of the positions of two internal partitions. The formula of TL developed in this paper showed good agreement with computational results. This formula will be helpful for the positioning of internal partitions to improve TL at target frequencies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8B
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• pp.687-694
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• 2012

In OFDMA-based cellular system, inter-cell interference (ICI) reduces system capacity by aggravating receiving performance of the users located in edge of the cell. Therefore, to mitigate ICI is very important issue in cellular system. To deal with ICI problem, fractional frequency reuse (FFR) is introduced. FFR is an interference management technique. It separates each cell into inner cell and outer cell. Then, it allocates whole system bandwidth to inner cell and different frequency partition to each sector of outer cell. By doing this, outer cell users can ignore interferences from adjacent cells. So, the receiving performance of the cell edge users can be fairly increased. However, using FFR technique has a fatal side effect. In order to use different frequency partition among three sectors of outer cell, they can use only a third of the whole system bandwidth. Then, the reduction of available bandwidth reduces the system throughput directly. To solve this problem, we propose a new FFR method that allocates partially overlapped frequency partition to each sector of outer cell. And then, we suggest a proper overlapping ratio for practical cellular system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2557-2564
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• 2009

In this study, a muffler for the super heavy machinery in the 70 ton class is developed. Developing process relies on experimental and rule of thumb approach. Various muffler internal structures consisting of partition plates, perforated and non-perforated through pipes, and absorbent are tried and compared for the transmission loss performance. Based on the experimental results, the best combination and locations of the internal acoustic components which affects the muffler performance are determined.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.11
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• pp.883-889
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• 2014

Mufflers have been widely used in the exhaust system to reduce the noise. However, installing muffler may deteriorate the efficiency due to the increase of back pressure. Mufflers usually consist of partition plates and perforated holes in a expansion chamber. In this paper, the influences of the location of the partition and hole on the acoustic TL and back pressure were examined. The acoustic TL was predicted using virtual lab commercial software, while the back pressure were predicted using CFX commercial software. The results were used to set up a database for finding their trends. The optimal muffler model in user-interested frequency range could be selected by analyzing this database.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.147-152
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• 2016

One of major issues in machine learning that extracts and acquires knowledge implicit in data is to find an appropriate way of representing it. Knowledge can be represented by a number of structures such as networks, trees, lists, and rules. The differences among these exist not only in their structures but also in effectiveness of the models for their problem solving capability. In this paper, we propose partition utility as a criterion function for clustering that can lead to simplification of the model and thus avoid overfitting problem. In addition, a heuristic is proposed as a way to construct balanced hierarchical models.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.646-680
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• 2000

In this paper, we discuss the design and implementation of a concurrency control manager for a main memory DBMS(MMDBMS). Since an MMDBMS, unlike a disk-based DBMS, performs all of data update or retrieval operations by accessing main memory only, the portion of the cost for concurrency control in the total cost for a data update or retrieval is fairly high. Thus, the development of an efficient concurrency control manager highly accelerates the performance of the entire system. Our concurrency control manager employs the 2-phase locking protocol, and has the following characteristics. First, it adapts the partition, an allocation unit of main memory, as a locking granule, and thus, effectively adjusts the trade-off between the system concurrency and locking cost through the analysis of applications. Second, it enjoys low locking costs by maintaining the lock information directly in the partition itself. Third, it provides the latch as a mechanism for physical consistency of system data. Our latch supports both of the shared and exclusive modes, and maximizes the CPU utilization by combining the Bakery algorithm and Unix semaphore facility. Fourth, for solving the deadlock problem, it periodically examines whether a system is in a deadlock state using lock waiting information. In addition, we discuss various issues arising in development such as mutual exclusion of a transaction table, mutual exclusion of indexes and system catalogs, and realtime application supports.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.89-95
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• 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
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• 2006.02b
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• pp.795-802
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• 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.