• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.987-990
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• 1998

An optical adder for a modified signed-digit(MSD) number system using joint spatial encoding method is proposed. In order to minimize the numbers of symbolic substitution rules, nine input patterns were divided into five groups of the same addition results. For recognizing the input reference patterns, masks and reference patterns without any other spatial operations are used. This adder is implemented by smaller system in size than a conventional adder.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.84-88
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• 1999

Recently, the necessity of accessing spatial data from remote computer via network has been increased as distributed spatial data have been increased due to their size and cost. Many methods have been used in recent years for transferring spatial data, such as socket, CORBA, HTTP, RPC, FTP, etc. In this paper, we propose spatial clearinghouse components to access distributed spatial data sources via CORBA and Internet. The spatial clearinghouse components are defined as OLE/COM components that enable users to access spatial data that meet their requests from remote computer. For reusability, we design the spatial clearinghouse with UML and implement it as a set of components. In order to enhance interoperability among different platforms in distributed computing environment, we adopt international standards and open architecture such as CORBA, HTTB, and OpenGIS Simple Features Specifications. There are two kinds of spatial clearinghouse: CORBA-based spatial clearinghouse and Internet-based spatial clearinghouse. The CORBA-based spatial clearinghouse supports COM-CORBA bridge to access spatial data from remote data providers that satisfy the OpenGIS Simple Features Specification for OLE/COM using COM and CORBA interfaces. The Internet-based spatial clearinghouse provides Web-service components to access spatial data from remote data providers using Web-browser.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.353-369
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• 2000

We systematized an stratified spatial sample design(SSSD) that uses the adequate stratification criteria such as the shapeness or the dispersion of an interesting region in a spatial population. And we proposed an adaptive searching estimation method in the SSSD to estimate the area of region of interest in two-dimensional surfaces. When wc adopt the proposed adaptive searching estimation method in SSSD, the observing sample size is more decreased than a classical sample design that all the designed sample size is observed. Nevertheless it has been shown that we can produce the moderate result but the efficiency is a slight reduced.

• 지반과기술
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• v.3 no.3
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• pp.15-22
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• 2006

The optimum blasting pattern to excavate a quarry efficiently and economically can be determined based on the minimum production cost, which is generally estimated according to rock fragmentation. Therefore, it is a critical problem to predict fragment size distribution of blasted rocks over an entire quarry. By comparing various prediction models, it can be ascertained that the result obtained from Kuz-Ram model relatively coincides with that of field measurements. Kuz-Ram model uses the concept of rock factor to signify conditions of rock mass such as block size, rock jointing, strength and others. For the evaluation of total production cost, it is imperative to estimate 3-D spatial distribution of rock factor for the entire quarry. In this study, a sequential indicator simulation technique is adopted for estimation of spatial distribution of rock factor due to its higher reproducibility of spatial variability and distribution models than Kriging methods. Further, this can reduce the uncertainty of predictor using distribution information of sample data. The entire quarry is classified into three types of rock mass and optimum blasting pattern is proposed for each type based on 3-D spatial distribution of rock factor. In addition, plane maps of rock factor distribution for each ground level are provided to estimate production costs for each process and to make a plan for an optimum blasting pattern.

• Journal of the Korean Institute of Rural Architecture
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• v.15 no.1
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• pp.89-96
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• 2013

This study aims to clarify the transformation of urban spatial structure around old castle in cheong-ju city. The urban spatial structure is composed with road system, block division, and lot system with original cadastral map in 1913 and 2011 GIS. Transformation of road system is classified into control of road line, construction and extension of road. Construction of arterial road was divided into Nam-juro and Mang-sunro with 2 blocks and lot system was destoyed. Transformation of block has not been developed except 4 blocks. The 4 blocks were divided into east-west or north-south direction and became 8 blocks. Transformation of lot system is classified into maintained, subdivided, and destroyed lots in shape and size of lots. Maintained lots were found in large lot in size for public office and park. Subdivided lots were mainly represented with the existing main road, an active alleys, and so on. Destroyed lots by road construction and extension were showed in Nam-juro. Although all these transformations are used to enhance urban spatial structure. The old systems have remained around old castle in cheong-ju city.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.7
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• pp.701-710
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• 2008

Including a TV set and a monitor, personal audio system is raising a great interest. In this study, we applied a method to make a good bright zone around the user and dark zone to other region by maximizing the ratio of sound energy between the bright and dark zone. It has been well known as acoustic contrast control. We have attempted to use a line loudspeaker array system to localize the sound in our listening zone. It depends on the size of the zone and array parameters, for example, array size, loudspeaker unit spacing, wave length of sound. We have considered these parameters as spatial variables and studied the effects. And we have found that each spatial variable has its own characteristic and shows very different effect. Genetic algorithms are introduced to find out the optimum value of spatial variables. As a result, we can improve the result of the acoustic contrast control by optimum value of spatial variables.

• Korean Institute of Interior Design Journal
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• no.2
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• pp.17-21
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• 1994

The purpose of this study was to compare the spatial structures for household activities according to the house size. multi-Dimentional Scaling analysis was done, using questinonaire data from 349 middle income housewives living in apartment in the area of Captital region. This was an extended article of previous one. In case of house whose size was less than 20 Pyung, washing cloth and bathing behavior took place in the same place whereas in other house size, bathing behavior was incoperated into various behaviors usually shown in the bedroom. The ideal structure in the house of 20 Pyung's showed home office space closer to the bedroom area whereas in others it appeared independently.

• Journal of Radiation Industry
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• v.11 no.3
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• pp.167-171
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• 2017

This study examined the effectiveness degree of a protective apron that is taken not to be exposed to the first ray or scattered rays, for X-ray of thick subject like lateral lumbar, and the results are as follows; First, spatial dose by scattered rays is shielded by 3 mmPb protective apron, 86.8% at a distance of 50 cm, 92.7% at 100 cm, and 95.6% at 200 cm, when minimizing the field size, while 89% at a distance of 50 cm, 92.3% at 100 cm, and 95.2% at 200 cm, when maximizing the field size. Second, 1st exposure dose is shielded by 3 mmPb protective apron, 93.7% at a distance of 50 cm, 94.4% at 100 cm, and 93.6% at 200 cm, when minimizing the field size, while 93.7% at a distance of 50 cm, 93.6% at 100 cm, and 94.2% at 200 cm, when maximizing the field size.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.10
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• pp.1862-1878
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• 2011

With the advances in wireless communication technology and the advent of smartphones, research on location-based services (LBSs) is being actively carried out. In particular, several spatial index methods have been proposed to provide efficient LBSs. However, finding an optimal indexing method that balances query performance and index size remains a challenge in the case of wireless environments that have limited channel bandwidths and device resources (computational power, memory, and battery power). Thus, mechanisms that make existing spatial indexing techniques more efficient and highly applicable in resource-limited environments should be studied. Bitmap-based Spatial Indexing (BSI) has been designed to support LBSs, especially in wireless broadcast environments. However, the access latency in BSI is extremely large because of the large size of the bitmap, and this may lead to increases in the search time. In this paper, we introduce a Selective Bitmap-based Spatial Indexing (SBSI) technique. Then, we propose an Adaptive Bitmap-based Spatial Indexing (ABSI) to improve the tuning time in the proposed SBSI scheme. The ABSI is applied to the distribution of geographical objects in a grid by using the Hilbert curve (HC). With the information in the ABSI, grid cells that have no objects placed, (i.e., 0-bit information in the spatial bitmap index) are not tuned during a search. This leads to an improvement in the tuning time on the client side. We have carried out a performance evaluation and demonstrated that our SBSI and ABSI techniques outperform the existing bitmap-based DSI (B DSI) technique.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.13-20
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• 2009

Recently there is growing interest in LBS requiring real-time services and the spatial main memory DBMS for efficient Telematics services. In order to optimize existing disk-based spatial indexes of the spatial main memory DBMS in the main memory, spatial index structures have been proposed, which minimize failures in cache access by reducing the entry size. However, because the reduction of entry size requires compression based on the MBR of the parent node or the removal of redundant MBR, the cost of MBR reconstruction increases in index update and the efficiency of search is lowered in index search. Thus, to reduce the cost of MBR reconstruction, this paper proposed the RSMB (relative-sized MBR)compression technique, which applies the base point of compression differently in case of broad distribution and narrow distribution. In case of broad distribution, compression is made based on the left-bottom point of the extended MBR of the parent node, and in case of narrow distribution, the whole MBR is divided into cells of the same size and compression is made based on the left-bottom point of each cell. In addition, MBR was compressed using a relative coordinate and size to reduce the cost of search in index search. Lastly, we evaluated the performance of the proposed RSMBR compression technique using real data, and proved its superiority.