• Progress in Medical Physics
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• v.20 no.2
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• pp.51-61
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• 2009

A Compton camera, which is based on the geometrical interpretation of Compton scattering, is a very promising gamma-ray imaging device considering its several advantages over the conventional gamma-ray imaging devices: high imaging sensitivity, 3-D imaging capability from a fixed position, multi-tracing functionality, and almost no limitation in photon energy. In the present study, a Monte Carlo-based, user-friendly Compton imaging simulator was developed in the form of a graphical user interface (GUI) based on Geant4 and $MATLAB^{TM}$. The simulator was tested against the experimental result of the double-scattering Compton camera, which is under development at Hanyang University in Korea. The imaging resolution of the simulated Compton image well agreed with that of the measured image. The imaging sensitivity of the measured data was 2~3 times higher than that of the simulated data, which is due to the fact that the measured data contains the random coincidence events. The performance of a stacking-structure type Compton camera was evaluated by using the simulator. The result shows that the Compton camera shows its highest performance when it uses 4 layers of scatterer detectors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11A
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• pp.1263-1270
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• 2004

A low-power 64-point FFT/IFFT processor core is designed, which is an essential block in OFDM-based wireless LAM modems. The radix-2/418 DIF (Decimation-ln-Frequency) FFT algorithm is implemented using R2SDF (Radix-2 Single-path Delay Feedback) structure. Some design techniques for low-power implementation are considered from algorithm level to circuit level. Based on the analysis on infernal data flow, some unnecessary switching activities have been eliminated to minimize power dissipation. In circuit level, constant multipliers and complex-number multiplier in data-path are designed using truncation structure to reduce gate counts and power dissipation. The 64-point FFT/IFFT core designed in Verilog-HDL has about 28,100 gates, and timing simulation results using gate-level netlist with extracted SDF data show that it can safely operate up to 50-MHz＠2.5-V, resulting that a 64-point FFT/IFFT can be computed every 1.3-${\mu}\textrm{s}$. The functionality of the core was fully verified by FPGA implementation using various test vectors. The average SQNR of over 50-dB is achieved, and the average power consumption is about 69.3-mW with 50-MHz＠2.5-V.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.425-429
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• 1997

Polyisobutenylsuccinic anhydride(PIBSA), an intermediate for the lubricating oil additive, was prepared by the reaction of polyisobutylene(PIB) with maleic anhydride (MA). The functionality, which indicates the extent of reaction of PIB-a and MA, was determined in the various reaction conditions : fuctionality was 0.98 under the reaction conditions of no solvent for 12 hours at $190^{\circ}C$, 0.21 in benzyl alcohol solvent for 12 hours at $190^{\circ}C$, and 0.03~0.20 with various Lewis acids such as $AlCl_3$, $SnCl_4$, $Et_2AlCl$, and $TiCl_4$. The fuctionality also depended on the structure of PIBs. As ${\alpha}$-olefin content (exo-form) in PIB increased, the fuctionality had a higher value. The structure of PIBSA prepared from PIB and MA was determined with FT IR and $^1H$ NMR spectroscopy. Two strong anhydride IR bands at 1782 and $1855cm^{-1}$ were obserbed and two IR bands at 1639 and $897cm^{-1}$ for unsaturated groups of PIB disappeared. The presence of the anhydride was difficult to find by $^1H$ NMR spectroscopy because the anhydride protons gave relatively small peaks over a 2.0~3.0 range. Polyisobutenylsccinimide (PIBSI), a lublicating oil additive, was prepared by the reaction of PIBSA with diaminoethane.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1665-1673
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• 2013

Recently, the interest and demand on free formed structure providing aesthetic value as well as functionality has been increasing. Formwork has numerous advantages such as high strength, convenience, accuracy and good quality of surface roughness. Nevertheless, it increases construction cost and period to build complex shapes. For these purpose, deposition construction systems such as Contour Crafting and Concrete Printing have been developed with active collaboration between university and industry by applying the rapid prototyping technology to the construction industry in USA and England. Since there has been no related research in Korea, the possibility of spin-off technology and its fusion cannot be expected. In this paper, design elements including mechanical system and control system related to automatic deposition construction system prototype for constructing a free curved structure without mold are described. As for an appropriate material for the system, fiber reinforced mortar was selected by experiments on compressive strength, fluidity, viscosity and setting time. By performing transfer and extrusion experiments, the possibility of the development of deposition construction system was demonstrated. Based on this research results, it is required to keep the automatic deposition construction system improve and extend it into the new application area in construction industry.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.4
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• pp.225-243
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• 2014

As the economic matters are involved, applying the WEC, which is used for controlling waves as well as utilizing the wave energy on existing breakwater, is preferred rather than installing exclusive WEC. This study examines the OWC mounted on a pressurized air chamber floating breakwater regarding the functionality of both breakwater and wave-power generation. In order to verify the performance as a WEC, the velocity of air flow from pressurized air chamber to WEC has to be evaluated properly. Therefore, numerical simulation was implemented based on BEM from linear velocity potential theory as well as Boyle's law with the state equation to analyze pressurized air flow. The validity of the obtained values can be determined by comparing the previous results from numerical analysis and empirically obtained values of different shapes. In the actual numerical analysis, properties of wave deformation around OWC system mounted on fixed type and floating type breakwaters, motions of the structure with air flow velocities are investigated. Since, the wind power generating system can be hybridized on the structure, it is expected to be applied on complex power generation system which generates both wind and wave power energy.

• Journal of Korean Society of Rural Planning
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• v.19 no.3
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• pp.13-24
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• 2013

With the increase of visitors to rural tourism villages, the direct selling at sites is getting vitalized. Accordingly, their display stores is getting more important. Therefore, this study has selected 30 domestic rural tourism villages as study objects for the attitude survey of 200 farming suppliers and the site examination for the designs of those display stores in order to analyze their status and classify the types of necessity. Such operation status as sale item, sale method, method of supply and demand, major customer, sales scale, manager, opening hour, and operation cost were examined, to identity and for design factors the pattern, material quality and color were investigated. For the attitude of farming suppliers, the tactics of sales, the reason for being positive or negative, the functionality and the features of display stores were examined through brainstorming. IBM SPSS Statistics 20 Program was employed for Frequency, which indicated that village chiefs and store managers with the sales scale of 1 to 20 million won are dealing with female customers in their 40's and 50's and that those stores are open at the time of experience or year round without any operation expense. Permanent type and Fixed type were found to be the design factors of the display-case type with the material and the color of wood and orange respectively. The result of investigation analysis of farming suppliers' attitude showed the followings: the need of display stores is quite high, structure type and permanent type have high fitness and from the viewpoint of display-on-table type as a standard moving type was very convenient. The analysis of significant items at the characteristics of those display stores revealed that their locations, quality conservation, sanitation, users' convenience, designs and promotion are very important. The result of status analysis revealed that though there is a correlation among the types of display stores depending on the visiting season of tourists their installing is not desirable. Three types have been analyzed: Type 1 is a structure type only in the villages with continuous visitors, Type 2 a moving-table type only in the villages with temporary visitors and Type 3 is a fixed display-case type.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.78-92
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• 2008

The mutual relationship between fashion and architecture and the similarities in their form and structure have been continuously debated over the decades, considering that both spheres are objects used in human life. Both spheres bring about the creation of three-dimensional space structures that are completed by the human body and material, based on a design targeted for people. The similarities between fashion and architecture in terms of form and structure have been debated by western architecture scholars focusing on the support that holds the garment's shape, the tailoring of a men's suit and also the material. The debate originates from the discussion of F. Th. Vischer, Kritische Gnge, and Gottfried Semper during the nineteenth century on the similarities between crinoline and the form of architecture and also the similarities between sewing and architecture. However, architects always regarded fashion as the inferior creative process that follows architecture in viewing the relationship between fashion and architecture. During the mid to end of the twentieth century, contrary to previous decades, the sense of fashion in architecture stood out, as an issue and a different approach was taken in discussing architecture that incorporates fashion. Accordingly, in the mid 1990's, architecture scholars such as Deborah Fausch and Mark Wigley began to conduct close observation of the mutual relationship between fashion and architecture from a more equal point of view. Notwithstanding, their point of view was still biased towards architectural standards. Commencing the Millennium, fashion has become the primary work of creation which leads style in all spheres, and under these circumstances this point of view has transferred from architecture to fashion when thinking about relationships between these spheres. The discussion on fashion and architecture form fashion's point of view is currently concentrated on the post 1990's phenomenon and illustrates the environment that is related to architecture. In general, the discussion is limited to determining a work of an individual designer as 'being architectural' when explaining the sculptural form of fashion. Therefore, this research aims to renew the discussion on twentieth century fashion design, which was neglected in any studies on observing architecture and fashion. The aim of this research is to classify the architectural paradigm of twentieth century fashion design and to observe the architectural forms of the respective eras. It is necessary to have a close observation of the architectural paradigm in twentieth century fashion design where support tools such as the crinoline was avoided and the form and functionality of the garment itself was emphasized. I will conduct this research by considering the architectural form shown in fashion as a practical three-dimensional creation that exists in space.

• The KIPS Transactions:PartD
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• v.10D no.1
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• pp.1-12
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• 2003

Recently, there have been many indexing schemes for multimedia data such as image, video data. But recent database applications, for example data mining and multimedia database, are required to support multi-user environment. In order for indexing schemes to be useful in multi-user environment, a concurrency control algorithm is required to handle it. So we propose a concurrency control algorithm that can be applied to CBF (cell-based filtering method), which uses the signature of the cell for alleviating the dimensional curse problem. In addition, we extend the SHORE storage system of Wisconsin university in order to handle high-dimensional data. This extended SHORE storage system provides conventional storage manager functions, guarantees the integrity of high-dimensional data and is flexible to the large scale of feature vectors for preventing the usage of large main memory. Finally, we implement the web-based image retrieval system by using the extended SHORE storage system. The key feature of this system is platform-independent access to the high-dimensional data as well as functionality of efficient content-based queries. Lastly. We evaluate an average response time of point query, range query and k-nearest query in terms of the number of threads.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.2
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• pp.70-75
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• 2014

Recently, the demand for high-integrated, low-powered, and high-powered SoC design has been increasing due to the multi-functionality and the miniaturization of digital devices and the high capacity of service informations. With the rapid evolution of the system, the required hardware performances have become diversified, the FPGA system has been increasingly adopted for the rapid verification, and SoC system using the FPGA and the ARM core for control has been growingly chosen. While the AXI bus is used in these kinds of systems in various ways, it is traditionally designed with AXI slave structure. In slave structure, there are problems with the CPU resources because CPU is continually involved in the data transfer and can't be used in other jobs, and with the decreased transmission efficiency because the time not used of AXI bus beomes longer. In this paper, an efficient AXI master interface is proposed to solve this problem. The simulation results show that the proposed system achieves reductions in the consumption clock by an average of 51.99% and in the slice by 31% and that the maximum operating frequency is increased to 107.84MHz by about 140%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.325-330
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• 2000

Alginate obtained from brown algae had various physicochemical and rheological properties and could used as a dietary fiber, However, alginate has not been widely applied to the food industry, since it had high viscosity, high gelling effect conjugated with some mineral, and low solubility. To improve functionality of alginate, partially develymerized alginates, which was water-soluble dietary fiber were obtained by hydrolysis of alginate from the sea tangle, Laminaria japonicus, heated at $121^{\circ}C$. Effects of depolymerization of alginate on the changes of viscosity and average molecular weight, block composition ratio of mannuronate to guluronate (M/G ratio), chemical properties using $PT-IR, ^1H-NMR, and ^(13)C-NMR$ spectrum were investigated. The average molecular weight and viscosity of the alginate were rapidly decreased with the thermal decomposition, and estimated to be 1,307,415 dalton and 284,000 cps, before heating, 728,106 and 3,940.29 cps after 30 min heating, 102,635 and 22.22 cps after 2.5 hrs heating, 51,205 and 12.05 cps after 3 hrs, and 10,049 and 4.28 cps after 6.5 hrs, respectively. The M/G ratio was increased with the heating time, while MM-block did not show any changes and GG-block diminished. The results of $FT-IR, ^1H-NMR and ^(13)C-NMR$ spectrum suggested that changes of molecular structure did not occur by the thermal decomposition.