• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.715-724
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• 2000

This Paper presents 3-D subband filter banks which are effective for progressive and lossless compression of volumetric images. For such a purpose, ORT(Overlapping Rounding Transform), applied so far to 1-D losslesssubband filter banks, is now used to implement two types of 3-D lossless subband filter banks: separable andnon-separable types. Separable fiter banks are implemented form applying 1-D lossless filter banks consecutively.Non-separable later banks are developed by expanding the 1-D ORT into 3-D one. In particular, the proposed ORT based 3-D non-separable filter banks generalizes the 3-D HINT(Hierarchical INTerpolation) algorithm.Through the experiment comparisons on various volumetric medical images, we prove that the proposedseparablefnon-separable filter banks perform better, in terms of compression ratio (first order entropy), than theother lossless compression techniques such as block based transform and conventional 3-D HINT.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.5
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• pp.66-74
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• 2002

OFDM(Orthogonal Frequency Division Multiplexing)is a one of the nst promising digital modulation techniques adapted for Digital audio broadcasting or Digital TV since it is very robust against multipath fading channels. From 1997, since the OFDM technique was considered as the physical layer standard for the high data rate wireless LAN systems in the 5㎓ band, related studies have been studied actively. The key element to implement high data rate wireless LAN system using OFDM technique are IFFT and FFT modules. In this paper, new IFFT and FFT module are designed and implemented using current cut circuit based on the matrix-rounding process for the low-power consumptive operation and high-speed data processing. In addition to, we certify the available operation of the rounded IFFT/FFT module in the AWGN channel by using the BER performance simulation of IEEE 802.11TGa based OFDM modem with rounded IFFT/FFT module.

• Korean Journal of Cognitive Science
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• v.15 no.1
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• pp.1-11
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• 2004

The aim of this study is to reveal the order and the age of mastery of phonemic contrast in vowel sounds of Korean. For this purpose, we made an observation of the correspondences between the sounds produced by children of 12-35 months and the target sounds produced by adults. The provisional order and the age of contrast acquisition shown from the results of this study are as follows. First, the differential production of vowels by the feature relating to the body of the tongue precedes the differential production of vowels by the feature relating to the lip rounding. Second, as for the differential production of vowels by the feature relating to the body of the tongue, the contrast between the low vowels and the others is accomplished first, and the contrast between the high and low vowels and the contrast between the front and the back vowels are established around the age of 24 months. Third, as for the differential production of vowels by the feature relating to the lip rounding, the contrast between the rounded and the unrounded vowel is not accomplished until 36 months. Finally, we observed, prior to the completion of the differential production of phonemes, children use a specific phoneme excessively. This passing phrase could be interpreted as a result of over-application of a distinctive feature in the course of acquisition of it.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.408-413
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• 1996

A self-diagnostic, air-damped, piezoresitive, cantilever-beam microaccelerometer has been designed, fabricated and tested for applications to automotive electronic airbag systems. A skew-symmetric proof-mass has been designed for self-diagnostic capability and zero transverse sensitivity. Two kinds of multi-step anisotropic etching processes are developed for beam thickness control and fillet-rounding formation, UV-curing paste has been used for sillicon-to-glass bounding. The resonant frequency of 2.07kHz has been measured from the fabricated devices. The sensitivity of 195 $\mu{V}$/g is obtained with a nonlinearity of 4% over $\pm$50g ranges. Flat amplitude response and frequency-proportional phase response have been obserbed, It is shown that the design and fabricaiton methods developed in the present study yield a simple, practical and effective mean for improving the performance, reliability as well as the reproducibility of the accelerometers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.10
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• pp.1433-1443
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• 1993

DCT(Discrete Cosine Transform) / IDCT(Inverse DCT) is widely used in various image compression and decompression systems as well as in DSP(Digital Signal Processing) applications. Since DCT/ IDCT is one of the most complicated part of the compression system, the performance of the system can be greatly enchanced by improving the speed of DCT/IDCT operation. In this thesis, we designed a DCT/IDCT core processor using module generator technique. By utilizing the partial sum and DA(Distributed Arithmetic) techniques, the DCT/ IDCT core processor is designed within small area. It is also designed to perform the IDCT(Inverse DCT) operation with little additional circuitry. The pipeline structure of the core processor enables the high performance, and the high accuracy of the DCT/IDCT operation is obtained by having fewer rounding stages. The proposed design is independent of design rules, and the number of the input bits and the accuracy of the internal calculation coa be easily adjusted due to the module generator technique. The accuracy of the processor satisfies the specifications in CCITT recommendation H, 261.

• Korea Journal of Hospital Management
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• v.7 no.2
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• pp.37-51
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• 2002

It has been 2 years since the implementation of the separation of prescription and drug dispensing policy. This study analyzes the effects of the policy on the job contents and personnel structure of hospital pharmacy. The main purposes of the analysis are to determine if the policy has causes the increase of professional activities of pharmacists in hospital and to investigate whether the hospital pharmacy is equipped with enough manpower to provide high quality pharmaceutical service as intended by the policy. The level of professionality of pharmacists' activities is measured by the number of activities of direct involvement in inpatient care such as participation in patient rounding, medication consultation, the number of hospital committee the pharmacists involved and the number of continuous education pharmacists took. The adequacy of personnel structure to provide high quality pharmaceutical care is measured by the level of compliance to the governmental standard of hospital pharmacy personnel. In order to collect the data, surveys were performed for two periods: year 1999 (before the implementation of the policy) and year 2001 (after the implementation of the policy). The results show that the pharmacists' participation in inpatient rounding decreased and that the inpatient medication history management activities, operation of ward pharmacy, participation in hospital committee increased. In personnel structure, the average number of pharmacist per hospital decreased and the number of prescription processing per pharmacist increased. Based on the results this study concludes that the professional activities of hospital pharmacists has increased a little and there were structural changes in hospital pharmacy service activities to increase the professionalism in providing care. However, the pharmacy departments were understaffed hampering the strive to increase the provision of professional pharmaceutical service in hospitals.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.5
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• pp.65-73
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• 2002

In this paper, we propose and verify an implementation method for a single-chip 2048 complex point FFT/IFFT in terms of sequential data processing. For the sequential processing of 2048 complex data, buffers to store the input data are necessary. Therefore, DRAM-like pipelined commutator architecture is used as a buffer. The proposed structure brings about the 60% chip size reduction compared with conventional approach by using this design method. The 16-point FFT is a basic building block of the entire FFT chip, and the 2048-point FFT consists of the cascaded blocks with five stages of radix-4 and one stage of radix-2. Since each stage requires rounding of the resulting bits while maintaining the proper S/N ratio, the convergent block floating point (CBFP) algorithm is used for the effective internal bit rounding and their method contributed to a single chip design of digital audio broadcasting system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.285-299
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• 1993

The objective of the present study is to analyze material flow in the metal forming processes by using computer simulation and experiment with model material, plasticine. A UBET program is developed to analyze the bulk flow behaviour of various metal forming problems. The elemental strain-hardening effect is considered in an incremental manner and the element system is automatically regenerated at every deforming step in the program. The material flow behavior in closed-die forging process with rib-web type cavity are analyzed by UBET and elastic-plastic finite element method, and verified by experiments with plasticine. There were good agreements between simulation and experiment. The effect of corner rounding on material flow behavior is investigated in the analysis of backward extrusion with square die. Flat punch indentation process is simulated by UBET, and the results are compared with that of elastic-plastic finite element method.

• Journal of Educational Research in Mathematics
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• v.16 no.4
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• pp.273-295
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• 2006

It is the purpose of this study to help computational estimation study to settle down in effective teaching method through analysis how students are understanding computational estimation and what occurs using computational estimation in actual life problem situations. I set 3 cases to accomplish these purposes. (1) How students are understanding computational estimation? (2) How students' computational estimation ability is in applying actual life problem situation? (3) What is students' different attitudes in an actual life problem situation before studying computational estimation and after? To accomplish tile purpose, I chose 6 third grade students and taught 'Computational estimation using actual life problem situation' and analyzed students computational estimation processing. Then I arranged the computational estimation processing in an actual life problem situation and differences between the before and tile after. As a result, I obtained the followings. (1) Need of estimation: Every students could recognize the need of estimation with experiencing an actual life problem situation. (2) Choosing the order of decimals: Students could choose appropriate order of decimals according to an actual life problem situations. (3) Using strategy: They usually use rounding strategy and quite often use special number and compatible number strategy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.11-17
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• 2010

Multi-standard, multi-band, multi-service system to ensure a flexible interface between the SDR (Software Defined Radio) technology for the implementation of the Stability and Low-Power, Low-Calcualrion DDC (Digital Down Conversion) technology is essential. DDC technology consists of a digital channel filter. This is a typical digital filter because of the limited fisheries are vulnerable to overflow and rounding errors are drawbacks. In this paper, we overcome this disadvantage, we propose the structure of the DDC. The way WDF (Wave Digital Filter) Structural rounding error due to the structural resistance to noise. Therefore, This is the useful structure when the filter coefficients's word length is short. In addition, since IIR filters based on FIR filters based on the amount of computation is reduced because fewer than filter's tap. The proposed structure is used in DDC that CIC (Cascaded Integrator Comb) filter, WDF, IFOP (Interpolated Fourth-Order Polynomials) were analyzed with respect to, the results were confirmed by computer simulation.