• The Korean Journal of Pain
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• v.24 no.4
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• pp.199-204
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• 2011

Background: Although many clinicians know about the reducing effects of the pulsed and low-dose modes for fluoroscopic radiation when performing interventional procedures, few studies have quantified the reduction of radiation-absorbed doses (RADs). The aim of this study is to compare how much the RADs from a fluoroscopy are reduced according to the C-arm fluoroscopic modes used. Methods: We measured the RADs in the C-arm fluoroscopic modes including 'conventional mode', 'pulsed mode', 'low-dose mode', and 'pulsed + low-dose mode'. Clinical imaging conditions were simulated using a lead apron instead of a patient. According to each mode, one experimenter radiographed the lead apron, which was on the table, consecutively 5 times on the AP views. We regarded this as one set and a total of 10 sets were done according to each mode. Cumulative exposure time, RADs, peak X-ray energy, and current, which were viewed on the monitor, were recorded. Results: Pulsed, low-dose, and pulsed + low-dose modes showed significantly decreased RADs by 32%, 57%, and 83% compared to the conventional mode. The mean cumulative exposure time was significantly lower in the pulsed and pulsed + low-dose modes than in the conventional mode. All modes had pretty much the same peak X-ray energy. The mean current was significantly lower in the low-dose and pulsed + low-dose modes than in the conventional mode. Conclusions: The use of the pulsed and low-dose modes together significantly reduced the RADs compared to the conventional mode. Therefore, the proper use of the fluoroscopy and its C-arm modes will reduce the radiation exposure of patients and clinicians.

• The KIPS Transactions:PartC
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• v.19C no.3
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• pp.179-184
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• 2012

Due to the absence of an alternative algorithm SHA-2, NIST (National Institute of Standards and Technology) is proceeding to development project of SHA-3. NIST announced five candidates of the final round at the end of 2010. Side-channel attack scenarios of five candidates for SHA-3 final round have been proposed. In this paper, we prove the possibility of the analysis against 32-bit modular addition by 8-bit blocks from our experiment on ARM chip board with a register size of 32-bit. In total we required 9700 power traces to successfully recover the 128-bit secret key for the attack against.

• Journal of Korean Neurosurgical Society
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• v.50 no.2
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• pp.139-142
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• 2011

Vertebral involvement of fibrous dysplasia (FD) is rare, especially in the cervical spine. Moreover, cervical FD presenting as a pathologic fracture in older patients is extremely rare. We report a case of symptomatic cervical FD associated with pathologic fracture in a 63-year-old man. The patient presented with progressive weakness of the left arm and pain in the shoulder and arm. Radiologic studies revealed a collapsed and typical 'ground glass' radiolucency of C4. Multiple lytic lesions involved the odontoid process of C2 and the body, left pedicle, and posterior elements of C4. Combined anterior and posterior decompression and reconstruction were performed. Post-operatively, the histopathologic examination confirmed FD. On the post-operative follow-up examination, the neurologic deficits had completely resolved.

• Journal of Korean Neurosurgical Society
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• v.51 no.2
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• pp.120-123
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• 2012

Objective : Percutaneous vertebroplasty (PVP) is usually carried out under three-dimensional (2D) fluoroscopic guidance. However, operative complications or bone cement distribution might be difficult to assess on the basis of only 2D radiographic projection images. We evaluated the feasibility of performing an intraoperative and postoperative examination in patients undergoing PVP by using three-dimensional (3D) reconstructive C-arm. Methods : Standard PVP procedures were performed on 14 consecutive patients by using a Siremobil Iso-$C^{3D}$ and a multidetector computed tomography machine. Post-processing of acquired volumetric datasets included multiplanar reconstruction (MPR) and surface shaded display (SSD). We analyzed intraoperative and immediate postoperative evaluation of the needle trajectory and bone cement distribution. Results : The male : female ratio was 2 : 12; mean age of patients, 70 (range, 77-54) years; and mean T score, -3.4. The mean operation time was 52.14 min, but the time required to perform and post-process the rotational acquisitions was 7.76 min. The detection of bone cement distribution and leakage after PVP by using MPR and SSD was possible in all patients. However, detection of the safe trajectory for needle insertion was not possible. Conclusion : 3D rotational image acquisition can enable intra- or post-procedural assessment of vertebroplasty procedures for the detection of bone cement distribution and leakage. However, it is difficult to assess the safe trajectory for needle insertion.

• Journal of IKEEE
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• v.24 no.4
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• pp.1172-1175
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• 2020

Automotive ECU integrates CPU core, IVN controller, memory interface, sensor interface, I/O interface, and so on. Current automotive ECUs are often developed with proprietary processor architectures. However, demends for standard processors such as ARM and RISC-V increase rapidly for saftware compatibility in autonomous vehicles and connected cars. In this paper, an automotive ECU is designed for parking assist system based on RISC-V with open instruction set architecture. It includes 32b RISC-V CPU core, IVN controllers such as CAN and LIN, memory interfaces such as ROM and SRAM, and I/O interfaces such as SPI, UART, and I2C. Fabricated in 65nm CMOS technology, its operating frequency, area, and gate count are 50MHz, 0.37㎟, and 55,310 gates, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.10 s.352
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• pp.68-73
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• 2006

This, paper proposes a cosimulation methodology that results in an efficient SoC design as well as fast verification by integrating HDL, SystemC, and algorithm-level abstraction using the design tools Active-HDL and Matlab's Simulink. To demonstrate the proposed design methodology, we implemented the design technique on a serial connection multi-channel speaker system. We have demonstrated the proposed cosimulation method utilizing an ARM processor based SoC Master board with the AMBA bus interface and a Xilinx Vertex4 FPGA. The proposed method has the advantage of simultaneous simulation verification of both software and hardware parts in high levels of abstraction mixed with some performance critical parts in more concrete RTL codes. This allows relatively fast and easy design of a speaker connection system which typically requires significant amount of data processing for verification.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.575-582
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• 2008

In this paper we described the process and the results of real-time implementation of G.729.1 wideband speech codec which is standardized in SG15 of ITU-T. To apply the codec on ARM926EJ-S(R) processor core. we transformed some parts of the codec C program including basic operations and arithmetic functions into assembly language to operate the codec in real-time. G.729.1 is the standard wideband speech codec of ITU-T having variable bit rates of $8{\sim}32kbps$ and inputs quantized 16 bits PCM signal per sample at the rate of 8kHz or 16kHz sampling. This codec is interoperable with the G.729 and G.729A and the bandwidth extended wideband($50{\sim}7,000Hz$) version of existing narrowband($300{\sim}3,400Hz$) codec to enhance voice quality. The implemented G.729.1 wideband speech codec has the complexity of 31.2 MCPS for encoder and 22.8 MCPS for decoder and the execution time of the codec takes 11.5ms total on the target with 6.75ms and 4.76ms respectively. Also this codec was tested bit by bit exactly against all set of test vectors provided by ITU-T and passed all the test vectors. Besides the codec operated well on the Internet phone in real-time.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.132-143
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• 1993

Aminomethyl polystyrene resins were prepared either from chloromethyl-resin(Merrifield resin) or from direct amidoalkylation of polystyrene resin. Two kinds of aminomethlyl resin were lengthened with spacer arms via sequential coupling of five ${\varepsilon}$-aminocaproic acids(ACA) respectively. In case of the resin prepared from the Merrifield resin, the amounts of free amino group of the resin were reduced by 25~30% after each coupling of ACA. But the one from direct amidoalkylation showed 3~5% loss after each coupling of ACA. 4-Nitroso-5-aminopyrazole resin was made by reacting ACA spacer arm resin, which was made from direct amidoalkylated resin, with 5-phenyl-7-methylpyrazole [4,3-c][1,2,4]oxadiazin-3-one. Several polymeric active esters of N-blocked amino acids were prepared from the 4-nitroso-5-aminopyrazole bound resins. In anchoring step of the amino acid derivatives on the resin, no substantial effect of bulkiness was found. 4-Nitroso-5-aminopyrazole bound active ester resins were found to be very reactive in N-acylation, The resulting peptides were obtained with 90~95% yield and characterized by NMR and other physical methods.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.43-51
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• 2008

In this paper, we are implemented low-power structure for Inter prediction, Intra prediction, Deblocking filter, Transform and Quantization blocks in H.264/AVC Encoder. The proposed Inter/Intra prediction blocks are shown 60.2% cell area reduction by adder reduction through Distributed Arithmetic, 44.3% add operation reduction using MUX for hardware share in Deblocking filter block. Furthermore we applied CSD and CSS process to reduce the cell area instead of multipliers that take a lot of area. The FPGA(Field Programmable Gate Array) and ARM Process based H.264/AVC encoder is implemented using proposed low power IPs. The proposed structure Platforms are implemented to interlock with FPGA and ARM processors. H.264/AVC Encoder implementation using Platforms shows that proposed low-power IPs can use H.264/AVC Encoder SoC effectively.

• Journal of Korea Foundry Society
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• v.27 no.2
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• pp.77-82
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• 2007

The effects of thermal gradient and solidification rate on the dendrite arm spacing and carbide morphology were investigated in directionally solidified Ni-base superalloy, CM 247LC. Thermal gradient was controlled by changing the position of the cold chamber and the furnace set temperature. The interface morphology changed from the planar to dendritic as increasing solidification rate. It was found that the dendrite spacing decreased as increasing the thermal gradient as well as the solidification rate. Also, as increasing solidification rate, carbide morphology changed from blocky shape to script and spotty shapes.