• Journal of Korean Neurosurgical Society
• /
• v.56 no.1
• /
• pp.16-20
• /
• 2014

Objective : Two-dimensional fluoroscopy-based computerized navigation for the placement of pedicle screws offers the advantage of using stored patient-specific imaging data in providing real-time guidance during screw placement. The study aimed to describe the accuracy and reliability of a fluoroscopy-based navigation system for pedicle screw insertion. Methods : A total of 477 pedicle screws were inserted in the lower back of 96 consecutive patients between October 2007 and June 2012 using fluoroscopy-based computer-assisted surgery. The accuracy of screw placement was evaluated using a sophisticated computed tomography protocol. Results : Of the 477 pedicle screws, 461 (96.7%) were judged to be inserted correctly. Frank screw misplacement [16 screws (3.3%)] was observed in 15 patients. Of these, 8 were classified as minimally misplaced (${\leq}2mm$); 3, as moderately misplaced (2.1-4 mm); and 5, as severely misplaced (>4 mm). No complications, including nerve root injury, cerebrospinal fluid leakage, or internal organ injury, were observed in any of the patients. Conclusion : The accuracy of pedicle screw placement using a fluoroscopy-based computer navigation system was observed to be superior to that obtained with conventional techniques.

• Proceedings of the KIEE Conference
• /
• 2002.07d
• /
• pp.2353-2356
• /
• 2002

The increase of vehicles stagnations leads to the increasing attention to the way customers pay and a large number of projects on electronic cash system. Tranport system is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Recently many research on a system which provides contact in order to protect driver's vehicle passage have been carried out. And some potential problems from that system are being reviewed by electronic cash system. In this papers, we suggest RF protocol developing technology using the concept of electronic cash. ATM electronic cash developing is consist of component of pre-developed coin throw, integration of component using its, and production of more requirement-satisfactory ITS solution. Result increase 15$\sim$40% pre-type vehicles stagnations. Especially, we expect this proposed concept would be well adapted to our national environments.

• 한국태양에너지학회:학술대회논문집
• /
• 2011.04a
• /
• pp.256-262
• /
• 2011

Environmental pollution by Using of a fossil fuel, a reckless and growth-oriented development since the Industrial Revolution has caused global change of environment. An issue largest among this is a climate change. A global mean temperature since 19th century has climbed up $0.4{\sim}0.8^{\circ}C$. After The Kyoto Protocol regarding a greenhouse gas reduction goal took effect, be situations that decrease of greenhouse gas was acutely required. Interest of utilization of the new & renewable energy is increasing every day. This study shows that at first divided a country to nine range by natural geography, and second executed Meteorological data analysis of recent 30 years considering level of significance by nine range. The results of this study are that in heating load calculation of building, periodic temperature data management is required because facility capacity and cost are affected greatly by outdoor temperature, and temperature by climate range needs consideration of pertinent area. Lastly, ground temperature was assumed of the weather in region, the ground and soil.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.7B
• /
• pp.694-702
• /
• 2009

Geographical routing protocol, where nodes only need local information exchange to make routing decisions, is a very efficient routing scheme for wireless sensor networks in scalability. However, pure geographical routing does not take account of wireless link condition. If wireless link condition is not considered, when the routing table is updated, the nodes with bad link conditions are updated in the routing table and can be chosen as the next hop. This brings out the retransmissions because of received packet's errors. Also, because of these retransmissions, additional power is consumed. In this paper, we propose geographical routing scheme considering wireless link condition, where reliable data transmission is made and the consumed energy is minimized.

• Phonetics and Speech Sciences
• /
• v.9 no.2
• /
• pp.125-135
• /
• 2017

The current study examines PCC (percentage of correct consonant), speech intelligibility, and oral motor function between the group of typically developing children and the group of children with Down's syndrome. To 15 children with Down's syndrome (mean CA: 9;7) and 15 typically developing children on receptive language age, the following tests were administered: K-WPPSI (2001), Picture Vocabulary Test (Kim et al., 1995), Oral and Speech Motor Control Protocol for total oral functional score (Robbins et al., 1987), DDK and Assessment of Phonology and Articulation for Children (APAC, Kim et al., 2007) for PCC and speech intelligibility. Pearson correlation coefficients were computed for the total oral functional score, PCC and DDK of each group. The statistical analysis showed that there is no significant difference in total functional score and DDK when IQ was controlled. There was a significant correlation between total oral functional score and PCC in the Down's syndrome group and a significant correlation between total oral functional score and intelligibility in the Down's syndrome group whether IQ was controlled or not. The findings suggest that both cognitive ability and overall oral motor function need to be considered for the intervention to enhance PCC or speech intelligibility of children with Down's syndrome.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2001.10a
• /
• pp.671-674
• /
• 2001

Q+P Esto는 정보가전용 RTOS인 Q+P를 위한 원격 개발 환경이다. 타겟에이전트는 타겟에서 실행되면서 호스트에 있는 디버거와 원격쉘, 그리고 자원모니터 같은 Q+P Esto 도구들이 원격 개발을 하는데 필요한 기본적인 기능들을 제공한다. 본 논문은 GNU gdb 5.0에 있는 gdbserver를 이용하여 타겟에서 실행 중인 응용 프로세스를 감시 및 제어하는 구조를 제안한다. 디버깅을 위하여 정지점(breakpoint)에 걸린 응용 프로세스를 continue 시켰을 때 응용 프로세스가 무한 루프에 빠지더라도 타겟에이전트는 다른 도구의 요청을 계속 처리할 수 있다. 응용 프로세스를 제어하는 자세한 메커니즘은 gdbserver가 담당한다. 따라서, 타겟에이전트는 단지 gdb remote protocol만 사용하여 gdbserver와 통신하면 되므로 구현이 용이하다.

• Proceedings of the KOSOMBE Conference
• /
• v.1996 no.05
• /
• pp.179-183
• /
• 1996

Most of the conventional electrocardiogaphies fail to detect signals other than P-QRS-T due to the limited SNR and bandwidth. High-resolution electrocardiography (HRECG) provides better SNR and wider bandwidth for the detection of micro-potentials with higher frequency components such as ventricual late potentials(LP). In this paper, we developed a HRECG using uncorrected XYZ lead. The overall gain of the amplifier is 4000 and the bandwidth is $0.5{\sim}300Hz$ without using 60Hz notch filter. Three 16-bit AH converters sample X, Y, and Z signals simultaneously with a sampling frequency of 2000Hz. Sampled data are transmitted to PC via a DMA-controlled serial communication channel using RS-485 and HDLC protocol. The noise level of the developed HRECG is less than $5{\mu}V_{rms,\;RTI}$. In order to further reduce the noise level, signal averaging technique is implemented utilizing template matching method. The SNR of the developed HRECG is high enough for the detection of LP.

• Progress in Superconductivity and Cryogenics
• /
• v.23 no.4
• /
• pp.44-48
• /
• 2021

In order to obtain ultra-high resolution MRI images, research and development of 11 T or higher superconducting magnets have been actively conducted in the world, recently. The high-temperature superconductor (HTS), first discovered in 1986, was very limited in industrial application until mid-2010, despite its high critical current characteristics in the high magnetic field compared to the low-temperature superconductor. This is because HTS magnets were unable to operate stably due to the thermal damage when a quench occurred. With the introduction of no-insulation (NI) HTS magnet winding technology that does not burn electrically, it could be expected that the HTS magnets are dramatically reduced in weight, volume, and cost. In this paper, a 6 T-class NI HTS magnet for basic characteristic analysis was designed, and a distributed equivalent circuit model of the NI coils was configured to analyze the charging current characteristics caused by excitation current, and the charge delay phenomenon and loss were predicted through the development of a simulation model. Additionally, the critical current of the NI HTS magnets was estimated, considering the magnetic field, its angle and temperature with a given current. The loss due to charging delay characteristics was analyzed and the result was shown. It is meaningful to obtain detailed operation technology to secure a stable operation protocol for a 6T NI HTS magnet which is actually manufactured.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.1788-1791
• /
• 2010

위치 측정 기술의 발달로 인해 다양한 서비스들이 개발 되어 현대 사회에 제공되고 있다. 이러한 서비스들 중 GPS는 현재 우리 사회에 깊숙이 녹아 들어와 핸드폰, 내비게이션, 배송처리, 차량 위치 파악, 긴급구조서비스, 항공 및 선박 항법장치, DSLR 등 다양한 분야에서 활용되고 있다. GPS는 위성신호를 수신하여 위치를 파악하기 때문에 위성신호를 수신할 때 공간상의 제약이 있고, 매우 민감하게 방해요소에 의해 간섭을 받을 수 있다. 차량이 충돌위험 발생시 GPS가 방해요소로 인해 수신되지 않으면 충돌회피를 위한 시스템이 제대로 작동하지 못할 우려가 있다. 본 논문에서는 GPS가 수신율이 떨어지는 터널, 고가도로, 지하주차장과 같은 장소에서의 WLAN을 기반으로 한 위치측정 기술을 이용하여 차량의 충돌회피를 방지하기 위한 프로토콜을 제안한다.

• Journal of Life Science
• /
• v.17 no.2 s.82
• /
• pp.198-203
• /
• 2007

DNA transfection is a powerful tool for studying gene functions. The $Ca^{2+}$-phosphate precipitation remains one of the most popular and cost-effective transfection techniques. Mature neurons are more resistant to transfection than young ones and most other cell types, and easy to die if microenvironment changes. Here, we report a transfection protocol for mature neurons. The critical modifications are inclusion of glial cells in culture and careful control of $Ca^{2+}$-phosphate precipitation under microscope. Cerebral glial cells were grown until ${\sim}70-80%$ confluence in DMEM/10% horse serum, which was thereafter replaced with serum-free Neurobasal/Ara-C, and 319 hippocampal neurons were plated onto the glial layer Formation of fine $DNA/Ca^{2+}$-phosphate precipitates was induced using Clontech $CalPhos^{TM}$ Mammalian Transfection Kit, and the size ($0.5-1\;{\mu}m$ in diameter) and density(about 10 particles/$100\;{\mu}m^2$) were carefully controlled by the time of incubation in the medium. This modified protocol can be reliably applied for transfection of mature neurons that are maintained longer than two weeks in vitro, resulting in 10-15 healthy transfected neurons per a well of 24-well plates. The efficacy of the protocol was verified by punctate expression of $pEGFP-CaMKII{\alpha}$, a synaptic protein, and diffuse expression of pDsRed2. Our protocol provides a reliable method for transfection of mature neurons in vitro.