• Journal of Korean Neurosurgical Society
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• v.49 no.3
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• pp.157-162
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• 2011

Objective : Vasospasm of cerebral vessels remains a major source of morbidity and mortality after an aneurysmal subarachnoid hemorrhage (SAH). The purpose of this study was to evaluate the safety and efficacy of transluminal balloon angioplasty (TBA) for SAH-induced vasospasm. Methods : Eleven patients with an angiographically confirmed significant vasospasm (>50% vessel narrowing and clinical deterioration) were studied. A total of 54 vessel segments with significant vasospasm were treated by TBA. Digital subtraction angiography was used to confirm the presence of vasospasm, and TBA was performed to dilate vasospastic arteries. Medical and angiographic reports were reviewed to determine technical efficacy and for procedural complications. Results : TBA using Hyper-Glide or Hyper-Form balloons (MicroTherapeutics, Irvine, CA) was successfully accomplished in 88.9% vasospastic segments (48 of 54), namely, in the distal internal carotid artery (100%, n=7), the middle cerebral artery (100%), including the M1 (n=10), M2 (n=10), and M3 segments (n=4), in the vertebral artery (100%, n=2), basilar artery (100%, n=1), and in the anterior cerebral artery (ACA), including the A1 (66%), A2 (66%), and A3 segments (100%). Vessel diameters significantly increased after TBA. There were no cases of vessel rupture or thromboembolic complications. GCS at one day after TBA showed an improvement in all patients except one. Conclusion : This study suggests that TBA using Hyper-Glide or Hyper-Form balloons is a safe and effective treatment for subarachnoid hemorrhage-induced cerebral vasospasm.

• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.239-244
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• 2009

Objective : Cerebral vasospasm leading to cerebral ischemic infarction is a major cause of morbidity and mortality in the patients who suffer with aneurysmal subarachnoid hemorrhage. Despite adequate treatment, some patients deteriorate and they develop symptomatic vasospasm. The objective of the present study was to investigate the efficacy and clinical outcome of intraarterial nimodipine infusion on symptomatic vasospasm that is refractory to hemodynamic therapy. Methods : We retrospectively reviewed the procedure reports, the clinical charts and the transcranial doppler, computed tomography and digital subtraction angiography results for the patients who underwent endovascular treatment for symptomatic cerebral vasospasm due to aneurysmal SAH. During the 36 months between Jan. 2005 and Dec. 2007, 19 patients were identified who had undergone a total of 53 procedures. We assessed the difference in the arterial vessel diameter, the blood flow velocity and the clinical outcome before and after these procedures. Results : Vascular dilatation was observed in 42 of 53 procedures. The velocities of the affected vessels before and after procedures were available in 33 of 53 procedures. Twenty-nine procedures exhibited a mean decrease of 84.1 cm/s. We observed clinical improvement and an improved level of consciousness with an improved GCS score after 23 procedures. Conclusion : Based on our results, the use of intraarterial nimodipine is effective and safe in selected cases of vasospasm following aneurysmal SAH. Prospective, randomized studies are needed to confirm these results.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.31-37
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• 1997

This paper describes the design and implementation of 8 bit ALU graphic simulator which helps students who study the structure and operation course of general ALU. ALU of this paper consists of three parts, arithmetic circuit, logic circuit, and shifter. Each of them performs as follows. Arithmetic circuit performs arithmetic operation such as addition, subtraction, 1 increment, 1 decrement, 2's complement, logic circuit performs logic operation such as OR, AND, XOR, NOT, and shifter performs shift operation and transfers the result of circuits of arithmetic, logic to data bus. The instructions which relate to these basic ALU functions was selected from Z80 instructions and ALU circuit was designed with those instructions and this designed ALU circuit was implemented on graphic screen. And all state of this data operation course in ALU was showed by bit and logic gate unit.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.240-245
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• 2012

In this study, we investigated the boosting effects on collagen biosynthesis of $Anthriscus$ $sylvestris$ ethanol extract (ASE) in human dermal fibroblasts. To obtain more effective fraction and subfraction for collagen biosynthesis, standard solvent partition and open column chromatography were performed. The EtOH extract, solvent fractions, and 8 EtOAc subfractions were tested for their collagen synthesis capacity by [$^3H$]Proline-incorporation and ELISA assay. ASE increased 25% of total collagen synthesis and 27% of procollagen biosynthesis. The total collagen biosynthesis was increased by EtOAc fraction and E6 subfraction to 28% and 50% respectively. Type I procollagens were also upregulated by EtOAc fraction and E6 subfraction to 30% and 47%, each. Taken together, our data suggest that potential anti-aging effect of ASE on skin is via increasing collagen biosynthesis and effective subtraction is E6 subfraction of EtOAc fraction.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.163-167
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• 2013

Objective of the study was to compare reflectance spectrum in the blade and the vein parts of cabbage and kale leaves. A total 6 cabbage and kale leaves were taken from a plant factory in Chungnam National University, Korea. Spectra data were collected with a UV/VIS/NIR spectrometer (model: USB2000, Ocean Optics, FL, USA) in the wavelength region of 190 - 1130 nm. Median filter smoothing method was selected to preprocess the obtained spectra data. We computed reflectance difference by subtraction of averaged spectrum from individual spectrum. To estimate correlation at different parts of cabbage and kale leaves, cross - correlation method was used. Differences between cabbage and kale leaves are clearly manifested in the green, red and near - infrared ranges. The percent reflectance of cabbage leaves in the NIR wavelength band was higher than that of kale leaves. Reflectance in the blade part was higher than in the vein part by 18%. Reflectance difference in the different parts of cabbage and kale leaves were clear in all of the wavelength bands. Standard deviation of reflectance difference in the vein part was greater for kale, while the value in the blade part was greater for cabbage leaves. Standard deviation of cross - correlation increased from 0.092 in the first sensor (UV/VIS) and 0.007 in the second sensor (NIR) to 0.099 and 0.015, respectively.

• Journal of Biomedical Engineering Research
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• v.34 no.1
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• pp.24-33
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• 2013

To enhance the speech perception of hearing aid users in noisy environment, most hearing aid devices adopt various beamforming algorithms such as the first-order differential microphone (DM1) and the two-stage directional microphone (DM2) algorithms that maintain sounds from the direction of the interlocutor and reduce the ambient sounds from the other directions. However, these conventional algorithms represent poor directionality ability in low frequency area. Therefore, to enhance the speech perception of hearing aid uses in low frequency range, our group had suggested a fractional delay subtraction and integration (FDSI) algorithm and estimated its theoretical performance using computer simulation in previous article. In this study, we performed a KEMAR test in non-reverberant room that compares the performance of DM1, DM2, broadband beamforming (BBF), and proposed FDSI algorithms using several objective indices such as a signal-to-noise ratio (SNR) improvement, a segmental SNR (seg-SNR) improvement, a perceptual evaluation of speech quality (PESQ), and an Itakura-Saito measure (IS). Experimental results showed that the performance of the FDSI algorithm was -3.26-7.16 dB in SNR improvement, -1.94-5.41 dB in segSNR improvement, 1.49-2.79 in PESQ, and 0.79-3.59 in IS, which demonstrated that the FDSI algorithm showed the highest improvement of SNR and segSNR, and the lowest IS. We believe that the proposed FDSI algorithm has a potential as a beamformer for digital hearing aid devices.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.1
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• pp.9-18
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• 2010

Our country has so large mountain area that the tunnel construction is inevitable and the need of incident detection that provides safe management of tunnels is increasing. In this paper, we suggest a tunnel incident detection system using computer vision techniques, which can detect the incidents in a tunnel and provides the information to the tunnel administrative office in order to help safe tunnel operation. The suggested system enhances the processing speed by using simple processing algorithm such as image subtraction, and ensures the accuracy of the system by focused on the incident detection itself rather than its classification. The system is also cost effective because the video data from 4 cameras can be simultaneously analyzed in a single PC-based system. Our system can be easily extended because the PC-based analyzer can be increased according to the number of cameras in a tunnel. Also our web-based structure is useful to connect the other remotely located tunnel incident systems to obtain interoperability between tunnels. Through the experiments the system has successfully detected the incidents in real time including dropped luggage, stoped car, traffic congestion, man walker or bicycle, smoke or fire, reverse driving, etc.

• Journal of Acupuncture Research
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• v.18 no.2
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• pp.18-26
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• 2001

Purpose : To evaluate the effects of electroacupuncture on regional cerebral blood flow (rCBF) at acupoints suggested by oriental medicine to be related to the treatment of cerebrovascuiar diseases. Materials and Methods : Rest/electroaeupuncture-stimulation Tc-99m ECD brain SPECT using a same-dose subtraction method was performed on 5 normal male volunteers (age range from 27 to 30 years) using electroacupuncture at acupoint, ST 36. In the control study, needle location was chosen on a non-meridian focus 1cm posterior to the right fibular head. All images were spatially normalized and the differences between rest and acupuncture stimulation were statistically analyzed using SPM$^{(R)}$ for Windows$^{(R)}$. Results : Electroacupuncture applied at ST36 increased rCBF in the left hemisphere, that is, the left parietal lobe(angular gyrus), the left temporal lobe, the left inferior frontal lobe around rectus gyrus and the left cerebellar hemisphere, a part of the left inferior frontal lobe. In the control stimulation, no significant rCBF increase was observed. Conclusion : The results demonstrate that electroacupuncture increases rCBF in the contralateral cerebral hemisphere.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.9
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• pp.103-112
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• 1999

In this paper, a speaker-independent isolated world recognition system for a car navigation system is implemented using a general digital signal processor. This paper presents a method combining SNR normalization with RAS as a noise processing method. The semi-continuous hidden markov model is adopted and TMS320C31 is used in implementing the real-time system. Recognition word set is composed of 69 command words for a car navigation system. Experimental results showed that the recognition performance has a maximum of 93.62% in case of a combination of SNR normalization and spectral subtraction, and the performance improvement rate of the system is 3.69%, Presented noise processing method showed good speech recognition performance in 5dB SNR in car environment.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.12
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• pp.82-90
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• 2011

A novel class AB current subtracter(CS) and its application to Norton amplifier(NA) for low-power current-mode signal processing are designed. The CS is composed of a translinear cell, two current mirrors, and two common-emitter(CB) amplifiers. The principle of the current subtraction is that the difference of two input current applied translinear cell get from the current mirror, and then the current amplify through CB amplifier with ${\beta}$ times. The NA is consisted of the CS and wideband voltage buffer. The simulation results show that the CS has current input impedance of $20{\Omega}$, current gain of 50, and current input range of $i_{IN1}$ > $i_{IN2}{\geq}4I_B$. The NA has unit gain frequency of 312 MHz, transresistance of 130 dB, and power dissipation of 4mW at ${\pm}2.5V$ supply voltage.