• 대한의용생체공학회:의공학회지
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• 제36권5호
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• pp.150-154
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• 2015

Long time ultrasound scan can cause a temperature rise in human tissue and affect the physical body. This is closely connected with patients' safety. So many researchers have been studied on this matter with animals such as mammals and experimental rat, because diagnostic ultrasound has been used many types of human organ to find disease. Therefore, this study is tested on bean sprouts to search how far the tissue temperature changes because of the excessive scanning consequence from ultrasound diagnosis and frequent number of ultrasonic scanning and how much affect their growth. The United States and several European countries have restrictions for number of scanning, while South Korea does not have any limitation for using ultrasound diagnosis. Comparison was that how different condition affect its' growing. The testing group is like many pregnancy moms to have 50 minutes in B-mode and color doppler mode by linear, convex and sector probe every day for a week and the other is to scan only once during the testing period. As a result, it was confirmed that there was a significant growing difference on frequent ultrasonic scanning group compared to normal one. So the final conclusion is that there needs to have a significant limitation of ultrasound scan time and a number of inspection when having for diagnostic ultrasound and recommendation like USA and a few European countries.

• Journal of Acupuncture Research
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• 제21권1호
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• pp.33-50
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• 2004

Objective: The aim of this study was to investigate anti-ischemic effect of LR1 HT8 Reduction in Acupuncture Methods: I designed to investigate whether LR1 HT8 Reduction in Acupuncture affects cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP)] in normal rats and to make manifest whether LR1 HT8 Reduction in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was de terminated by video microscope and width analyzer. Results: The results were as follows; 1. LR1 Reduction in Acupuncture was increased rCBF and PAD, but decreased MABP. 2. HT8 Reduction in Acupuncture was significantly increased rCBF, but decreased MABP, and increased PAD. 3. LR1 HT8 Reduction in Acupuncture was significantly increased rCBF, PAD, but decreased MABP after withdrawing of the needle. This results suggest that LR1 HT8 Reduction in Acupuncture increased significantly rCBF by dilating PAD. 4. Pretreatment with indomethacin(1mg/kg, i,v.) was significantly inhibited LR1 HT8 Reduction in Acupuncture induced increase of rCBF and PAD, but increased LR1 HT8 Reduction in Acupuncture induced decrease of MABP after withdrawing of the needle. 5. Pretreatment with methylene blue($10{\mu}g/kg$, i,v.) was decreased LR1 HT8 Reduction in Acupuncture induced increase of rCBF and PAD, but accelerated LR1 HT8 Reduction in Acupuncture induced decrease of MABP. Conclusions: I suggest that LR1 HT8 Reduction in Acupuncture has an anti-ischemic effect through the improvement of cerebral hemodynamics, and the mechanism is mediated by cyclooxygenase.

• Archives of Plastic Surgery
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• 제44권2호
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• pp.109-116
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• 2017

Background The effect of liposuction on the perforators of the lower abdominal wall has been investigated in several studies. There are controversial results in the literature that have primarily demonstrated the number and patency of the perforators. The aim of this study was to determine the effect of liposuction on the perfusion of perforator-based abdominal flaps using a combined laser-Doppler spectrophotometer (O2C, Oxygen to See, LEA Medizintechnik). Methods Nine female patients undergoing classical abdominoplasty were included in the study. Perforators and the perfusion zones of the deep inferior epigastric artery flap were marked on the patient's abdominal wall. Flap perfusion was quantitatively assessed by measuring blood flow, velocity, capillary oxygen saturation, and relative amount of hemoglobin for each zone preoperatively, after tumescent solution infiltration, following elevation of the flap on a single perforator, and after deep and superficial liposuction, respectively. Results The measurements taken after elevation of the flap were not significantly different than measurements taken after the liposuction procedures. Conclusions The liposuction procedure does not significantly alter the perfusion of perforator-based abdominal flaps in the early period. The abdominal tissue discarded in a classic abdominoplasty operation can be raised as a perforator flap and has been demonstrated to be a unique model for clinical research.

• 대한전자공학회논문지SP
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• 제48권4호
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• pp.142-152
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• 2011

일반적으로 기존의 비상 대피용 유도 시스템은 비상등 또는 유도 LED와 같이 시각적인 부분에 의존하고 있다. 실제로 화재인 경우에는 연기 때문에 시야 확보가 힘든 경우가 많다. 본 논문에서는 이런 경우를 대비하여 방향성을 가진 음향을 사용하여 비상 대피 유도 시스템을 설계 및 구현하였다. 이 때 모든 스피커는 편리한 설치를 위해 오디오 직렬 전송 기법을 사용하였다. 대피 경로를 위한 최단 경로 알고리즘은 플로이드 알고리즘을 사용하였다. 오디오 직렬 전송 기법의 단점인 단선에 대한 대책으로 자동 고장 진단 기법을 제안하였다. 시스템 제어와 감시는 PC와 USB 프로토콜 연결을 통하여 이루어진다. 제안한 시스템은 가상의 비상 대피 환경에서 표본 집단의 대피 실험의 효율성을 검증했다. 결론적으로 제안된 시스템은 비상 상황에서 대피율의 증가를 확인하였고 오디오 직렬 전송 기법으로 쉽고 저가의 비용으로 설치 가능하다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권1호
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• pp.178-203
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• 2018

In this paper, authors have been evaluated the Frame Error Rate (FER) performance of IEEE 802.11 a/g/p standard 5 GHz frequency band WLAN over Rayleigh and Rician distributed fading channels in presence of Additive White Gaussian Noise (AWGN). Orthogonal Frequency Division Multiplexing (OFDM) based transceiver is implemented by using real-time signal processing frameworks (IEEE 802.11 Blocks) in GNU Radio Companion (GRC) and Ettus USRP N200 is used to process the symbol over the wireless radio channel. The FER is calculated for each sub-carrier conventional modulation schemes used by OFDM such as BPSK, QPSK, 16, 64-QAM with different punctuated coding rates. More precise SNR is computed by modifying the SNR calculation process of YANS and NIST error rate model to estimate more accurate FER. Here, real-time signal constellations, OFDM signal spectrums etc. are also observed to find the effect of multipath propagation of signals through flat and frequency selective fading channels. To reduce the error rate due to the multipath fading effect and Doppler shifting, channel estimation (CE) and equalization techniques such as Least Square (LS) and training based adaptive Least Mean Square (LMS) algorithm are applied in the receiver. The simulation work is practically verified at GRC by turning into a pair of Software Define Radio (SDR) as a simultaneous transceiver.

• 동의생리병리학회지
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• 제17권5호
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• pp.1194-1201
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• 2003

Jaeumgenby-tang(JGT) have been used in oriental medicine for many centries as a therapeutic agent of vertigo caused by deficiency of qi(氣) and blood(血). Effect of Aurantii Fructus(AF) take off the phlegm by promoting the circulation of qi, Gastrodae Rhizoma(GR) has effects treating for headarch, vertigo by calming the liver and suppressing hyperactivity of the liver-yang (陽). I investigated whether injection of JGT adding AFㆍGR extract(JTG) affects cerebral hemodynamics [regional cerebral blood f1ow(rCBF), pial arterial diameter(PAD) in cerebral ischemia rats by MCA occlusion method, and I designed to make manifest whether JTG is mediated by adrenergic β-receptor, cyclooxygenase or guanylate cyclase. The changes of rCBF was determinated by laser-doppler flowmetry(LDF), and the changes of PAD was determinated by video microscope and width analyzer. The results were as follows in cerebral ischemic rats; The changes of rCBF and PAD were increased stabilizly by treatment with JTG(10 ㎎/kg, i.v.) during the period of cerebral reperfusion, and pretreatment with propranolol and indomethacin were increased JTG induced increase of rCBF and PAD during the period of cerebral reperfusion. Pretreatment methylene blue was decreased JTG induced increase of rCBF and PAD during the period of cerebral reperfusion. In conclusion, JTG causes a diverse response of rCBF and PAD, and action of JTG is mediated by adrenergic β-receptor and cyclooxygenase. I suggest that JTG has an anti-ischemic effect through the improvement of crebral hemodynamics.

• The Journal of Advanced Prosthodontics
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• 제2권1호
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• pp.7-13
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• 2010

Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS. In vitro, the human platelets were activated with application of shear stress, $20\;{\mu}g/ml$ collagen, 2 mM $CaCl_2$ and 10U thrombin/$1\;{\times}\;10^9$ platelets. Level of vascular endothelial growth factor (VEGF) and platelet microparticle (PMP) in the activated platelets were checked. In the animal study, human angiogenic factors-enriched PRP was tested in 28 athymic rat's cranial critical bone defects with $\beta$-TCP. Angiogenesis and osteogenesis were evaluated by laser Doppler perfusion imaging, histology, dual energy X-ray densinometry, and micro-computed tomography. RESULTS. In vitro, this human angiogenic factors-enriched PRP resulted in better cellular proliferation and osteogenic differentiation. In vivo, increasing angiogenic potential of the PRP showed significantly higher blood perfusion around the defect and enhanced new bone formation around acellular bone graft material. CONCLUSION. Angiogenic factor-enriched PRP leads to faster and more extensive new bone formation in the critical size bone defect. The results implicate that rapid angiogenesis in the initial healing period by PRP could be supposed as a way to overcome short term effect of the rapid angiogenesis.

• 대한약침학회지
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• 제16권4호
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• pp.30-35
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• 2013

Objectives: This study was designed to investigate the effects of Calculus Bovis-Fel Uris-Moschus pharmacopuncture (BUM) on the regional cerebral blood flow (rCBF) and the mean arterial blood pressure (MABP) in normal and cerebral ischemic rats and to investigate a possible pathway involved in the effects of BUM. Methods: The changes in the rCBF and the MABP following BUM into Fengfu (GV16) were determined by using a laser-Doppler flow meter and a pressure transducer, respectively. Results: BUM significantly increased the rCBF and decreased the MABP in normal rats in a dose-dependent manner. The effect on the rCBF was significantly inhibited by pretreatment with methylene blue (0.01 mg/kg, intraperitoneal), an inhibitor of guanylate cyclase, but was not affected by pretreatment with indomethacin (1 mg/kg, intraperitoneal), an inhibitor of cyclooxygenase. The BUM-induced decrease of the MABP was changed neither by methylene blue nor by indomethacin pretreatment. In the cerebral ischemic rats, the rCBF was stably increased upon cerebral reperfusion in the BUM group in contrast to the rapid and marked increase in the control group. Conclusion: This study demonstrated that BUM into Fengbu (GV16) increased the rCBF in a dose-dependent manner in the normal state; furthermore, it improved the stability of the rCBF in the ischemic state upon reperfusion. Also, the effects of BUM on the rCBF were attenuated by inhibition of guanylate cyclase, suggesting that the effects involved the guanylate cyclase pathway.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1370-1378
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• 2008

In the system necessary for safety such as the train control system, to make train control information be sent correctly is very important. In the case of the system such as RF-CBTC(Radio Frequency-Communication Based Train Control), sometimes failure in correctness of train controlling information may happen because the information is sent throughout wireless transmission between on-board system of a train and wayside transmitter, and then, it is exposed to noises. Of RF-channel interference, there are various forms. Under the environment of mobile telecommunications, adjacent-channel interference and Co-channel interference are in trouble, and under the environment of the wireless LAN, inter-symbol interference is in trouble. Also, the system of the cellular CDMA mobile telecommunication is affected on the RF-channel interference such as Doppler effect, multi-cell interference, and other users' intervention. In this paper, we analyzed the effect of the train control information related to fading, intervention and other noises made in the underground interval and explained the transmission characteristics numerically. Furthermore, we calculated the mean of the error terms by increasing users in the system of the cellular CDMA. As the method for decrease the error term of sent information, we represented the way adjusting the arrangement of antennas, and we did the model related to the system of RF-CBTC in which the location of an antenna is calculated with really measured value of the transmission characteristics and the way confirming reliability of the wireless transmission.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.1-10
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• 2022

This study discusses the effect of using ²³²Th instead of ²³⁸U on the neutronic characteristics and the main operating parameters of the pressurized water reactor (PWR). MCNPX version 2.7 was used to compare the neutronic characteristics of UO₂ with (Th, ²³⁵U)O₂ and (Th, ²³³U) O₂. Firstly, the infinity multiplication factor (K_inf), thermal neutron flux, and power distribution have been studied for the investigated fuel types. Secondly, the effect of Gd₂O₃ and Er₂O₃ on the K_inf and on the radial thermal neutron flux and thermal power has been investigated to distinguish which of them is more suitable than the other in reactivity management. Thirdly, to illustrate the effectiveness of ²³²Th in decreasing the inventory of both the actinides and non-actinides, the concentration of plutonium (Pu) isotopes and minor actinides (MAs) has been simulated with the fuel burnup. Besides, due to their large thermal neutron absorption cross-section, the concentrations of ¹³⁵Xe, ¹⁴⁹Sm, and ¹⁵¹Sm with the fuel burnup have been investigated. Finally, the main safety parameters such as the reactivity worth of the control rods (ρ_CR), the effective delayed neutron fraction β_eff, and the Doppler reactivity coefficient (DRC) were calculated to determine to which extent these fuel types achieve the acceptable limits.