• The Journal of the Acoustical Society of Korea
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• v.35 no.4
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• pp.295-302
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• 2016

Underwater acoustic communication channel is often defined as a multipath fading channel since the multipath arrivals from various paths interfere with each other and cause frequency dependent constructive or destructive interference in received signals. Therefore signal-to-noise ratio (SNR) of received signal fluctuates as a function of frequency. In addition, sea surface fluctuation induces frequency dependent time variant signal fading due to coherent component variation of surface bounce path. The frequency shift keying (FSK) system is known to be less sensitive and more robust under these interference and fading, and M-ary frequency shift keying (MFSK) system is adopted to increase a data rate. In this study, a bit error rate (BER) of 4 channels 4FSK system are examined in shallow sea multipath channel. Experimental results show that RS code reduces efficiently the BER of 4FSK system since frequency dependent time-varying fading is characterized to give burst errors. The BER of a different data rate or different source-to-receiver range depends on not only the channel coherent bandwidth but also frequency dependent multipath fading.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.1
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• pp.58-66
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• 2010

In this paper, we have constructed high-resolution topographical map of macro-tidal Malipo beach through integration of terrestrial LiDAR measurement and MBES survey data at inter-tidal zone. To acquire the enough information of inter-tidal zone, we have done terrestrial LiDAR measurement mounted on the roof of vehicle with DGPS through go-stop-scan method at the ebb tide and MBES depth surveying with tide gauge and eye staff measurement for tide correction and MSL calculation at the high tide all together. To integrate two kinds of data, we have unified the vertical coordination standard to Incheon MSL. The mean error of overlapped inter-tidal zone is about 2~6 cm. To verify the accuracy of terrestrial LiDAR, RTK-DGPS measurement have done simultaneously and the difference of Z value RMSE is about 4~7 cm. The resolution of Malipo topographical map is 50 cm and it has constructed to DEM (Digital Elevation Model) based on GIS. Now it has used as an input topography information for the storm-surge inundation prediction models. Also it will be possible to use monitoring of beach process through the long-term periodic measurement and GIS-based 3D spatial analysis calculating the erosion and deposition considering with the artificial beach transition and coastal environmental parameters.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.412-415
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• 2012

A 1-year-old, castrated male Yorkshire terrier (case 1) and a 7-year-old female Poodle (case 2) presented with delayed union fractures. In case 1, the dog had a fractured right distal radius and ulna. In case 2, the dog had a fractured left distal tibia and fibula. A physical examination and radiographs performed in both dogs revealed delayed union fractures with large gaps. The fracture sites were fixed by bone plate and screws. Autogenous cancellous bone graft was applied into the fracture gap. To encourage rapid bone union, we used matrigel containing $20{\mu}g$ of recombinant human bone morphogenetic protein-2 (rhBMP-2) in the fracture site. Radiographs were taken postoperatively to monitor healing. Rapid bone union was noted in both dogs in long-term radiographs. In case 1, the radiographs revealed that the fracture gaps of the radius and ulna were bridged at 2 weeks. Fracture lines were not observed and normal appearance was restored at 20 weeks. In case 2, the radiographs showed that fracture repair had progressed at 11 weeks. The fractures healed faster than expected in these two cases. The results indicate that rhBMP-2 and matrigel may be effective and useful materials to enhance healing of delayed fractures.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.2
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• pp.121-124
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• 2007

Freshwater-adapted maturing chum salmon (Oncorhynchus keta) involuntarily captured by stationary nets in Yang-yang seashore areas were transferred to freshwater in an outdoor raceway tank at Yeongdong Inland Fisheries Research Institute, NFRDI, Yang-yang, Gangwon, Korea and kept over 1 day until the start of the experiments. The freshwater-adapted females were single-injected intraperitoneally with gonadotropin-releasing hormone analogue, (GnRH-a: $70\;{\mu}g/kg$ body weight, BW) alone or combined with a dopamine receptor antagonist, pimozide($700\;{\mu}g/kg$ BW). Although gonadosomatic indices [GSI, (gonad weight/BW)${\times}100$] did not show significant changes in both 2004 and 2005, GSI of GnRH-a-injected fish during the 2005 trial slightly increased on the 5th and 7th days post-injection compared to those of vehicle treated fish. Hepatosomatic indices [HSI, (liver weight/BW)${\times}100$] of fish injected with GnRH-a alone and combined with pimozide decreased significantly on the 7th day post-injection in 2004(P<0.05). In 2005 trials, HSI was significantly reduced in GnRH-a treated fish on the 7th day post-injection (P<0.05). Pimozide-injected fish showed a pattern with increase of GSI and decrease of HSI, without significant differences. Taken together, these results suggest that at least in part hypothalamic hormones and dopamine receptor antagonist may induce sexual maturation in freshwater-adapted maturing chum salmon. It remains to evaluate these preliminary results by further researches.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.772-777
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• 2003

선박이 배출하는 안정수(ballast water)는 외부로부터 유해 생물들이 유입되어 전파해 오는 주요경로로써 해양환경의 매우 중요하고 위험한 일종의 하나이지만, 이에 대한 효과적인 처리방법은 아직까지도 개발되지 못하였다. 그러나 최근 강 전리방전을 이용하여 고 밀집 산소와 물분자를 고농도 수산자유기(OH: hydroxyl radical)로 전리, 활성입자를 발생시켜 신속히 확산시키면 넓은 범위에서 비교적 낮은 농도로 유해성 침입 생물을 잔류물 없이 저렴한 비용으로 살균제나 촉매제의 사용 없이 소멸시켜 처리하는 효과적인 새로운 녹색방법을 제안하였다. 또한, 수산기는 강 산화제로써(산화환원 전위는 2.80 eV), 적조생물을 신속, 효과적으로 사멸시켜 잔유물과 오염물 발생 없이 이상적으로 해양적조현상을 처리할 수 있는 활성물질이다. 고출력 강 전리장치를 활용하면 수산기 활성제의 발생 농도를 Sr104 이상으로 얻을 수 있으므로, 해양적조처리에 요구되는 문턱 값 농도(~l$\times$$10^{-6}$)를 충족시킬 수 있으며, 이 경우 적조생물 소멸처리시간은 불과 10 sec 내외이므로 선박 안정수 처리문제와 함께 적조발생의 난문제를 해양동력학적으로 동시에 해결할 수 있는 효과적인 기술이다. 실험결과로부터 시간당 1 k톤의 활성물질을 발생하는 수산기활성제 제조장치의 경우, 약 4$\times$$10^2$ $\textrm{km}^2$/h의 적조해면을 처리할 수 있으며, 그 비용은 약 US$l,000 정도에 상당하므로, 적조에 따른 경제손실과는 비교될 수 없는 저렴하고 효과적인 방법이다. 활성물질의 생성시간과 가공시간은 불과 수십 $\mu\textrm{s}$ 및 수 sec 에 불과하므로, 1 kton/h 용량의 수산기활성제 제조장치의 환산소비동력은 약 200 kW이고, 장치의 체적은 10~30 ㎥의 공간으로 충분하므로, 소형선박으로 상당면적의 적조피해를 효과적으로 해결할 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1605-1609
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• 2010

CGCM3.1 SRES B1 시나리오의 2D 변수들을 입력값으로 인공신경망 모형을 이용한 스케일 상세화기법으로 강부식(2009)은 소양강댐 유역의 월 누적강수 경향분석을 실시하였다. 원시 GCM 시나리오를 스케일 상세화 시키기 위한 기법의 하나로 인공신경망 모형을 사용할 수 있는데, 이 경우 GCM에서 모의되는 강수플럭스, 해면기압, 지표면 근처에서의 일 평균온도, 지표면 근처에서의 일평균온도, 지표면으로부터 발생하는 잠열플럭스 등과 같은 22개의 변수를 잠재적인 예측인자로 사용하여 신경망을 구성하게 된다. 입력변수세트의 구성은 인공신경망의 계산 효율을 좌우하는 중요한 요소라 할 수 있다. 본 연구에서는 변수의 물리적 특성을 고려하여 순차적인 변수선택을 통한 신경망 입력변수 세트를 구성하고 입력세트 간의 학습성과 비교를 통하여, 최적 입력변수 선정 및 신경망의 학습효과를 높일 수 있는 방법에 대해 연구하였다. 물리적 상관성이 높다고 판단되는 GCM_Prec, huss, ps를 입력변수로 하여 순차적인 케이스를 학습해본 결과 huss와 ps를 입력변수로 하는 케이스에 대해서 적은 오차와 높은 상관성을 보였다, 또한, 신경망의 학습 효과를 높이기 위해 홍수기와 비홍수기로 구분하여 학습한 결과 홍수기와 비홍수기로 구분하여 신경망을 구성하였을 경우가 향상된 모의값을 나타내었다. 기후변화모의자료는 CCCma(Canadian Center for Climate Modeling and Analysis)에서 제공되는 CGCM3.1/T63 20C3M 시나리오를 사용하였으며, 관측값으로는 AWS에서 제공된 일 누적강수를 사용하였다. 인공신경망의 학습기간은 1997년부터 2000년이며, 검증기간은 2001년부터 2004년으로 구성하였다.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.305-313
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• 2019

Men's climactic syndrome, andropause, or testosterone deficit syndrome, is one of the new problems with the health of older men in the age of aging. This phenomenon is a natural phenomenon occurring in men as they age, clinically characterized by a decrease in blood testosterone levels and a marked decrease in physical and mental activity. The purpose of this study was to investigate the effect of hydrothermal extract of Taraxacum coreanum by comparing the levels of nitric oxide (NO) in the cavernosum and the levels of male hormone in the blood. Taraxacum coreanum extract increased NO production in vitro and in vivo in a dose-dependent manner. Levels of dihydrotestosterone and 17-hydroxyysteroid dehydrogenases, as well as levels of neurogenic nitric oxide synthase and cGMP, increased significantly in elderly rats (22 weeks) after 4 weeks of daily intake of Taraxacum coreanum extract. However, prostaglandin $E_2$, testosterone, and sexually-hormone-binding globulin levels were not different among all groups. Furthermore, total sperm and motile sperm counts were also no significant difference. Overall, these results suggest the possibility of Taraxacum coreanum extract as a safe and effective natural substance for enhancing NO, cGMP and free testosterone.

• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.835-845
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• 2023

Traumatic pelvic injuries usually include high-energy crush injuries and are associated with significant morbidity and mortality. Mortality rates range from 6% to 15% and increase to 36%-54% in cases of fractures that result in increased pelvic volume. Therefore, retroperitoneal hemorrhage can spiral and progress to hemorrhagic shock. Pelvic hemorrhage most commonly occurs secondary to disrupted pelvic veins or fractured bones, and 10%-20% of cases involve arterial injuries. Owing to extensive bleeding and limitations of surgery for pelvic hemorrhage, interventional treatment is at the forefront of pelvic hemorrhage management. CT is an accurate indicator of active hemorrhage in patients with pelvic trauma that affects the diagnosis and management, including interventions. Identification of the site of hemorrhage is necessary for focused interventional treatment. The current trend toward a more conservative approach for treatment of pelvic trauma and advances in interventional radiology in the field of pelvic trauma may favor widespread use of interventional treatment for patients with pelvic injuries. In this review, we discuss therapeutic modalities available to the interventional radiologist and common angiographic treatment strategies and techniques.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.171-181
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• 2007

Objective: The present study was aimed at an analytical formulation of the micro-implant related torque as a function of implant size, i.e. the diameter and length, screw size, and the bony resistance at the implant to bone interface. Methods: The resistance at the implant to cancellous bone interface $(S_{can})$ was assumed to be in the range of 1.0-2.5 MPa. Micro-implant model of Absoanchor (Dentos Inc. Daegu, Korea) was used in the course of the analysis. Results: The results showed that the torque was a strong function of diameter, length, and the screw height. As the diameter increased and as the screw size decreased, the torque index decreased. However the strength index was a different function of the implant and bone factors. The whole Absoanchor implant models were within the safe region when the resistance at the implant/cancellous bone $(=S_{can})$ was 1.0 or less. Conclusion: For bone with $S_{can}$ of 1.5 MPa, the cervical diameter should be greater than 1.5 mm if micro-implant models of 12 mm long are to be placed. For $S_{can}$ of 2.0 MPa, micro-implant models of larger cervical diameter than 1.5 mm were found to be safe only if the endosseous length was less than 8 mm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.97-100
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• 2014

To explore the possibility of using pyroligneous acid for environmentally friendly ginseng farming, this study observed samples of ginseng whose shoots were treated with pyroligneous acid sprays beginning in mid June, which is after foliation stage. The spongy tissue structure got thickened from triple layers to quadruple layers with the pyroligneous acid regardless of the concentration. The upper and lower epidermis cell of the leaves as well as the leaf mesopyll cells also became thicker. Compared to the no-treatment group, the overall growth and development of ginseng roots treated with pyroligneous acid were excellent. Accordingly, it is believed that pyroligneous acid can be an environmentally friendly alternative to conventional agro-chemicals applied to ginseng that can be used to facilitate the growth and development of ginseng.