• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.512-519
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• 2023

Noise pollution poses significant challenges to human well-being and marine ecosystems. It is primarily caused by the flow around ships and marine installations, emphasizing the need for accurate noise evaluation of flow noise to ensure environmental safety. Existing flow noise analysis methods for underwater environments typically use a hybrid method combining computational fluid dynamics and Ffowcs Williams-Hawkings acoustic analogy. However, this approach has limitations, neglecting near-field effects such as reflection, scattering, and diffraction of sound waves. In this study, an alternative using direct method flow noise analysis via the lattice Boltzmann method (LBM) is incorporated. The LBM provides a more accurate representation of the underwater structural boundaries and acoustic wave effects. Despite challenges in underwater environments due to numerical instabilities, a novel DM-TS LBM collision operator has been developed for stable implementations for hydroacoustic applications. This expands the LBM's applicability to underwater structures. Validation through flow noise analysis in pipe orifice demonstrates the feasibility of near-field analysis, with experimental comparisons confirming the method's reliability in identifying main pressure peaks from flow noise. This supports the viability of near-field flow noise analysis using the LBM.

• Journal of Veterinary Clinics
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• v.28 no.5
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• pp.497-505
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• 2011

Natural orifice transluminal endoscopic surgery is a newly emerging technique recently, with its many potential advantages in clinical practice. Cholecystectomy by Hybrid NOTES in this work, performed with single working channel endoscope in conjunction with a laparoscopic grasping forceps in dogs, is a "bridge" between laparoscopic procedure and pure NOTES. Three different approaches for cholecystectomy were carried out; transgastric, transcolonic and transvaginal. In all three approaches, abdominal opening was made by a 5 mm trocar, followed by making pneumoperitoneum of 4 mmHg with $CO_2$ insufflator. Transgastric cholecystectomy, single working channel endoscope was advanced to the peritoneal cavity through gastric incision in antral region made by endoscopic needle knife. Endoscope was retroflexed to visualize the gall bladder. Transcolonic access, incision for endoscopic entry was done at right ventral wall of descending colon, 15 cm inside from the anus. Incision in transvaginal access was made at right-ventral region, just caudal to the caudal tubercle. With the simple traction by the laparoscopic grasping forceps, good visualization of surgical field was obtained in all three groups. Cystic duct and artery were ligated with endoclips; for complete gall bladder dissection from liver, L-knife was used. Closure of incision sites were done in transgastric and transcolonic cholecystectomy by endoclips, not in transvaginal approach.

• Korean Journal of Materials Research
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• v.24 no.10
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• pp.543-549
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• 2014

A zinc oxide (ZnO) hybrid structure was successfully fabricated on a glass substrate by metal organic chemical vapor deposition (MOCVD). In-situ growth of a multi-dimensional ZnO hybrid structure was achieved by adjusting the growth temperature to determine the morphologies of either film or nanorods without any catalysts such as Au, Cu, Co, or Sn. The ZnO hybrid structure was composed of one-dimensional (1D) nanorods grown continuously on the two-dimensional (2D) ZnO film. The ZnO film of 2D mode was grown at a relatively low temperature, whereas the ZnO nanorods of 1D mode were grown at a higher temperature. The change of the morphologies of these materials led to improvements of the electrical and optical properties. The ZnO hybrid structure was characterized using various analytical tools. Scanning electron microscopy (SEM) was used to determine the surface morphology of the nanorods, which had grown well on the thin film. The structural characteristics of the polycrystalline ZnO hybrid grown on amorphous glass substrate were investigated by X-ray diffraction (XRD). Hall-effect measurement and a four-point probe were used to characterize the electrical properties. The hybrid structure was shown to be very effective at improving the electrical and the optical properties, decreasing the sheet resistance and the reflectance, and increasing the transmittance via refractive index (RI) engineering. The ZnO hybrid structure grown by MOCVD is very promising for opto-electronic devices as Photoconductive UV Detectors, anti-reflection coatings (ARC), and transparent conductive oxides (TCO).

• The Korean Journal of Applied Statistics
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• v.31 no.4
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• pp.447-461
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• 2018

Domestic film industry sales are increasing every year. Theaters are the primary sales channels for movies and the number of audiences using the theater affects additional selling rights. Therefore, the number of audiences using the theater is an important factor directly linked to movie industry sales. In this paper we consider a hybrid model that combines a multiple linear regression model and the Bass model to predict the audience numbers for a specific day. By combining the two models, the predictive value of the regression analysis was corrected to that of the Bass model. In the analysis, three films with different release dates were used. All subset regression method is used to generate all possible combinations and 5-fold cross validation to estimate the model 5 times. In this case, the predicted value is obtained from the model with the smallest root mean square error and then combined with the predicted value of the Bass model to obtain the final predicted value. With the existence of past data, it was confirmed that the weight of the Bass model increases and the compensation is added to the predicted value.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.2
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• pp.19-24
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• 1991

This paper propose a new taegeuk shaped directional couper and verify the possibility of high power division rate in those directional coupler through the experiments. We took the taegeuk shaped structure in those proposed directional coupler to utilize a $3\lambda/4$ section of hybrid ring directional coupler actively, and calculated the branch admittances, which satisfied the condition of perfect matching and isolation in the center frequency, by even odd mode analyzing methodes. On the result, we knew that it can be realized a much higher power division rate than reported result in same circuit area within the producible resistance limit in the microstrip line, made the taegeuk shaped directional couplers with 0, 8, 16 dB power split ratio in the 10 GHz frequency using CGP - 502 plate, and confirmed the validity of theory through the experiments.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.367-380
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• 2015

This paper proposes a hybrid rendering method which combines pre-computed global illumination results and interactive local illumination techniques and thus could interactively produce photo-realistic visual effects for mobile entertainment applications. The proposed method uses the programmable shading capability of OpenGL, a de facto standard for computer graphics library so that it can be deployed in a real-world development environment. Also, it increases the rendering time by a negligible amount compared to normal rendering time since the pre-computed results are used as operands of plain arithmetic operations. Therefore it is expected to be applicable in practice for mobiles games which require real-time responsiveness to users.

• The Inventors News
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• no.53
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• pp.1-16
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• 2006

'여성기업지원에 관한 법률' 개정 한 목소리/발행인 칼럼/'제4회 여성발명경진대회' 수준 높아졌다/심사착수 예정시기 직접 통지 서비스 실시/특허청.한국기계연구원, 업무협약체결/낙도어린이들에게 꿈과 희망 심어주는 초청 행사 가져/특허청 팀장 선발 방식 변화 통한 팀제 강화/디자인 권리화 지원사업 실시한다/'DMB 특허품과 지재권전략 세미나'/'2006 독일 국제발명품 전시회' 회원 4명 수상/고성능 하이브리드 보호복, 출원 증가/'이달의 기능 한국인' 박순복 씨 선정/모방상표, 더 이상 등록 받을 수 없다/국내제약업계, 유사브랜드 너무많아/'2006 여성 재활용 발명경진대회' 개최/순수 한방재료로 만든 헤어 클리닉 화제/발명자에게 편리한 특허제도 마련/차로 마시는 '허브 추출물'로 살충제 만들어/종이컵에도 웰빙 바람이 불고 있다/특허공보 통해 '나의 발명' 확인가능/지역특산품도 지리적 표시로 보호 받는다/한미약품,'비만치료제 특허권 분재' 연승/국내특허, 해외에서 신속하게 심사 처리/'스판덱스 특허소송'에서 일본업체 패소/아모레, 다국적 화장품회사 로레알에 승소/제7차 한국.유럽 특허청장 회담 개최/고부가가치 창출하는 단백질 의약품 개발 필요/한방 진료에도 변화의 새바람 분다/에너지 절감'기능성 유리' 출원 급증/역사 속의 발명품/하루 10분 발명교실/특허Q&A/세상을 밝히는 여성들의 발명 아이디어/'특허넷' 정부기관 최초 CMMI 레벨4인증 획득/'해외지재권 보호 가이드북' 제작배포하다/아이디어 착상 및 발명 기법/고정관념을 깨트려 블루오션을 장악하라/에반스의 증기제분기/50년 후엔 동물과도 대화할 수 있다/첩보용 도구 전달 '발명팀' 실제 존재/중소기업 위한'2006 특허유통 페스티벌' 개최/출원료.심사청구료 반환제도 도입, 시행/'지재권 e-러닝 콘텐츠' 전 세계특허청 교육 자료로 활용/대한변리사회, 미 특허법 세미나 개최/한국여성발명협회 회원사 발명품 가이드

• The Journal of the Acoustical Society of Korea
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• v.13 no.4
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• pp.60-68
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• 1994

In this paper we propose a new Hybrid learning rule applied to multilayer feedforward neural networks, which is constructed by combining Hebbian learning rule that is a good feature extractor and Back-Propagation(BP) learning rule that is an excellent classifier. Unlike the BP rule used in multi-layer perceptron(MLP), the proposed Hybrid learning rule is used for uptate of all connection weights except for output connection weigths becase the Hebbian learning in output layer does not guarantee learning convergence. To evaluate the performance, the proposed hybrid rule is applied to classifier problems in two dimensional space and shows better performance than the one applied only by the BP rule. In terms of learning speed the proposed rule converges faster than the conventional BP. For example, the learning of the proposed Hybrid can be done in 2/10 of the iterations that are required for BP, while the recognition rate of the proposed Hybrid is improved by about $0.778\%$ at the peak.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.793-800
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• 2015

This study is to analyze correlation between Daniel Libeskind's architecture works and the effects as a series of music works be learning in youth and opera "Aron and Mose". The results showed that First, Libeskind created convergence of invisible line by borrowing the composition of freely flowed scales in score from his architecture. Second, he composed geometrical shapes of contrapuntal reiteration based on double tune in music structure, in other words forms of polyphonic proportion. and he expressed the geometrically, freely line rhythm by planning composition of multidimensional spaces, "Hybrid", planning the contrast of material, form by results of Intertextually combination between Architecture and Music. Third, he tried to express the pain, fear, anxiety, etc. of the past spatially, and constructed "the spaces of absence" on his works through inspiration from Arnold Sch$\ddot{o}$nberg's works.

• Journal of the Korean Society for Nondestructive Testing
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• v.16 no.1
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• pp.1-9
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• 1996

Many signal-processing techniques have been found to be useful in ultrasonic and nondestructive evaluation. Among the most popular techniques are signal averaging, spatial compounding, matched filters and homomorphic processing. One of the significant new process is split-spectrum processing(SSP), which can be equally useful in signal-to-noise ratio(SNR) improvement and grain characterization in several specimens. The purpose of this paper is to explore the utility of SSP in ultrasonic NDE. A wide variety of engineering problems are reviewed, and suggestions for implementation of the technique are provided. SSP uses the frequency-dependent response of the interfering coherent noise produced by unresolvable scatters in the resolution range cell of a transducer. It is implemented by splitting the frequency spectrum of the received signal by using gaussian bandpass filter. The theoretical basis for the potential of SSP for grain characterization in SUS 304 material is discussed, and some experimental evidence for the feasibility of the approach is presented. Results of SNR enhancement in signals obtained from real four samples of SUS 304. The influence of various processing parameters on the performance of the processing technique is also discussed. The minimization algorithm, which provides an excellent SNR enhancement when used either in conjunction with other SSP algorithms like polarity-check or by itself, is also presented.