• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제15권12호
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• pp.923-927
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• 2009

최근 디지털 음반 시장의 발전으로 인해 음악 검색 및 추천에 대한 수요가 증가하고 있는데 이러한 서비스를 수행하는 음악 기반 응용 시스템의 성능 향상을 위해서는 일반적인 음악의 형태인 다음(Polyphonic) 음악에서 멜로디를 추출하는 과정이 필수적이다. 본 논문에서는 다음의 복잡도가 높고 넓은 음역을 가지는 음악을 만들 수 있는 피아노 솔로 음악에서 멜로디를 추출하는 방법을 제안한다. 본 연구는 피아노 음악을 음악의 특성에 따라 세 가지 유형으로 분류해서 유형별로 멜로디를 추출하는 방법을 살펴본다. 제안한 방법에 따라 구현된 시스템을 이용해서 성능을 측정한 결과 다양한 피아노 솔로 음악에 적용 가능함을 확인했다.

• 설비공학논문집
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• 제17권6호
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• pp.514-520
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• 2005

Surface heat transfer of a fully developed turbulent air flow in a $45^{\circ}$ inclined ribbed square duct with two and four heating walls was experimentally investigated, at which the experimental works were peformed for Reynolds numbers ranging from 7,600 to 26,000. The pitch-to-rib height ratio, p/e, was kept at 8 and rib-height-to-channel hydraulic diameter ratio, $e/D_h$ was kept at 0.0667. The channel length-to-hydraulic diameter ratio, $L/D_h$ was 60. The heat transfer coefficient values were decreased with the increase in the number of heat-ing walls. Results of this investigation could be used in various applications of internal channel turbulent flow involving roughened walls.

• 방송공학회논문지
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• 제26권7호
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• pp.838-843
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• 2021

This paper presents an algorithm for effective retrieval of score information to an input score image. The originality of the proposed algorithm is that it is designed to be robust to recognition errors by an OMR (Optical Music Recognition), while existing methods such as pitch histogram requires error induced OMR result be corrected before retrieval process. This approach helps people to retrieve score without training on music score for error correction. OMR takes a score image as input, recognizes musical symbols, and produces structural symbolic notation of the score as output, for example, in MusicXML format. Among the musical symbols on a score, it is observed that filled noteheads are rarely detected with errors with its simple black filled round shape for OMR processing. Barlines that separate measures also strong to OMR errors with its long uniform length vertical line characteristic. The proposed algorithm consists of a descriptor for a score and a similarity measure between a query score and a reference score. The descriptor is based on note-count, the number of filled noteheads in a measure. Each part of a score is represented by a sequence of note-count numbers. The descriptor is an n-gram sequence of the note-count sequence. Simulation results show that the proposed algorithm works successfully to a certain degree in score image-based retrieval for an erroneous OMR output.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.478-492
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• 2021

In this study, hull dimensions of an FPSO were optimized to maximize its operability at Brazil field. In contrast with the previous works which have used simplified models to evaluate some indicators related to stability and hydrodynamic performances of FPSOs for its own optimal design, we developed a generic hull and compartment modeler and sophisticated stability and hydrodynamic calculation modules. With the aid of the developed tools, the hull optimization was performed with initial dimensions of an FPSO originally designed for west Africa field. The optimization results indicated the relative importance of hydrodynamic performances compared with stability performances for the FPSO hull dimensioning by showing that there were 3 active constraints related to them, which were the natural periods of heave and roll and the maximum pitch angle under 1-year return period waves at full load condition. To the author's knowledge, this study is the first attempt to combine altogether the hull and compartment modeling and full set of stability and hydrodynamic calculations precisely to optimize an FPSO's hull dimensions within 30 min. Also, it is worthwhile to mention that the developed methods are generic enough to be applied to all types of ship-shaped offshore platforms.

• Current Optics and Photonics
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• 제7권5호
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• pp.485-495
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• 2023

The pixel size in high-resolution complementary metal-oxide-semiconductor (CMOS) image sensors continues to shrink due to chip size limitations. However, the pixel pitch's miniaturization causes deterioration of optical performance. As one solution, a quad color filter (CF) array with pixel binning has been developed to enhance sensitivity. For high sensitivity, the microlens structure also needs to be optimized as the CF arrays change. In this paper, the covered microlens, which consist of four microlenses covered by one large microlens, are proposed for the quad CF array in the backside illumination pixel structure. To evaluate the optical performance, the suggested microlens structure was simulated from 0.5 ㎛ to 1.0 ㎛ pixels at the center and edge of the sensors. Moreover, all pixel structures were compared with and without in-pixel deep trench isolation (DTI), which works to distribute incident light uniformly into each photodiode. The suggested structure was evaluated with an optical simulation using the finite-difference time-domain method for numerical analysis of the optical characteristics. Compared to the conventional microlens, the suggested microlens show 29.1% and 33.9% maximum enhancement of sensitivity at the center and edge of the sensor, respectively. Therefore, the covered microlens demonstrated the highly sensitive image sensor with a quad CF array.

• 복식
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• 제41권
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• pp.185-206
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• 1998

The purpose of this study was to improve productivity for maximum effects with the present equipments and staff. This study compared and analyzed the mea-sured time by using stop watch method and MTM, which was the new measuring method. The flow and results of this study were as follows: 1. This study investigated the theoretical background the efficiency for production management, and the way of productivity improvement through documentary research. 2. Setting up the standard flow on the experi-mental company production, making out a process chart and measuring the actual working hour. 3. The study measured the allowance time applying work sampling. 4. Each process of the movement analysis was filmed by video to use basic data. 5. MTM analysis was taken by choosing 10 processes from front bodice according to the basic movement of MTM. Through the results, this study exclude unneccesary movements and suggest a method for working ways. 6. Using the actual working hour measured by a stop watch calculated the pitch time and presumed the amount of daily productivity. 7. The result of the work sampling came out as 38% of allowance rate. It was 13% higher than the standard amount of woman's jacket allowance rate, which was 25%. The most influencing factor was work discussion. That was because there were commuication problem of the work way between the operator and leader. More adequate use of flow table and level passing table was needed. There were the problems that inappropriate places and sizes made the distance of movements longer and often needed more adjustment of works and surroundings. To prevent breakdowns equipments check ups were necessary before works. 8. The results of MTM analysis were as follow : the time was reduced 40% than the actual measured time by a stop watch. This was because the leveling of the operator was included in the real calculation. Also, leveling was included in MTM analysis and all the conditions were standarized. Therefore MTM method was a scientidic measuring way of establishing the standard time. The presented method of this study, suggested an ideal method eliminating unneccesary motions, and presented standardization of works. Improvement of working methods, work condition and simplifying motions in each 10 processes reduced the working time from total 656 seconds to 301 seconds. 9. The way and time of working was linked together in the MTM analysis methods. Thus data from MTM help suggest not only establishing standard time but also establishing stan-dard work. Plus it includes various ability for improvements of working ways. So it is an objective method which can be widely used in other work studies. 10. The function of a time study is to determine the amount of work produced with a given method. The work rate is used to establish the cost of labor. The wage of worker must be calculated per unit time which is deter-mined before the time study is made. This study tried to introduce the incentive rule for deciding wages according to the standard time by MTM method.

• 만화애니메이션 연구
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• 통권33호
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• pp.173-202
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• 2013

본 연구 기획개발(development) 단계에 대한 이론적 검토를 통해 한국의 애니메이션 산업 구조에 가장 적합한 제작과정의 초기 단계를 정립시키고자 한다. 그 중요성에 비해 잘 알려지지 않은 기획개발 단계는 애니메이션 제작을 하기 전 어떤 작품을 만들 것인가를 구상하는 단계로서 가장 초기 단계이자 동시에 가장 기초적인 부분이다. 이 단계는 작품의 주제가 결정되고, 제작을 위해 필요한 기초 준비가 이루어지는 단계로서, 애니메이션 제작 과정 중 프리 프로덕션(pre-production) 단계 이전에 설정된다. 기획개발 단계의 역할을 살펴보면 크게 두 가지 유목으로 정리될 수 있다. 하나는 프로젝트 콘텐츠 부분으로서 스토리와 직접적으로 연관되는 것들이다. 구체화된 아이디어를 가지고 제작에 필요한 지원을 받기 위한 활동에 들어갈 준비를 해야 하기 때문에 매우 중요하다. 다른 하나는 프로젝트 제작지원 혹은 사업 부분으로서 재정, 인사, 일정에 관한 부분이다. 이와 같은 업무를 수행해낼 역할과 권한을 가진 자는 바로 제작자(producer) 혹은 총괄제작자(executive producer)이다. 이들의 참여는 기획개발 단계에서도 가능한 빨리 참여하는 것이 중요하다. 구매예정자가 원하는 스타일과 내용을 작가와의 협력을 통해서 만들어내야 하고, 그러한 내용이 과연 애니메이션으로 적합한지를 초기에 판단, 결정해야 하기 때문이다. 기획개발 단계에 대한 연구는 부족하기 때문에 이론화된 모델과 함께 실제사례를 중심으로 한 다양한 관점에서의 연구가 지속되어야 한다.

• 한국항해항만학회지
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• 제32권5호
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• pp.333-339
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• 2008

해상 상태가 거칠어짐에 따라 선체동요로 인하여 선박에 승선 증인 승객 및 승무원은 멀미 증상을 호소하기도 하고, 졸음 증상, 어지럼증, 두통 및 복통 등을 초래하기도 한다. 심한 경우에는 생리적으로 회복하기 힘들 정도의 심각한 장애를 겪기도 한다. 또한, 의욕(동기부여) 감소, 숙련도 저하, 인지능력 및 판단력 저하 등 정신적 활동의 지연이나 오류를 유발하는 등 활동성 및 작업수행 능력이 현저히 떨어지기도 한다. 본 논문에서는 멀미의 발생 및 작업수행과 관련된 대표적인 국제 표준안을 살펴보았고, 실습선에 승선 중인 실습생들을 대상으로 수차례에 걸쳐 설문조사를 실시하여 승선감을 평가하였다. 그 결과, 멀미 중상을 유발하는 주요소가 상하가속도임을 확인하였고, 그 크기(수준)는 0.2g 이상으로 분석되었다. 또한, 속력 또는 침로를 변경하여 파도와의 만남주기가 $4{\sim}8$초의 범위에서 벗어나도록 항해함으로써 멀미 증상을 완화시킬 수 있는 방안을 제시하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.82-93
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• 2008

The flowfield behind two cylinders and flow-induced noise generated from the cylinders in various arrangement are numerically investigated based on the finite difference lattice Boltzmann model with 21 velocity bits. which is introduced a flexible specific heat ${\gamma}$ to simulate diatomic gases like air. In an isolated cylinder with two type of mesh. some flow parameters such as Strouhal number $S_t$ and acoustic pressure ${\Delta}p$ simulated from the solution are given and quantitatively compared with those provided the previous works. The effects of the center-to-center pitch ratio $L_{cc}/d=2.0$ in staggered circular cylinders as shown in Fig. 1 and angles of incidence ${\alpha}=30^{\circ}(T_{cc}/d=0.5)$, $45^{\circ}(T_{cc}/d =0.707)$ and $60^{\circ}\;(T_{cc}/d=0.866)$, respectively, are studied. Our analysis focuses on the small-scale instabilities of vortex shedding, which occurs in staggered arrangement. With the results of drag $C_d$ and lift $C_l$ coefficients and vorticity contours. the mechanisms of the interference phenomenon and its interaction with the two-dimensional vortical structures are present in the flowfields under $Re\;{\le}\;200$. The results show that we successively capture very small pressure fluctuations, with the same frequency of vortex shedding, much smaller than the whole pressure fluctuation around pairs of circular cylinders. The upstream cylinder behaves like an isolated single cylinder, while the downstream one experiences wake-induced flutter. It is expected that, therefore, the relative position of the downstream cylinder has significant effects on the flow-induce noise, hydrodynamic force and vortex shedding characteristics of the cylinders.

• Journal of Advanced Marine Engineering and Technology
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• 제34권4호
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• pp.491-499
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• 2010

관군은 열전달기기에서 광범위하게 사용되고 있어서 전열성능 및 압력강하 특성은 오래전부터 다양한 연구가 진행되어왔다. 기존의 관군에 관한 실험 및 해석은 대부분 25~51mm 직경의 전열관을 이용하여 Reynolds 수 $8.000{\leq}Re{\leq}30.000$ 범위에서 수행되었으나 최근에는 직경 1mm 안팎의 미세관으로 관군을 만들어 열교환기의 밀집도를 높이려는 데 관심이 많다. 본 논문에서는 이전에 다루지 않았던 관 외경 1.5mm의 관군의 전열성능을 $3.000{\leq}Re{\leq}7.000$ 범위에서 전산유체역학을 이용하여 평가하고 기존의 연구 결과들과 비교하였다. 그 결과 튜브직경이 1.5mm인 관군의 열전달계수와 압력손실계수는 $3.000{\leq}Re{\leq}7.000$ 범위에서도 기존의 Zukauskas 상관식과 최대 4.7% 차이 이내로 일치하였다. 또한 튜브의 횡방향 간격을 줄여서 각 열의 전열성능을 높일 수 있음을 확인하였다.