• 제목/요약/키워드: traces

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GENERATING FUNCTION OF TRACES OF SINGULAR MODULI

  • Kim, Chang Heon
    • 충청수학회지
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    • 제20권4호
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    • pp.375-386
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    • 2007
  • Let p be a prime and $f(z)=\Sigma_{n}a(n)q^n$ be a weakly holomorphic modular function for ${\Gamma}^*_0(p)$ with a(0) = 0. We use Bruinier and Funke's work to find the generating series of modular traces of f(z) as Jacobi forms.

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구석기시대의 석기에서 관찰된 본 자국의 연구 - 전곡리와 수양개 유적의 유물을 중심으로 - (A Study of Use-wear on Stone Artefacts from Chongong-ni and Suyanggae Palaeolithic Site)

  • 이기길
    • 고문화
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    • 32호
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    • pp.3-13
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    • 1988
  • Stone artefacts when flaked or used retain traces. It is my objectives to analyze such traces as observed on the artefacts collected and excavated from Chongong-ni and Suyanggae sites attributed to palaeolithic ages. Observations were made with 1) naked e

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해상 소형 낙하물 입수흔적의 크기 예측 및 검증 (Prediction and Verification of Water-entry Traces Size of Small Falling Objects into the Sea)

  • 민안기;황태원
    • 한국군사과학기술학회지
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    • 제18권2호
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    • pp.146-153
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    • 2015
  • An unmanned aerial photography method by using an unmanned helicopter is useful method for measuring of the water-entry traces of small falling objects into the sea. Pixel sizes on the aerial photograph may be too large due to a limit of camcorder resolution and a wide shooting area. If the pixel size is too large, identification of water-entry trace is impossible. Thus an accurate prediction of water-entry trace size is required. The traces of water-entry could be classified into three types such as splash, water column, and bubble. Diameters of each trace are predicted by water-entry impact pressure theories, cavity theories, and trial test results. The results are verified by drop tests using an unmanned helicopter at two water-entry speeds. As a result, prediction and test results showed sufficient similarity to evaluate the identifiability of water-entry trace.

Influence of scaling procedures on the integrity of titanium nitride coated CAD/CAM abutments

  • Gehrke, Peter;Spanos, Emmanouil;Fischer, Carsten;Storck, Helmut;Tebbel, Florian;Duddeck, Dirk
    • The Journal of Advanced Prosthodontics
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    • 제10권3호
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    • pp.197-204
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    • 2018
  • PURPOSE. To determine the extent of treatment traces, the roughness depth, and the quantity of titanium nitride (TiN) removed from the surface of CAD/CAM abutments after treatment with various instruments. MATERIALS AND METHODS. Twelve TiN coated CAD/CAM abutments were investigated for an in vitro study. In the test group (9), each abutment surface was subjected twice (150 g vs. 200 g pressure) to standardized treatment in a simulated prophylaxis measure with the following instruments: acrylic scaler, titanium curette, and ultrasonic scaler with steel tip. Three abutments were used as control group. Average surface roughness (Sa) and developed interfacial area ratio (Sdr) of treated and untreated surfaces were measured with a profilometer. The extent of treatment traces were analyzed by scanning electron microscopy. RESULTS. Manipulation with ultrasonic scalers resulted in a significant increase of average surface roughness (Sa, P<.05) and developed interfacial area ratio (Sdr, P<.018). Variable contact pressure did not yield any statistically significant difference on Sa-values for all instruments (P=.8). Ultrasonic treatment resulted in pronounced surface traces and partially detachment of the TiN coating. While titanium curettes caused predominantly moderate treatment traces, no traces or detectable substance removal has been determined after manipulation with acrylic curettes. CONCLUSION. Inappropriate instruments during regular plaque control may have an adverse effect on the integrity of the TiN coating of CAD/CAM abutments. To prevent defects and an increased surface roughness at the transmucosal zone of TiN abutments, only acrylic scaling instruments can be recommended for regular maintenance care.

Automatic detection of discontinuity trace maps: A study of image processing techniques in building stone mines

  • Mojtaba Taghizadeh;Reza Khalou Kakaee;Hossein Mirzaee Nasirabad;Farhan A. Alenizi
    • Geomechanics and Engineering
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    • 제36권3호
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    • pp.205-215
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    • 2024
  • Manually mapping fractures in construction stone mines is challenging, time-consuming, and hazardous. In this method, there is no physical access to all points. In contrast, digital image processing offers a safe, cost-effective, and fast alternative, with the capability to map all joints. In this study, two methods of detecting the trace of discontinuities using image processing in construction stone mines are presented. To achieve this, we employ two modified Hough transform algorithms and the degree of neighborhood technique. Initially, we introduced a method for selecting the best edge detector and smoothing algorithms. Subsequently, the Canny detector and median smoother were identified as the most efficient tools. To trace discontinuities using the mentioned methods, common preprocessing steps were initially applied to the image. Following this, each of the two algorithms followed a distinct approach. The Hough transform algorithm was first applied to the image, and the traces were represented through line drawings. Subsequently, the Hough transform results were refined using fuzzy clustering and reduced clustering algorithms, along with a novel algorithm known as the farthest points' algorithm. Additionally, we developed another algorithm, the degree of neighborhood, tailored for detecting discontinuity traces in construction stones. After completing the common preprocessing steps, the thinning operation was performed on the target image, and the degree of neighborhood for lineament pixels was determined. Subsequently, short lines were removed, and the discontinuities were determined based on the degree of neighborhood. In the final step, we connected lines that were previously separated using the method to be described. The comparison of results demonstrates that image processing is a suitable tool for identifying rock mass discontinuity traces. Finally, a comparison of two images from different construction stone mines presented at the end of this study reveals that in images with fewer traces of discontinuities and a softer texture, both algorithms effectively detect the discontinuity traces.

포장지의 발수도 자동 해석 시스템 개발 -KS M 7057에 근거한 발수도 자동 측정- (Development of Automatic Analysis System for Water Repellency of Packaging Paper -Automatic Measurement of Water Repellency Based on KS M 7057-)

  • 김철환;최경민;강진기;박종열
    • 펄프종이기술
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    • 제35권1호
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    • pp.7-12
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    • 2003
  • The test results for water repellency of paper and paperboard according to KS M 7057 can readily be influenced by an operator's bias. In order to discard such bias, the automatic analysis program of water repellency was developed based on different shape features of a liquid trace formed on a specimen. That is, the shape of a liquid track flowing down on the specimen with an angle of $45^{\circ}$ was evaluated according to width variation between head and tail of the trace($S_{Hr}$), uniformity of a liquid flow($S_{d}$), length of long traces($L_{SHr}$), eccentricity of liquid traces($E_{i}$), and then was recognized as a specific degree of water repellency. Finally, the automatic analysis system of water repellency based upon KS M 7057 made it possible to readily measure water resistance of paper and paperboards classified into R0 to R10.

배재대학교 캠퍼스 외부 공간에 관한 연구 (A Study on the Outdoor Space of Campus in Paichai University)

  • 이시영
    • 자연과학논문집
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    • 제15권1호
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    • pp.111-125
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    • 2005
  • This study aims at reconsidering the spacial structure and suggesting guidelines for campus planning and design with spatial reference to the Campus of PaiChai university, area $208,499m^2$, Taejon. This study is mainly based on user's behavior and physical traces and questionnaire survey. User's behavior and physical traces were carefully observed by 20 students of dept. of landscape architecture at each alloted zone, 6 zones in Campus. Questionnaire survey, consisted of user attitudes, use satisfaction factors and personal items was carried out to 320 persons. As a result, the item of 'rest' shows the highest mean and the item of 'chatting' and 'meeting' follows to utilization purpose. The length of stay is generally 30minute to 1hour. The factor analysis, on the object of 32 items except 4 item, appeared 8 factors: visual elements, activity, vehicle, plants, practicality of street furniture, bench, spacial use and shade.

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중소기업형 인사관리를 위한 e-HRM 시스템 설계 (A Design of e-HRM System for Small and Medium Eenterprises Personnel Management)

  • 성경
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2008년도 추계종합학술대회 B
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    • pp.810-813
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    • 2008
  • 디지털시대에 기업경쟁력의 원천으로서 인적자본의 중요성 인식을 급격히 확대하기에 이르렀고 경쟁력 있는 인적자원을 보다 효율적으로 관리하기 위한 인적자원관리시스템의 필요성이 증대되었다. 본 논문에서는 BSC(Balanced ScroreCard)를 이용하여 인사고과 척도를 적용하여 다양한 관점의 평가관리와 AHP(Analytic Hierarchy Process) 기반의 가중치 부여로 효과적인 의사결정을 반영하는 중소기업형 e-HRM 프로토타입 시스템을 개발하였다.

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고속 시스템에서의 PCB 선로의 SPICE 모델 (SPICE models of PCB traces in high-speed systems)

  • 남상식;손진우;강석열;김석윤
    • 한국통신학회논문지
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    • 제22권1호
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    • pp.12-20
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    • 1997
  • Physical interconnect such as Printed Circuit Board(PCB) traces introduces new challenges for parameter extraction and delay calculation for high-speed system design. PCB traces are dominated by frequency dependent LC propagation which makes precharacterization difficult for all possible configurations. Moreover, simulating the transient behavior of the trace for noise and delay analysis requries the combined used of a variety of models and techniques for efficiently handling lossy, low-loss, frequency dependent, and coupled transmission lines together with lumped elements. In this paper we explain how the frequency dependence caused by ground plane proximity and skin effects can be modeled using the adstracted models. These abstracted (lumped) models are SPICE-compatible and can be simulated in time-domain, along with precharacterized lumped parasitic elements and nonlinear driver and load models.

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다공성 수침-평판전극간의 수적 방출 특성 (Water Droplet Ejection Characteristics of a Wet Porous Point-Plate Airgap)

  • 정재승;이우석;문재덕
    • 전기학회논문지
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    • 제58권10호
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    • pp.2005-2010
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    • 2009
  • Water droplet ejection characteristics of a point-to-plate airgap, with a wet porous point as a corona electrode, has been investigated. And the water droplet traces, charge, mass and number were measured experimentally. More particles are observed with wet porous point than metal point because the corona-discharging wet porous point can eject a number of water droplets. The water droplets ejected from the positive-corona-discharging wet porous point showed very fine traces as compared with those from the negative-corona-discharging wet porous point. Moreover, the water droplets ejected from the AC-corona-discharging wet porous point showed granular-like larger traces. It was shown that the weak corona discharge can eject smaller water droplets with larger ratio of mass-to-charge than the intense corona discharge.