• 제목/요약/키워드: regular variation

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Occurrence of Modern Planktonic Foraminiferal Species and their Seasonal Variations around Jeju Island, Korea (제주근해에 출현하는 현생 부유성 유공충 종과 계절변화)

  • Hyun, Sangmin;Kimoto, Katsunori;Cho, Sung-Hwan
    • Ocean and Polar Research
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    • v.35 no.2
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    • pp.181-191
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    • 2013
  • To investigate the occurrence of modern living planktonic foraminiferal species and their seasonal variations around Jeju Island, we conducted planktonic foraminiferal sampling at KIOST's regular sampling sites during 16 months. In total seven genus and 16 modern planktonic foraminiferal species were identified with six dominant species. Dominant species were Gloigerinoides sacculifer, Globigerinoides ruber, Globigerina bulloides, Noegloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globorotalia inflata. Most of the species were characterized as being typical subtropical species and showed seasonal variations and/or intermittent occurrence from season to season. The occurrence of living foraminifera revealed a strong relationship with water temperature, but not with salinity. Species succession seems to occur along with water temperature changes. Some patch distribution and water temperature dependences appear to be significant since there is a high degree of variation in the occurrence patterns of species and standing stock. More detailed quantitative study is necessary to confirm the species diversity and seasonal variations of planktonic foraminifera and related ocean environmental changes.

Package Modeling Change in Age of Feeling -Based on Solid Chocolate Package Structure by -√3 Proportion- (Feeling 시대의 Package 조형 변화 -√3 비례에 의한 판 초콜릿 Package 구조를 중심으로-)

  • Kwon, Il-Hyun;Nam, Young-Hyun
    • The Journal of the Korea Contents Association
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    • v.7 no.8
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    • pp.163-173
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    • 2007
  • As present generation live in the age of feeling after been through age of need or age of want, we analyzed Signification based on consumer psychology, sociocultural variation. Based on above, we first built basic modeling from a regular triangle by $\sqrt{3}$ proportion and then approached to substantial modeling of products that enable us to distribute and sell. Furthermore, we built recycle modeling which enables us to create a variety of forms with joy after using products. This means a lot to us in terms of package modeling creation from sans code. Besides, we studied on not only materialistic or functional value of package modeling, but also appropriate semiotics that enable psychological and sociocultural function of package modeling to respond to consumer identity.

A Study on the Nonlinear Rolling Motion of Ship Using Basins of Attraction and Attractors (흡인영역과 끌개의 해석을 통한 선박의 비선형 횡동요운동에 관한 연구)

  • H.S. Lee;S.H. Kwon
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.3
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    • pp.71-82
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    • 1999
  • Irregular motions of nonlinear dynamic system are the result of an intrinsic characteristics that the system have, and sometimes occur unpredictable large motion. For a ship in a regular seaway, the capsizing occur because of this unexpectable motion. So, from the safety's point of view, nonlinear ship motions should be treated carefully. In this study, stable and unstable regions are investigated firstly under the variation of a control external force. Secondly, we consider the attractors to know how ship motions of the stable region that does not undergo capsizing change. Thirdly, bifurcation diagram is considered to study the range in detail where nonlinear chaotic motions are occurred.

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The Role of Lattice Oxygen in the Selective Catalytic Reduction of NOx on V2O5/TiO2 Catalysts (V2O5/TiO2 촉매의 선택적 환원촉매반응에서 격자산소의 역할)

  • Ha, Heon-Phil;Choi, Hee-Lack
    • Korean Journal of Materials Research
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    • v.16 no.5
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    • pp.323-328
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    • 2006
  • In situ electrical conductivity measurements on $V_2O_5WO_3/TiO_2$ catalysts were carried out at between 100 and $300^{\circ}C$ under pure oxygen, NO and $NH_3$ to investigate the reaction mechanism for ammonia SCR (selective catalytic reduction) de NOX. The electrical conductivity of catalysts changed irregularly with supply of NO. It was, however, found that the electrical conductivity change with ammonia supply was regular and the increase of electrical conductivity was mainly caused by reduction of the labile surface oxygen. The electrical conductivity change of catalysts showed close relationship with the conversion rate of NOx. Variation of conversion rate in atmosphere without gaseous oxygen also showed that labile lattice oxygen is indispensable in the initial stage of the de NOx reaction. These results suggest that liable lattice oxygen acts decisive role in the de NOx mechanism. They also support that de NOx reaction occurs through the Eley?Rideal type mechanism. The amount of labile oxygen can be estimated from the measurement of electrical conductivity change for catalysts with ammonia supply. This suggests that measurement of the change can be used as a measure of the de NOx performance.

Fuel properties of biodiesel produced from beef-tallow and corn oil blends based on the variation in the fatty acid methyl ester composition

  • Woo, Duk Gam;Kim, Tae Han
    • Korean Journal of Agricultural Science
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    • v.46 no.4
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    • pp.941-953
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    • 2019
  • Biodiesels are being explored as a clean energy alternative to regular diesel, which causes pollution. In this study, the optimum conditions for producing biodiesel (BD) by combining beef tallow, an animal waste resource with a high saturated fatty acid content, and corn oil, a vegetable oil with a high unsaturated fatty acid content, were investigated, and the fuel properties were analyzed. Furthermore, Multivariate Analysis of Variance (MANOVA) was used to verify the optimum conditions for producing biodiesel. The influences of control factors, such as the oil blend ratio and methanol to oil molar ratio, on the fatty acid methyl ester and biodiesel production yield were investigated. As a result, the optimum condition for producing blended biodiesel was verified to be tallow to corn oil blend ratio of 7 : 3 (TACO7) and a methanol to oil molar ratio of 14 : 1. Moreover, the interaction between the oil blend ratio and the methanol to oil molar ratio has the most crucial effects on the production of oil blended biodiesel. In conclusion, the analysis results of the fuel properties of TACO7 BD satisfied the BD quality standard, and thus, the viability of BD blended with waste tallow as fuel was verified.

The Performance Analysis of the DDFS to drive PLL (PLL을 구동하기 위한 DDFS의 성능분석)

  • 손종원;박창규;김수욱
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.8
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    • pp.1283-1291
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    • 2002
  • In this paper, the PLL driven by the DDFS is designed on the schematic using the Q-logic cell based library and is implemented using FPGA QL32 x16B. The measurement results of the frequency synthesizer switching speed were agreement with a register. The simulated results show that the clock delay was generated after eleven clock and if input is random, It has influence on output DA converter has to be very extensive. Therefore, the DDFS used noise shaper to drive PLL by regular interval for input state. Also the bandwidth of DA converter very extensive, the simulation shows that the variation of small input control word is better than the switching speed of PLL.

Hybrid finite element model for wave transformation analysis (파랑 변형 해석을 위한 복합 유한요소 모형)

  • Jung Tae Hwa;Park Woo Sun;Suh Kyung Duck
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.209-212
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    • 2002
  • Since Berkhoff proposed the mild-slope equation in 1972, it has widely been used for calculation of shallow water wave transformation. Recently, it was extended to give an extended mild-slope equation, which includes the bottom slope squared term and bottom curvature term so as to be capable of modeling wave transformation on rapidly varying topography. These equations were derived by integrating the Laplace equation vertically. In the present study, we develop a finite element model to solve the Laplace equation directly while keeping the same computational efficiency as the mild-slope equation. This model assumes the vertical variation of wave potential as a cosine hyperbolic function as done in the derivation of the mild-slope equation, and the Galerkin method is used to discretize . The computational domain was discretized with proper finite elements, while the radiation condition at infinity was treated by introducing the concept of an infinite element. The upper boundary condition can be either free surface or a solid structure. The applicability of the developed model was verified through example analyses of two-dimensional wave reflection and transmission. .

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Characteristics to ensure Optimum Ease in Men's Business Jackets (남성복 재킷의 선호 여유량과 맞음새에 관한 연구)

  • Kang Yeosun;Choi Hei-Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.1 s.139
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    • pp.91-102
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    • 2005
  • The purpose of this study was to investigate the range of variation for commonly accepted ease in a business jacket and thus to find solutions to the problem of fit and ease in ready-to-wear jackets. This study was based on anthropometric measurements, pattern measurements, which were used to calculate ease amount according to each jacket part. The survey subjects were 493 males, between 25 to 59 years old, buying a jacket at stores in Seoul. In the results, the aesthetic purpose of a business jacket(custom-fit jacket) was clearly observed by the means of controlling the ease amount at chest, waist and hip. The ease at chest and waist(ready-to-wear) clearly revealed a difference among prototypes. This result can be explaned by the regular drops and the similar length-width proportions between sizes in ready-to-wear Jackets. Therefore, customers with varying body drop differences, who had to choose a homogeneous jacket drop, experienced too much ease at the Waist and Hip compared with custom-fit customers. In addition, the height could be an integral factor to affect the ease of jacket length and sleeve length. The ease at these parts was significantly different among height groups and showed negative relationships.

Ruin Probability on Insurance Risk Models (보험위험 확률모형에서의 파산확률)

  • Park, Hyun-Suk;Choi, Jeong-Kyu
    • The Korean Journal of Applied Statistics
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    • v.24 no.4
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    • pp.575-586
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    • 2011
  • In this paper, we study an asymptotic behavior of the finite-time ruin probability of the compound Poisson model in the case that the initial surplus is large. To compare an exact ruin probability with an approximate one, we place the focus on the exact calculation for the ruin probability when the claim size distribution is regularly varying tailed (i.e. exponential claims and inverse Gaussian claims). We estimate an adjustment coefficient in these examples and show the relationship between the adjustment coefficient and the safety premium. The illustration study shows that as the safety premium increases so does the adjustment coefficient. Larger safety premium means lower "long-term risk", which only stands to reason since higher safety premium means a faster rate of safety premium income to offset claims.

Development of a Teacher Rating Scale of Childcare Adaptation for Infants and Toddlers (교사용 영아 어린이집 적응 척도 개발)

  • Shin, Nary;Yun, Hyun Jeong
    • Korean Journal of Child Studies
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    • v.37 no.6
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    • pp.35-56
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    • 2016
  • Objective: This study aimed to develop and validate the Childcare Adaptation Scale for Infants and Toddlers (CASIT), which is rated by teachers of Korean children. Methods: The participants consisted of 326 childcare teachers working with infants (ages 0-2 years). Content validity, discriminant validity, convergent validity, concurrent validity, internal consistency, inter-rater reliability, and item discrimination were examined using PASW 18.0 and AMOS 19.0. Results: The results of an exploratory factor analysis identified the 29-item scale and six dimensions of the scale, including group life adaptation, negative behaviors, positive affect, regular routines, activity/interest, and peer interaction. Convergent validity was examined via confirmatory factor analysis, average variation extracted (AVE), and construct reliability, and acceptable evidences of convergent validity was established. The scales were shown to be highly consistent internally and among raters. Also, the mean between the upper group and lower group of each item regarding item discrimination showed a significant difference. Conclusion: It was concluded that the CASIT, which is a quick and convenient tool for teachers to use, is a valid and reliable instrument.