• Title/Summary/Keyword: 기저

Search Result 2,998, Processing Time 0.039 seconds

Estimable functions of fixed-effects model by projections (사영에 의한 모수모형의 추정가능함수)

  • Choi, Jae-Sung
    • Journal of the Korean Data and Information Science Society
    • /
    • v.23 no.3
    • /
    • pp.487-494
    • /
    • 2012
  • This paper discusses a method for getting a basis set of estimable functions of model parameters in a two-way fixed effects model. Since the fixed effects model has more parameters than those that can be estimated, model parameters are not estimable. So it is not possible to make inferences for nonestimable functions of parameters. When the assumed model of matrix notation is reparameterized by the estimable functions in a basis set, it also discusses how to use projections for the estimation of estimable functions.

Application of Seasonal Alpha Factor using SWAT BFlow Program (SWAT BFlow 프로그램을 이용한 계절별 alpha factor 적용)

  • Kang, Hyun-Woo;Ryu, Ji-Chul;Kum, Dong-Huck;Jeong, Young-Hun;Lim, Kyoung-Jae
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2012.05a
    • /
    • pp.462-462
    • /
    • 2012
  • 수문 분석과 갈수기 유량 산정, 가뭄관리에 직접/기저 유출 분리 및 평가는 매우 중요하며, 이러한 분석을 위하여 많은 모형들이 개발되었고, 실제 유역에 적용되어 연구에 이용되고 있다. 이들 중 Baseflow filter program(BFlow)을 이용한 감수곡선의 Alpha factor 산정 방법이 직접/기저 유출 분리에 널리 이용되고 있다. 하지만 BFlow는 장기 유량 자료를 이용하여 그 유역을 대표할 수 있는 Alpha factor 만을 제시하고 있기 때문에, 계절별/연별로 변화하는 감수곡선의 특성을 정확히 반영하기에는 많은 단점이 있다. 따라서 본 연구에서는 계절별로 변화하는 감수곡선 특성을 조금 더 정확하게 실제 유역에 적용하기 위하여 BFlow 프로그램이용, 장기간의 유량 특성을 분석하여 계절별 Alpha factor를 산정하고 이를 Soil and Water Assessment Tool(SWAT) 모형에 적용하여 기존의 방법과의 차이를 분석하였다. SWAT 모형의 경우 alpha factor가 실제로는 Hydrologic Response Unit (HRU) 별로 활용되기 때문에, 계절별 Alpha factor 산정이 미치는 영향이 실제로 다소 크게 분석되었다. 특히 본 연구에서는 저유량 부분의 차이를 면밀히 분석하여 Alpha factor 저유량 산정에 미치는 영향을 파악하고자 하였으며 이는 SWAT 모형의 단점인 저유량 산정을 개선하는데 기여할 수 있으리라 판단된다.

  • PDF

A Study for Improving Computational Efficiency in Method of Moments with Loop-Star Basis Functions and Preconditioner (루프-스타(Loop-Star) 기저 함수와 전제 조건(Preconditioner)을 이용한 모멘트법의 계산 효율 향상에 대한 연구)

  • Yeom, Jae-Hyun;Park, Hyeon-Gyu;Lee, Hyun-Suck;Chin, Hui-Cheol;Kim, Hyo-Tae;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.23 no.2
    • /
    • pp.169-176
    • /
    • 2012
  • This paper uses loop-star basis functions to overcome the low frequency breakdown problem in method of moments (MoM) based on electric field integral equation(EFIE). In addition, p-Type Multiplicative Schwarz preconditioner (p-MUS) technique is employed to reduce the number of iterations required for the conjugate gradient method(CGM). Low frequency instability with Rao Wilton Glisson(RWG) basis functions in EFIE can be resolved using loop-start basis functions and frequency normalized techniques. However, loop-star basis functions, consisting of irrotational and solenoidal components of RWG basis functions, require a large number of iterations to calculate a solution through iterative methods, such as conjugate gradient method(CGM), due to high condition number. To circumvent this problem, in this paper, the pMUS preconditioner technique is proposed to reduce the number of iterations in CGM. Simulation results show that pMUS preconditioner is much faster than block diagonal preconditioner(BDP) when the sparsity of pMUS is the same as that of BDP.

Effect of Interaction between Category Coherence and Base Rate on Presumption of Reasons for Preference (범주 응집성과 기저율의 상호작용이 선호의 이유 추정에 미치는 효과)

  • Doh, Eun Yeong;Lee, Guk-Hee
    • Korean Journal of Cognitive Science
    • /
    • v.31 no.3
    • /
    • pp.77-102
    • /
    • 2020
  • Some progress has been made in the study of the category coherence effect, which states that the attributes of soldiers or nuns with similarities in dress and behavior, and easily distinguished from other categories, are likely to be generalized. However, few studies have examined the fundamental psychological mechanisms that underlie this category coherence effect, and this study aims to fill this gap. For this purpose, two experiments were conducted after selecting categories with high coherence (nuns, soldiers, and flight attendants) and those with low coherence (interpreters, wedding planners, and florists). In experiment 1, we observed that the members of a category were presumed to have certain reasons to prefer [property X] (presumption of reasons for preference), with this presumption becoming stronger when [property X] was observed repeatedly in high-coherence categories than in the case of low-coherence categories. Experiment 2 showed that for the high-coherence categories, the presumption of reasons for preference was stronger when [property X], rarely seen in everyday life (base rate of 30%), was observed, while the presumption of reasons for preference was weaker when [property Y] (base rate 70%), frequently seen in everyday life, was observed. In the low-coherence categories, the presumption of reasons for preference tended to be weak for both rare and frequent attributes. That is, there were significant effects of the two-way interaction between category coherence and base rate on the presumption of reasons for preference. This study has implications for psychological essentialism and stereotyping.

A screening of Alzheimer's disease using basis synthesis by singular value decomposition from Raman spectra of platelet (혈소판 라만 스펙트럼에서 특이값 분해에 의한 기저 합성을 통한 알츠하이머병 검출)

  • Park, Aaron;Baek, Sung-June
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.14 no.5
    • /
    • pp.2393-2399
    • /
    • 2013
  • In this paper, we proposed a method to screening of Alzheimer's disease (AD) from Raman spectra of platelet with synthesis of basis spectra using singular value decomposition (SVD). Raman spectra of platelet from AD transgenic mice are preprocessed with denoising, removal background and normalization method. The column vectors of each data matrix consist of Raman spectrum of AD and normal (NR). The matrix is factorized using SVD algorithm and then the basis spectra of AD and NR are determined by 12 column vectors of each matrix. The classification process is completed by select the class that minimized the root-mean-square error between the validation spectrum and the linear synthesized spectrum of the basis spectra. According to the experiments involving 278 Raman spectra, the proposed method gave about 97.6% classification rate, which is better performance about 6.1% than multi-layer perceptron (MLP) with extracted features using principle components analysis (PCA). The results show that the basis spectra using SVD is well suited for the diagnosis of AD by Raman spectra from platelet.

A COMPARATIVE STUDY OF BOND STRENGTH OF RECYCLED BRACKETS (재생 브라켓의 전단접착강도에 관한 비교 연구)

  • Shur, Cheong-Hoon;Choi, Eun-Ah
    • The korean journal of orthodontics
    • /
    • v.28 no.4 s.69
    • /
    • pp.641-657
    • /
    • 1998
  • This study was undertaken to compare the bond strength and the fracture site of new and recycled brackets according to the base design. 252 sound premolars extracted for orthodontic treatment were collected and Type I, Type II, Type III brackets were divided into four groups by recycling method Each bracket was then bonded to an extracted premolar. Instron Universal Testing Machine(model W) was used to measure the shear bond strength, and the surface of the recycled brackets were viewed in SEM For the analysis of the results, one way ANOVA and Scheffe's multiple range test was executed using the SPSSWIN program. 1. The shear bond strength showed statistically significant difference according to the bracket base design(p<0.001). Type III bracket(round indentation base, micro-etched) showed the highest bond strength, Type I bracket(foil-mesh base) was second, and Type II bracket(grooved integral base, micro-etched) was last. 2. The effect of recycling on the bond strength was different according to bracket type. The shear bond strength of Type I, Type II brackets showed the smallist reduction when treated for 1 minute in Big Jane(p<0.05), but the shear bond strength of Type III brackets showed no statistically significant difference according to recycling method(p>0.05). 3. In Type I, Type II brackets, frequent fracture site was bracket-resin interface, but in Type III brackets, about half of the resin was retained on the tooth surface frequently. 4. The shear bond strength was highest when about half of the resin was retained on the tooth surface(p<0.05). 5. The resin remnant on the bracket base after recycling had no effect on the shear bond strength.

  • PDF

NEVOID BASAL CELL CARCINOMA SYNDROME : A REPORT OF CASE (기저세포모반 증후군 환아의 증례보고)

  • Heo, Su-Kyung;Choi, Nam-Ki;Kim, Seon-Mi;Yang, Kyu-Ho
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.35 no.4
    • /
    • pp.725-730
    • /
    • 2008
  • Nevoid basal cell carcinoma syndrome is an ecto-mesodermal polydysplasia with numerous manifestations that affect multiple organs. The syndrome is an autosomal dominant inherited, with a high penetration and visible expression. The syndrome is characterized by a series of associated anomalies such as cutaneous, dentofacial, skeletal, ophthalmologic, neurological, and genital anomalies. Generally, the jaw cysts are multiple odontogenic keratocysts, affecting any area of maxilla and mandible. Multiple odontogenic keratocysts of this syndrome are more recurrent than the keratocysts of non-syndrome, thus they are treated aggressively for complete removal. We report a case of multiple jaw cysts associated with nevoid basal cell carcinoma syndrome. In clinical and radiological examinations, frontal bossing, hypertelorism, mild mental retardation and two odontogenic keratocysts in both the maxilla and mandible were observed. Two cysts were treated by marsupialization. For the management of eruption of unerupted teeth, periodic recall check and orthodontic treatment are required.

  • PDF

Iris Feature Extraction using Independent Component Analysis (독립 성분 분석 방법을 이용한 홍채 특징 추출)

  • 노승인;배광혁;박강령;김재희
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.40 no.6
    • /
    • pp.20-30
    • /
    • 2003
  • In a conventional method based on quadrature 2D Gator wavelets to extract iris features, the iris recognition is performed by a 256-byte iris code, which is computed by applying the Gabor wavelets to a given area of the iris. However, there is a code redundancy because the iris code is generated by basis functions without considering the characteristics of the iris texture. Therefore, the size of the iris code is increased unnecessarily. In this paper, we propose a new feature extraction algorithm based on the ICA (Independent Component Analysis) for a compact iris code. We implemented the ICA to generate optimal basis functions which could represent iris signals efficiently. In practice the coefficients of the ICA expansions are used as feature vectors. Then iris feature vectors are encoded into the iris code for storing and comparing an individual's iris patterns. Additionally, we introduce two methods to enhance the recognition performance of the ICA. The first is to reorganize the ICA bases and the second is to use a different ICA bases set. Experimental results show that our proposed method has a similar EER (Equal Error Rate) as a conventional method based on the Gator wavelets, and the iris code size of our proposed methods is four times smaller than that of the Gabor wavelets.

Ultrastructure of the Compound Eye of the Rice Brown Planthopper, Nilaparvata lugens (StaL) (Homopteera : Auchenorhyncha : Delphacidae) (벼멸구 겹눈의 미세구조)

  • Young Nam Youn
    • Korean journal of applied entomology
    • /
    • v.34 no.3
    • /
    • pp.266-277
    • /
    • 1995
  • The adult brown planthopper possesses tow oval shaped compound eyes which, on their ventral borders, curve around the base of the antennae. Compound eye of the adult brown planthopper is recognised apposition eye which each ommatidium is optically isolated from it surroundings, the rhabdoms receiving light only from their own corneal lens. Each ommatidium possesses its own dioptric apparatus formed from the cuticular cornea and an underlying crystalline cone. The retinula cells lying immediately beneath the crystalline cone have their individual rhabdomeres tightly opposed to form one central, closed rhbdom. The rhabdom stretches from the spex of the crystalline cone nearly to the basement membrane and is approximately 110~120 $\mu\textrm{m}$ in length. The crystalline cone is surrounded by a pair of primary pigment cells an these in turn are surrounded by accessory pigment cells. Accessory pigment cells extend beyond the crystalline cone surrounding the retinular cells in the distal region of the eye. The crystalline cone is surrounded by the distal-most regions of the retinula cells show the presence of seven cells and sections taken proximally in the last quarter of the omatidium before the basement membrane is reached, reveal the presence of a small, eighth retinula cell which also contributes to the central rhabdom. Each ommatidium has a central rhabdom formed from the modified inner border of all of the retinula cells. Th rhabdom consists of micrvilli arising from the inner wall of each retinula cell. In cross section th microvilli exhibit a characteristic honeycomb appearance. Pigment cells comprise the primary pigment cells enveloping the crystalline cone, the accessory pigment cells extending from the inner surface of the comea to the basement membrane and the small pigment cells of the basement membrane.

  • PDF

A Case Report : Hypersexuality and Obsessive-Compulsive Behaviors in a Stroke Patient with the Left Mesial Frontal Cortex and Both Basal Ganglia Lesion (좌측 정중 전두엽과 양측 기저절 경색 후 과잉성욕 증상과 강박 증상을 보인 환자 1례)

  • Kim, Se Joo;Kim, Young Shin;Choi, Nak Kyung;Lee, Byung-Chul;Lee, Man Hong
    • Korean Journal of Biological Psychiatry
    • /
    • v.8 no.2
    • /
    • pp.271-275
    • /
    • 2001
  • Hyposexuality after stroke has been frequently observed, but hypersexuality as a sequela of stroke has not been commonly documented. We report a patient who exhibited hypersexuality and obsessive-compulsive behaviors after stroke in the region of the left mesial frontal cortex and both basal ganglia. At 2 months after stroke, he visited psychiatric unit due to these symptoms. His motor function was almost full recovered. He was treated with fluvoxamine and perphenazine. With two-month medication, his hypersexuality and obsessive-compulsive behavior disappeared. This case may indicate that basal ganglia-thalamocortical circuit plays an important role in the mediation of sexual behavior and obsessive-compulsive behavior. Since changes in sexual activity may not be spontaneously reported, a systemic inquiry into patient's sexual functioning after infarction in frontal lobe or basal ganglia is warranted.

  • PDF