• 제목/요약/키워드: Symmetry Index

검색결과 102건 처리시간 0.028초

Modeling Stock Price Volatility: Empirical Evidence from the Ho Chi Minh City Stock Exchange in Vietnam

  • NGUYEN, Cuong Thanh;NGUYEN, Manh Huu
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제6권3호
    • /
    • pp.19-26
    • /
    • 2019
  • The paper aims to measure stock price volatility on Ho Chi Minh stock exchange (HSX). We apply symmetric models (GARCH, GARCH-M) and asymmetry (EGARCH and TGARCH) to measure stock price volatility on HSX. We used time series data including the daily closed price of VN-Index during 1/03/2001-1/03/2019 with 4375 observations. The results show that GARCH (1,1) and EGARCH (1,1) models are the most suitable models to measure both symmetry and asymmetry volatility level of VN-Index. The study also provides evidence for the existence of asymmetric effects (leverage) through the parameters of TGARCH model (1,1), showing that positive shocks have a significant effect on the conditional variance (volatility). This result implies that the volatility of stock returns has a big impact on future market movements under the impact of shocks, while asymmetric volatility increase market risk, thus increase the attractiveness of the stock market. The research results are useful reference information to help investors in forecasting the expected profit rate of the HSX, and also the risks along with market fluctuations in order to take appropriate adjust to the portfolios. From this study's results, we can see risk prediction models such as GARCH can be better used in risk forecasting especially.

상호작용 지수를 이용한 수도권 도시 네트워크 분석 (An Analysis of Urban Network in Seoul Metropolitan Area by Interaction Indices)

  • 이봉조;임석회
    • 한국지역지리학회지
    • /
    • 제20권1호
    • /
    • pp.30-48
    • /
    • 2014
  • 본 연구는 도시 간 상호작용 지수(지배력 지수, 상대적 강도 지수, 엔트로피 지수)를 활용하여 출근 흐름과 업무 흐름, 화물 흐름에 있어서 수도권 도시 네트워크의 구조적 특성을 분석하였다. 분석 결과는 수도권의 도시 네트워크가 흔히 네트워크형 도시체계론에서 말하는 수평적이고 상호보완적이며 양방향과 규모 중립적이기 보다는 매우 규모 의존적이고, 수직적이고 최고차 중심도시에 의존적하는 지배 종속적 구조를 가지고 있는 것으로 나타났다. 출근 업무 흐름에 비해 화물 흐름의 네트워크가 다소 균형적이기는 하지만, 상호작용의 계층 구조, 흐름의 상대적 강도, 균형성 등 모든 면에서 출근 업무 흐름이든, 화물 흐름이든 서울과의 상호작용이 결정적이다.

  • PDF

일측성 구순열비변형에서 다공성 폴리에틸렌 판을 이용한 상악골이상구증대술 (Augmentation of Pyriform Margin Using Porous High-Density Polyethylene Sheet In Unilateral Cleft Lip Nasal Deformity)

  • 한기환;김진한;최태현;김준형;손대구
    • Archives of Plastic Surgery
    • /
    • 제35권4호
    • /
    • pp.431-438
    • /
    • 2008
  • Purpose: The common deformity after the correction of unilateral cleft lip nasal deformity is nasal asymmetry, and it is caused by the hypoplasia of the pyriform aperture. To correct this, many procedures have been applied, but still many problems are present. Authors performed the inlay and onlay insertion of porous high density polyethylene sheet(1 mm thickness $Medpor{(R)}$ sheet) in the hypoplastic pyriform margin of cleft side and obtained satisfactory results. Methods: 11 cases were performed and the mean follow up period was 15.1 months. Their mean age was 23.6 years. Under general anesthesia, bilateral pyriform margin was exposed. $Medpor{(R)}$ sheets in "match stick" like shaped were inlay inserted, and kidney shaped were onlay inserted fixating with two 6 mm titanium screws. After the surgery, the results was evaluated by photogrammetric analysis. On the basal view, the distance from the subalare and labiale superius' to the transverse baseline connecting the both cheilions was measured from the cleft side and the non-cleft side. Then, the postoperative symmetry was assessed by obtaining the cleft side against the non-cleft side as proportion index, defined as lateral and medial upper lip contour index. Results: There were 2 infections. The cause was because the inserted implant was too long and thus protruded to the base of nasal cavity. The lateral upper lip contour index was from 95.49 to 103.27, and medial upper lip contour index was from 90.92 to 100.49, it was statistically increased, and thus the symmetry was improved. However clinically mild depression remained at nostril floor. Conclusion: Authors performed porous high density polyethylene sheet inlay and onlay insertion for the hypoplasia of the pyriform margin in unilateral cleft lip nasal deformity. It was found that depressed pyriform margin and upper lip were corrected effectively except for the nostril floor, for which an additional soft tissue augmentation would be necessary. The inlay insertion has risk of protrusion, thus the guideline of the use of artificial prosthesis should be observed strictly.

두유 요구르트 분말을 첨가한 증편의 품질특성 (A Study on the Quality Properties of Jeungpyun Added with Soybean Yogurt)

  • 이영우;김명희;김강성;이경애
    • 한국식품조리과학회지
    • /
    • 제25권3호
    • /
    • pp.387-394
    • /
    • 2009
  • This study was performed to determine the quality characteristics of Jeungpyun with the addition of soy yogurt (0%,3%, 6%, 9%, 12%). The proximate composition analysis showed that moisture contents of Jeungpyun were 49.87${\sim}$51.60%, and crush protein, lipid and ash contents were 2.58%, 0.21${\sim}$0.33% and 0.58${\sim}$1.05%, respectively. The pH ofJeungpyun was higher as the additive increased. Volume and symmetry index were higher as the additive increased, but uniformity index was no significant difference. L value and a value were the lowest in control group and increased with soy yogurt addition, while b value was decreased as amount of soy yogurt. Hardness, cohesiveness, gumminess were the highest in 9% group, springiness was the lowest in 9% group. In surface structure of Jeungpyun observed by SEM, cell size was the smallest and the cell uniformity was most regular in 12% group. According to sensory evaluation, appearance, taste and overall acceptance were highest in Jeungpyun with 9% soy yogurt. Therefore, Jeungpyun containing 9% soy yogurt was most preferable.

이종 접합된 광섬유에 있어서 편광모드분산 특성에 관한 연구 (A Study on Polarization Mode Dispersion Properties of Concatenated Optical Fibers)

  • 이청학;류부형;김기대;박대희
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1999년도 하계학술대회 논문집 E
    • /
    • pp.2456-2458
    • /
    • 1999
  • The polarization mode dispersion (PMD) that restricts the transmission bandwidth was investigated in standard long single mode fiber which optimized at 1.3${\mu}m$. Although fiber has perfect circular symmetry, each optical fiber has different refractive index profiles. The investigation of PMD with random mode couplings were conducted in three kinds of fiber by the time-domain interferometric method. By using two manufacturing methods, MCVD(Modified Chemical Vapor Deposition) method and VAD(Vapor Phase Axial Deposition) method, the property of mechanical asymmetric lateral pressure, bending and twisting induced polarization mode dispersion were measured. The concatenated optical fibers were compared with other types.

  • PDF

화학반응성의 분자궤도론적 연구 (제8보). o-Terphenyl 형 화합물의 광학적탈수소 고리화 반응에 대한 섭동분자궤도론적 해석 (Determination of Reactivity by MO Theory (VIII). PMO Interpretation for Photocyclodehydrogenation of o-Terphenyl-type compounds)

  • 이익춘;이본수
    • 대한화학회지
    • /
    • 제20권2호
    • /
    • pp.136-140
    • /
    • 1976
  • 오르토-터페닐계 화합물들의 광화학적 탈수소 고리화 반응을 섭동분자궤도론적으로 다루었으며 일차 들뜬 상태의 가동결합차수가 반응성의 좋은 지표가 될 수 있음을 밝혔다. 이 해석은 Woodward-Hoffman의 궤도함수 대칭성 보존법칙에도 부합된다.

  • PDF

A Finger Dermatoglyphic Study of Maori

  • Cho, Ching
    • Animal cells and systems
    • /
    • 제2권2호
    • /
    • pp.277-280
    • /
    • 1998
  • Fingerprints of 104 New Zealand Maori males and 98 females have been analyzed. Whorls are more abundant in females (55.0%) than in males(47.3%). The index of pattern intensity reveals a higher va1ue in females(15.39) than in males (14.52). The bimanual differences both in males and females are not statistically significant for the occurrence of pattern on the digits of the right and left hands. The difference between the sexes in occurrence of patterns is not statistically significant. Incidences of actual symmetry on the homologous digits represented a mean of 78.8% in all subjects. The mean total ridge counts showed 161.7 in females and 159.6 in males, respectively. Thus, the Maori show greater affinities with the Mongoloids in quantitative dermatoglyphics.

  • PDF

지면반발력을 이용한 인공족관절의 보행평가 기법에 관한 연구 (A Study on The Assessment Method of Gait Analysis for Ankle Assembly Using Ground Reaction Force)

  • 김성민;김성재;배하석;최병철
    • 한국정밀공학회지
    • /
    • 제22권5호
    • /
    • pp.197-204
    • /
    • 2005
  • In this study, ground reaction force(GRF), absolute symmetry index(ASI) and coefficient of variation(CV) of fixed, single-axis and multi-axis prosthetic ankle assemblies were investigated to show the biomechanical evaluation for above knee amputees. In the experiments, 37 normal male volunteers, two male and two female AK amputees were tested with fixed, single-axis and multi-axis prosthetic ankle assembly. A gait analysis was carried out to derive the ratio of GRF to weight as the percentage of total stance phase for ten points. The results showed that fixed-axis ankle was superior to the other two ankle assemblies for the characteristic of forwarding and breaking forces. Multi-axis ankle was relatively superior to the other two ankle assemblies for gait balancing and movement of the center for mass. single-axis ankle was relatively superior to the other two ankle assemblies for CV and ASI of GRF.

일측구순열비변형에서 물갈퀴일측지Z성형술을 이용한 외비공과 비주의 재건: 사진계측학적 연구 (Web Uni-Limb Z-Plasty for Correction of Alar Web Deformity in Unilateral Cleft Lip Nasal Deformities: Photogrammetric Analysis)

  • 한기환;김대진;박무식;김준형;손대구
    • Archives of Plastic Surgery
    • /
    • 제38권6호
    • /
    • pp.740-746
    • /
    • 2011
  • Purpose: In the treatment of the unilateral cleft lip nasal deformities, the correction of the low-nostril height and short-columella are very difficult problems. We report the treatment outcomes of web uni-limb Z-plasty used for correction of unilateral cleft lip nasal deformities by using photographic analysis. Methods: A total of 36 patients with unilateral cleft lip nasal deformities were enrolled in this study, who underwent web uni-limb Z-plasty and were followed up for at least 6 months. First, a triangular flap was made on the medial side of alar-columella web. The nostril apex of cleft side was corrected to a higher point compared to noncleft side by 2 mm. The flap was transposed into the defect of the vestibule. To reduce the bulging of the flap, horizontal cinching sutures were added. Postoperative outcomes were evaluated by using photographic analysis. 2 indices and 1 angle were measured on their photographs taken before and after the surgery. Symmetry was also evaluated by means of the noncleft side to cleft side index. For anthropologic assessment, observers described postoperative outcomes, using Ordinary Scale Method. Results: The postoperative values obtained in photographic analysis improved compared to preoperative ones. More improving anthropologic assessment was shown in post-than pre-operative. Conclusion: Although, further long term follow up is needed, we found this technique to be an effective procedure to the symmetry of nostril apex level and the lengthening of columella in the unilateral cleft lip nasal deformities.

3축 가속도 센서를 이용한 보행 불균형 평가 시스템에 관한 연구 (A Study on Gait Imbalance Estimation System using 3-axis Accelerometer)

  • 최항적;박용덕;심현민;이상민
    • 재활복지공학회논문지
    • /
    • 제9권1호
    • /
    • pp.37-43
    • /
    • 2015
  • 본 논문에서는 3축 가속도 센서를 이용하여 보행 불균형을 진단하는 효율적 시스템을 제안한다. 제안된 하드웨어 시스템은 주로 보행시 발목 세 방향의 가속도를 무선으로 측정할 수 있는 3축 가속도 센서와 데이터 전송을 위한 임베디드 시스템으로 구성되어 있다. 획득된 데이터를 정규화 처리한 후, ROCC (ratio of correlation coefficient)를 이용하여 정상적인 보행의 대칭성과 비정상적인 보행의 대칭성을 비교 분석하였다. 건강한 성인 10명을 대상으로 실험을 실시하였고 개인당 총 5회 반복 실험을 하였다. 비정상 보행을 만들기 위해 한쪽 발의 굽의 높이를 변화시켰다. 결과를 보면 보행 불균형이 커질수록 ROCC의 값이 점차 기준에서 멀어지는 것을 알 수 있었으며 제안된 시스템이 보행 불균형 평가에 사용가능한 것이 확인되었다.

  • PDF