• Title/Summary/Keyword: symmetry index

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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
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    • v.6 no.3
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    • pp.19-26
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    • 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.

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

  • Yi, Bongjo;Yim, Seokhoi
    • Journal of the Korean association of regional geographers
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    • v.20 no.1
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    • pp.30-48
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    • 2014
  • Relying on the interaction indices - dominance index, relative strength index and entropy index, this paper analyzes the structural features of urban network in the Seoul metropolitan area with the flows of commuting, business, and freight. Analytical results show that the Seoul metropolitan urban system is vertical, size-dependent, one-way, and the highest city-dominant network rather than horizontal, size-neutral, two-way, complementary one. The network of freight flow is a little bit more symmetrical than the networks of commuting and business. However, the interaction with Seoul is still determinant in all aspects of hierarchical structure, relative strength, and symmetry of flow.

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

  • Han, Ki Hwan;Kim, Jin Han;Choi, Tae Hyun;Kim, Jun Hyung;Son, Dae Gu
    • Archives of Plastic Surgery
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    • v.35 no.4
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    • pp.431-438
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    • 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.

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

  • Lee, Young-Woo;Kim, Myung-Hee;Kim, Kang-Sung;Lee, Kyung-Ae
    • Korean journal of food and cookery science
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    • v.25 no.3
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    • pp.387-394
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    • 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.

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

  • Lee, Cheong-Hak;Ryu, Boo-Hyung;Kim, Kee-Dae;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2456-2458
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    • 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.

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

  • Ikchoon Lee;Bonsu Lee
    • Journal of the Korean Chemical Society
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    • v.20 no.2
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    • pp.136-140
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    • 1976
  • The photocyclodehydrogenation reaction of o-terphenyl type compounds has been interpreted with perturbational molecular orbital theory. Results show that the mobile bond order for the first excited state is a good reactivity index and this approach is also consistent with the orbital symmetry conservation rule of Woodward and Hoffmann.

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A Finger Dermatoglyphic Study of Maori

  • Cho, Ching
    • Animal cells and systems
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    • v.2 no.2
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    • pp.277-280
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    • 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.

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

  • Kim Sung Min;Kim Sung Jae;Bae Ha Suk;Choi Byoung Cheol
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.5 s.170
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    • pp.197-204
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    • 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.

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

  • Han, Ki-Hwan;Kim, Dae-Jin;Park, Mu-Shik;Kim, Jun-Hyung;Son, Dae-Gu
    • Archives of Plastic Surgery
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    • v.38 no.6
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    • pp.740-746
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    • 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.

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

  • Choi, C.H.;Park, Y.D.;Sim, H.M.;Lee, S.M.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.9 no.1
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    • pp.37-43
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    • 2015
  • In this paper, an efficient system using 3-axis accelerometer is proposed to diagnose the gait imbalance. The proposed hardware system consists of two 3-axis accelerometers to measure 3 directional acceleration of ankles and an embedded system to transfer the data. The acquired data were normalized and then compared to analyze the symmetry between normal and abnormal gait with ROCC (ratio of correlation coefficient). 10 healthy subjects were participated and each subject repeated the experiment 5 times. To make unbalanced ambulation, the height of the heel of one foot was changed during experiments. From the results, it is verified that ROCC index grew apart from the reference according to growing imbalance and the proposed system could be available for estimation of gait imbalance.

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