• Title/Summary/Keyword: Asymmetry Index

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Comparison of the Symmetry of Buttock Pressure during Simulated Driving between Heathy Adults and Patients with Stroke

  • Shin, Hwa-Kyung;Lee, Du-Hwan
    • The Journal of Korean Physical Therapy
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    • v.29 no.4
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    • pp.218-222
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    • 2017
  • Purpose: Driving is an important activity that is affected by various motor and cognitive deficits after stroke. On the other hand, there is no standard screening tool to evaluate the sitting asymmetry during driving, which is the stereotyped postural characteristic observed in patients with stroke. Therefore, this study compared the buttock pressure during simulated driving between healthy adults and patients with stroke. Methods: Ten post-stroke patients and ten healthy subjects participated in the experiment. The participants experienced simulated driving of 6.1 km during approximately 5 minutes for adaptation. The driving scenario consisted of 3.5 km urban traffic conditions, 10 km straight highway, and 7 km curved or hilly rural roads. Force sensitive application (FSA) was used to analyze the distribution of the buttock pressure on the driver's seat. The symmetry index (SI) was determined using the average buttock pressure of each side of the buttock. The closer SI is to zero, the higher the symmetry of buttock pressure. Results: These studies showed that the SI of healthy subjects was significantly closer to zero than that of the stroke patients. Conclusion: The buttock pressure of the stroke patients showed more asymmetry than that of the healthy subjects during simulated driving. Therefore, a therapeutic approach is needed for symmetrical sitting to improve the driving performance.

Life Cycle of Index Derivatives and Trading Behavior by Investor Types (주가지수 파생상품 Life Cycle과 투자자 유형별 거래행태)

  • Oh, Seung-Hyun;Hahn, Sang-Buhm
    • The Korean Journal of Financial Management
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    • v.25 no.2
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    • pp.165-190
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    • 2008
  • The degree of informational asymmetry relating to the expiration of index derivatives is usually increased as an expiration day of index derivatives approaches. The increase in the degree of informational asymmetry may have some effects on trading behavior of investors. To examine what the effects look like, 'life cycle of index derivatives' in this study is defined as three adjacent periods around expiration day: pre-expiration period(a week before the expiration day), post-expiration period(a week after the expiration day), and remaining period. It is inspected whether stock investor's trading behavior is changed according to the life cycle of KOSPI200 derivatives and what the reason of the changing behavior is. We have four results. First, trading behavior of each investor group is categorized into three patterns: ㄱ-pattern, L-pattern and U-pattern. The level of trading activity is low for pre-expiration period and normal for other periods in the ㄱ-pattern. L-pattern means that the level of trading activity is high for post-expiration period and normal for other periods. In the U-pattern, the trading activity is reduced for remaining period compared to other periods. Second, individual investors have ㄱ-pattern of trading large stocks according to the life cycle of KOSPI200 index futures while they show U-pattern according to the life cycle of KOSPI200 index options. Their trading behavior is consistent with the prediction of Foster and Viswanathan(1990)'s model for strategic liquidity investors. Third, trading pattern of foreign investors in relation to life cycle of index derivatives is partially explained by the model, but trading pattern of institutional investors has nothing to do with the predictions of the model.

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Measuring of Gender Inequality: Asymmetry of Marriage Table with respect to Educational Level (교육수준 별 혼인표의 비대칭성으로 살펴본 남녀불평등지수)

  • 이명진
    • Korea journal of population studies
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    • v.25 no.1
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    • pp.33-50
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    • 2002
  • This study examines cross-national patterns of asymmetry of marriage tables with respect to educational level and tries to measure the degree of gender inequality across nations. A Primary assumption of the study is that gender inequality inhibits symmetric marriage between men and women. As men and women differ more in status, the rate of symmetric marriage between them declines thus producing asymmetric marriage with respect to social status. More specifically, the main object of the study is to develop statistical models and index with which to assess the patterns and degree of asymmetric marriage. Additionally, it is intended to assess the appropriateness of several theoretical perspectives for explaining these variations identified by the statistical models. Two most important such perspectives are industrialism and theory of politics and culture. To answer these questions, this study relies on twenty-seven marriage tables with respect to educational level, some from published tables, and some extracted from other sources. The main findings of the study are: (1) compared to less industrialized countries, more industrialized countries have lower degrees of asymmetric marriage(gender inequality) with respect to educational level, and (2) other things being equal, differences in politics and culture seem to have the some impact on marriage pattern; for instance, social democracy and state socialism reduce the degree of asymmetric marriage while the high emphasis on gender-based hierarchy in Asian countries seems to increase it In short, these results suggest a weaker or modified version of industrialists That is, while with economic growth most nations show a decline in the degrees of asymmetric marriage with respect to social status, for some nations the degrees of asymmetric marriage are affected by their specific politics or cultures.

A Study on Interaction Between Pain Scale and Disability Index Owing to Gait Pattern (정상인들의 걸음형태에 따른 요통정도와 장애지수와의 관련성 조사)

  • Kwon, Hyeok-Soo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.10 no.1
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    • pp.103-116
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    • 2004
  • The purpose of this study was to investigate between low back pain scale and disability index owing to gait pattern. For the period of February 1 to February 29, 2004, we had conducted a questionnaire and direct interview with 100 persons lived in Daejeon. The result were as follows: 1. The stride length of experimental group. the male was $49.9{\pm}12.9cm$. the female $45.7{\pm}12.9cm$ and the width of feet, the male was $13.5{\pm}5.7cm$, the female $12.2{\pm}4.8cm$. 2. The Fick angle of all subjects was showed in external disposition, the left angle showed in asymmetry, the male was $11.0{\pm}5.7^{\circ}$, the female $8.5{\pm}1.3^{\circ}$. 3. The foot arch was similar to sex as a weight bearing and non-weight bearing, the male was $1.3{\pm}0.8cm$, the female $1.3{\pm}0.9cm$. 4. The impedimental index according to back pain grade, men was a lower than women, the male was $5.7{\pm}6.9$ and the female $7.2{\pm}5.3$. 5. The relation to difference between foot arch and disability index according to back pain grade as a weight bearing and non-weight bearing, the higher foot arch, the higher back pain grade was statistically significance(p<.05). 6. The relation between width of feet and disability index according to back pain grade, the wider width of feet, the higher back pain grade was statistically significance(p<.01). 7. The relation between stride length and disability index according to back pain grade, the wider stride length, the higher back pain grade was statistically significance(p<.05).

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Power extraction efficiency and lasing wavelength distribution of index-coupled DEB lasers above-threshold for various facet reflectivity combinations (문턱 전류 이상에서 양 단면 반사율 조합에 따른 index-coupled DFB 레이저의 파워 추출 효율과 발진 파장 분포)

  • 김상택;김부균
    • Korean Journal of Optics and Photonics
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    • v.14 no.4
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    • pp.413-422
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    • 2003
  • We have calculated the power extraction efficiency and the lasing wavelength distribution of index-coupled DFB lasers at threshold for various kL and facet reflectivity combinations, and compared with those above-threshold. The power extraction efficiency increases as the asymmetry of the facet reflectivities increases. The power extraction efficiency above-threshold is slightly larger than that at threshold. Since the relative photon density around the center region increases as kL increases, the power extraction efficiency decreases. The uniformity of the distribution of lasing wavelength over the stop band increases due to the relief of mode degeneracy as the asymmetry of the facet reflectivities increases. In the case of AR-HR combination, the lasing wavelength distributions at threshold are similar to those above-threshold. However, in the case of AR-AR combination, the lasing wavelength at threshold is concentrated on both edges of the stop band, while it is concentrated only on the longer wavelength edge above-threshold. As kL increases, the range of the lasing wavelength distribution increases due to the increase of the stop band. The effect of AR reflectivity on the power extraction and the lasing wavelength distribution is very weak.

Evaluating LIMU System Quality with Interval Evidence and Input Uncertainty

  • Xiangyi Zhou;Zhijie Zhou;Xiaoxia Han;Zhichao Ming;Yanshan Bian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.11
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    • pp.2945-2965
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    • 2023
  • The laser inertial measurement unit is a precision device widely used in rocket navigation system and other equipment, and its quality is directly related to navigation accuracy. In the quality evaluation of laser inertial measurement unit, there is inevitably uncertainty in the index input information. First, the input numerical information is in interval form. Second, the index input grade and the quality evaluation result grade are given according to different national standards. So, it is a key step to transform the interval information input by the index into the data form consistent with the evaluation result grade. In the case of uncertain input, this paper puts forward a method based on probability distribution to solve the problem of asymmetry between the reference grade given by the index and the evaluation result grade when evaluating the quality of laser inertial measurement unit. By mapping the numerical relationship between the designated reference level and the evaluation reference level of the index information under different distributions, the index evidence symmetrical with the evaluation reference level is given. After the uncertain input information is transformed into evidence of interval degree distribution by this method, the information fusion of interval degree distribution evidence is carried out by interval evidential reasoning algorithm, and the evaluation result is obtained by projection covariance matrix adaptive evolution strategy optimization. Taking a five-meter redundant laser inertial measurement unit as an example, the applicability and effectiveness of this method are verified.

Clonal Variation of Flowering in Pinus thunbergii Seed Orchard (해송 채종원(採種園)에서 개화특성(開花特性)의 클론 변이(變異))

  • Han, Sang-Urk;Choi, Wan-Yong;Chang, Kyong-Hwan;Kim, Tae-Su;Song, Jeong-Ho
    • Journal of Korean Society of Forest Science
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    • v.90 no.6
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    • pp.717-724
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    • 2001
  • This study was conducted in an attempt to quantify some traits that may be involved in the reproductive process of Pinus thunbergii. During the past 6 years (1995-2000), we surveyed flowering patterns of 60 P. thunbergii clones in a seed orchard which was established in Anmyon-do, 1979. From this survey, we estimated clonal contributions of male and female flowers and sexual asymmetry. Among 60 clones, 18 clones (30%) accounted for 0.37 (1999)~0.46 (1995) of clonal contribution in female flowers and 0.44 (1999)~0.57 (1995) of clonal contribution in male flowers. As compared with the previous reports in other pine species, more clones made contributions to reproductive process in P. thunbergii seed orchard. The relative effective population numbers for females (v♀) varied from 0.59 (1995) to 0.91 (1999) and those for males ( v♂) were between 0.56 (1995) and 0.83 (1998) at gamete level. This showed that the female gametes effectively contribute to the reproductive process more than did the male gametes. The relative effective population numbers at clonal level ($v_b$) were in the range of 0.72 (1995) and 0.93 (1999). More than 73% of the total clones showed values of 0.4~0.6 ($0.5{\pm}0.1$) in maleness index. The values averaged over all the clones were temporally variable with the range of 73% in 1996 and 100% in 2000. The degree of sexual asymmetry ($A_s$) ranged from 0.09 to 0.26. These values were relatively low when compared with those of other trees, suggesting that P. thunbergii seed orchard remains a high level of homogeneity in the number of male and female. All of the various types of effective population numbers were positively correlated with each other while they were negatively correlated with the degree of sexual asymmetry.

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Early Results of the Sternocostal Elevation for Pectus Excavatum (Sternocostal elavation술의 누두흉 교정효과)

  • An, Byeong-Hui;Seon, Hyeon
    • Journal of Chest Surgery
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    • v.25 no.6
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    • pp.621-629
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    • 1992
  • Thirteen sternocosal elevations for pectus excavatum were performed on twelve patients between Jan 1989 and Sep. 1991. Eleven among the twleve patients were male. The subjects ranged in age from 2 years to 20 years, with a mean age of 8.33 years[SD=4.80 years], Eleven patients were below 15 years. The early postoperative evaluation by Humphreys` criteria except keloid formation was excellent in all the patients. The lower vertebral index[LVI], configuration index[CI], and upper vertebral index[UVI] were measured on the lateral chest roentgenogram. The LVI and CI improved significantly from 0.31$\pm$0.06 and 1.14$\pm$0.06 preoperatively to 0.25$\pm$0.03 and 0.78$\pm$1.10 postoperatively. The degrees of depression, flatness, and asymmetry and funnel index were measured at the most deformed portion on the computed tomgram performed pre- and postoperatively. The degrees of depression and funnel index improved significantly from 3.32$\pm$0.73 and 5.77$\pm$1. 54 preoperatively to 1.85$\pm$0.14 and 2.96$\pm$0.43 postoperatively, There was no significant change in the degree of flatness however, Six postoperative morbidities occurred in five patients Three were superficial wound infection, two hemopneumothorax, and one reoeration, Reoperation was performed due to forward displacement of the distal sternum below the posterior sternotomy, The findings of this study suggest that the sternocostal elevation is an excellent primary method for the pectus excavatum of children and young adolescents.

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A STUDY ON THE SIZE OF THE DECIDUOUS TEETH (유치의 치아크기에 관한 연구)

  • Baik, Byeong-Ju;Jeon, So-Hee;Kim, Jae-Gon;Kim, Young-Sin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.3
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    • pp.382-388
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    • 2002
  • In the present study, crown diameters and their sexual differences in deciduous teeth were investigated in children of Chon-ju city, Korea. Plaster casts of the deciduous dentitions obtained from 50 boys and 50 girls were examined. Mesiodistal and buccolingual crown diameters were measured using a digital caliper(0.01mm) according to the definitions of Seipel and Moorees et al. These measurements were performed three times, and intra-observer measurement errors were calculated by the single determination method. The crown index, module and area were calculated in order to provide a comparison of crown proportions. The results obtained were summarized as follows; 1. The mean values of intra-observer measurement errors were 0.255mm and are unlikely to have influenced the statistical analysis. 2. The mean values of mesiodistal and buccolingual crown diameters examined were larger in boys than girls. 3. The mean coefficient of variation was 5.6 in the deciduous dentition. There were a trend for the primary second molar to be the least variable in size of all teeth both in boys and girls. 4. Fluctuating asymmetry is the difference between left and right antimeres in individuals. Primary second molars were less asymmetrical than primary first molars in both dimensions. 5. In maxillary teeth, Crown index is larger in boys than in girls. In contrast, in mandibular teeth, except primary canine, it is larger in girls than in boys. Crown module is larger in boys than in girls and increased progressively from primary first incisor to primary second molar. Crown area is consistently larger in boys than in girls. The minimum crown area is mandibular primary incisor and maximum crown area is maxillary primary second molar.

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Damage detection using the improved Kullback-Leibler divergence

  • Tian, Shaohua;Chen, Xuefeng;Yang, Zhibo;He, Zhengjia;Zhang, Xingwu
    • Structural Engineering and Mechanics
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    • v.48 no.3
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    • pp.291-308
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    • 2013
  • Structural health monitoring is crucial to maintain the structural performance safely. Moreover, the Kullback-Leibler divergence (KLD) is applied usually to asset the similarity between different probability density functions in the pattern recognition. In this study, the KLD is employed to detect the damage. However the asymmetry of the KLD is a shortcoming for the damage detection, to overcoming this shortcoming, two other divergences and one statistic distribution are proposed. Then the damage identification by the KLD and its three descriptions from the symmetric point of view is investigated. In order to improve the reliability and accuracy of the four divergences, the gapped smoothing method (GSM) is adopted. On the basis of the damage index approach, the new damage index (DI) for detect damage more accurately based on the four divergences is developed. In the last, the grey relational coefficient and hypothesis test (GRCHT) is utilized to obtain the more precise damage identification results. Finally, a clear remarkable improvement can be observed. To demonstrate the feasibility and accuracy of the proposed method, examples of an isotropic beam with different damage scenarios are employed so as to check the present approaches numerically. The final results show that the developed approach successfully located the damaged region in all cases effect and accurately.