• Title/Summary/Keyword: statistical variations

Search Result 490, Processing Time 0.03 seconds

An adaptive bandwidth allocation for the two-layer VBR video transmission in ATM networks (ATM망에서 2계층 VBR 비디오 전송을 위한 적응적인 대역할당)

  • 이동은;이청훈;이팔진;김영선;김영천
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.8
    • /
    • pp.1928-1936
    • /
    • 1996
  • In this paper, we propose an adaptive bandwidth allocation algorithm for the transmission of VBR video through ATM Networks. In order to evaluate the required bandwidth for the VBR video, the characteristics of the compressed VBR video generated by the two-layered coder are analyzed with variations in the number of GOP(N), quantizer scale(q), and the number of low-frequency DCT coefficients(.betha.). The two-layer coder which is used to separate from the number of DCT coefficients is designed to transmit the VBR video efficiently. The compressed data generated by the two-layer coder are splitted into the high priority and low priority cells. If congestion is occurred in ATM networks, the minimum image quality is maintained by the high priority cells. The required bandwidth for VBR video is estimated with a prediction algorithm using the scene anframe correlations as well as the statistical properties of the VBR video sources. Strong correlation among the adjacent slices in a frame represents by the scene correlation andstrong correlation among the frames is represented by the frame correlation. The performance of the bandwidth allocation scheme proposed is evaluated in terms of the bandwith utilization, cell loss rate, and SNR with variations in q, n, .betha.. Simulation rewsults shown that the proposed scheme is superior to the conventional methods.

  • PDF

THE STUDY ON THE TOPOGRAPHIC VARIATIONS OF FACIAL SKIN IN KOREAN ADULT FEMALES

  • Cho, Joon-Hwan;Ju-An. Yun;Ha, Jae-Hyon;Cho, Youn-Ki
    • Proceedings of the SCSK Conference
    • /
    • 2003.09b
    • /
    • pp.424-437
    • /
    • 2003
  • This study was observed the variations in skin color, hydration, sebum content according to age groups at the forehead, both cheeks, and chin in 154 healthy Korean women subjects with aged 30 to 59. We selected four face sites (forehead, right cheek, left cheek, and chin) and measured with chromameter, corneometer, and sebumeter. All statistical analysis was performed on the computer software package SPSS 8.0. There was no significant difference of lightness between facial four regions in age groups but lightness showed to tend to age-related decrease on each regions. Redness and yellowness showed the highest values on chin and forehead respectively but there was no tendency to steady changes according to age variation. Both cheeks showed the highest hydration level and the lowest sebum content compared with forehead and chin in all age groups and there was tendency to age-related changes of sebum content on both cheeks. So we concluded there was decreasing tendency in lightness and sebum content according to the increase of age and there was no age-related change of skin hydration level at least in facial skin.(omitted)

  • PDF

Morning-afternoon asymmetry of geosynchronous magnetic field variations during geomagnetic sudden commencements

  • Park, Jong-Sun;Kim, Khan-Hyuk;Sung, Suk-Kyung;Lee, Dong-Hun
    • Bulletin of the Korean Space Science Society
    • /
    • 2010.04a
    • /
    • pp.40.2-40.2
    • /
    • 2010
  • It has been reported that geosynchronous magnetopause crossings are more frequently observed in the prenoon sector than in the postnoon sector, indicating a dawn-dusk magnetopause asymmetry during extreme solar wind conditions. Motivated by these observations, we investigate geosynchronous magnetic field variations normalized to SYM-H when sudden commencements (SC) are observed on the ground. From a statistical analysis of the geosynchronous magnetic field responses to SC events from 1997 to 2006, we found that the normalized SC amplitude at geosynchronous orbit is larger in the morning sector than in the afternoon sector. In order to examine if this morning-afternoon asymmetry at geosynchronous orbit occurs only during disturbed geomagnetic conditions, we compared the geosynchronous magnetic field strength obtained in the morning and afternoon during undisturbed intervals (Kp < 3). We found that the asymmetry appears under undisturbed geomagnetic conditions and it is not due to solar wind aberration. This indicates that the morning-afternoon asymmetry was not strongly affected by changes in solar wind condition. Using solar wind data, we discuss what causes the morning-afternoon asymmetry at geosynchronous orbit.

  • PDF

Exploration of Community Risk Factors for COVID-19 Incidence in Korea (코로나19 발생의 지역사회 위험요인 분석)

  • Sim, Boram;Park, Myung-Bae
    • Health Policy and Management
    • /
    • v.32 no.1
    • /
    • pp.45-52
    • /
    • 2022
  • Background: There are regional variations in the incidence of coronavirus disease 2019 (COVID-19), which means that some regions are more exposed to the risk of COVID-19 than others. Therefore, this study aims to investigate regional variations in the incidence of COVID-19 in Korea and identify risk factors associated with the incidence of COVID-19 using community-level data. Methods: This study was conducted at the districts (si·gun·gu) level in Korea. Data of COVID-19 incidence by districts were collected from the official website of each province. Data was also obtained from the Korean Statistical Information Service and the Community Health Survey; socio-demographic factor, transmission pathway, healthcare resource, and factor in response to COVID-19. Community risk factors that drive the incidence of COVID-19 were selected using a least absolute shrinkage and selection operator regression. Results: As of June 2021, the incidence of COVID-19 differed by more than 80 times between districts. Among the candidate factors, sex ratio, population aged 20-29, local financial independence, population density, diabetes prevalence, and failure to comply with the quarantine rules were significantly associated with COVID-19 incidence. Conclusion: This study suggests setting COVID-19 quarantine policy and allocating resources, considering the community risk factors. Protecting vulnerable groups should be a high priority for these policies.

Assessment and spatial variation of water quality using statistical techniques: Case study of Nakdong river, Korea

  • Kim, Shin
    • Membrane and Water Treatment
    • /
    • v.13 no.5
    • /
    • pp.245-257
    • /
    • 2022
  • Water quality characteristics and their spatial variations in the Nakdong River were statistically analyzed by multivariate techniques including correlation analysis, CA, and FA/PCA based on water quality parameters for 17 sites over 2017-2019, yielding PI values for primary factors. Site 10 indicated the highest parameter concentrations, and results of pearson's correlation analysis suggest that non-biodegradable organic matter had been distributed on the site. Five clusters were identified in order of descending pollution levels: I (Ib > Ia) > II (IIa > IIb) > III. Spatial variations started from sub-cluster Ib in which Daegu city and Geumho-river are joined. T-P, PO4-P, SS, COD, and TOC corresponded to VF 1 and 2, which were found to be principal components with strong influence on water quality. Sub-cluster Ib was strongly influenced by NO3-N and T-N compared to other clusters. According to the PIs, water quality pollution deteriorated due to non-biodegradable organic matter, nitrogen- and phosphorus-based nutrient salts in the middle and lower reaches, illustrating worsening water pollution due to inflows of anthropogenic sources on the Geumho-river, i.e., sewage and wastewater, discharged from Site 10, at which there is a concentration of urban, agricultural, and industrial areas.

A survey on consumers' purchase status of clothing products via online platforms - Focusing on the demographic characteristics of men and women in their 10s to 50s - (소비자들의 온라인 플랫폼 의류제품 구매실태 조사 - 10대~50대 남녀의 인구통계학적 특성을 중심으로 -)

  • Younghee Park
    • The Research Journal of the Costume Culture
    • /
    • v.31 no.5
    • /
    • pp.669-691
    • /
    • 2023
  • This study aims to analyze the variations in online clothing purchasing patterns based on demographic attributes and purchasing behavior. The survey subjects comprised individuals in their 10s to 50s who had prior experience with online shopping. The survey was conducted in Gyungnam from May to June 2022. A total of 397 questionnaires were analyzed using the χ2-test statistical method. The analysis of clothing purchase type based on demographic characteristics revealed differences in terms of gender, marital status, age, monthly income, and occupation. Notably, when analyzed by demographic characteristics and clothing purchase types, monthly online purchase frequency displayed significant differences in marital status, age, and occupation. Similarly, monthly purchase amounts through online platforms exhibited significant variations based on marital status, age, monthly income, and occupation. The online fashion platforms, when examined in relation to demographic characteristics and purchase types, showed significant differences across all variables. Clothing purchases by consumers seeking individuality and differentiation exhibited significant differences in age, occupation, and purchase types. Furthermore, the reasons for choosing online platforms for clothing purchases varied significantly based on age and occupation. These findings indicate diverse purchasing behaviors on online platforms influenced by demographic characteristics. These findings can be valuable for effectively segmenting the online fashion market.

The Effect of Bee Venom Acupuncture(BVA) on acute Ankle Sprain : A Randomized Controlled Trial and double blinding - Pilot study (급성 족관절 염좌에 대한 봉약침 효과-무작위대조시험, 이중맹검)

  • Song, Ho-Seub
    • Journal of Pharmacopuncture
    • /
    • v.8 no.2
    • /
    • pp.11-16
    • /
    • 2005
  • Objective : The aim of the study was to investigate the therapeutic effect of BVA in the treatment of patients with acute ankle sprain. Design : A prospective randomized double-blind study of BVA was conducted. Setting : The study was done in the Kyungwon University Seoul Hospital from August 1st, 2004 to June 15th, 2005. Patients : 30 patients diagnosed with acute ankle sprain, especially 2nd degree on the Ankle grade pain chart(AGPC) participated in the study, who were divided into two groups (A and B) randomly by a coordinator flipping a coin. Group A and B were relevant to control and BVA group respectively, of which a coordinator never informed any other participant involved. Eventually 13 of 17 in group A and 11 of 13 in Group B finished all the process of the clinical trial. Intervention : In both group A and B, The Procedure of acupuncture treatment was made similar by appearance that four acupoints such as 坵墟(GB40), 中封(LR4), 商丘(SP5), 解谿(ST41) of the injured side were selected and Normal saline aqua-acupuncture(control, as a placebo) or BVA was done and then acupuncture at 坵墟(GB40), 中封(LR4), 商丘(SP5), 解谿(ST41), 足三里(ST36), 陽陵泉(G34) of the affected side was given again. the needles were retained for 20 minutes under the infrared rays. The treatment was given daily for a week. Outcome Measures : Ankle-Hindfoot Scale (AHS) and Visual Analogue Scale(VAS) were followed by three treatments. Statistical Analysis : Analysis regarding variations in AHS and VAS is carried out by applying Mann-Whitney test and Wilcoxon signed rank test sign test with level of significance at 5%. Results : At the end of the treatment, there was significant statistical differences between the two groups in VAS and AHS as well, while at the 3rd day only a VAS showed statistical significance. In each group, both VAS and AHS showed statistical significance along with duration of treatment. Conclusions : BVA was thought to be effective alternatives for relieving symptoms of acute ankle sprain, although further study was needed on the large scale.

Effects of Bovis Calculus, Ursi Fel Aqua-acupuncture on Adjuvant Arthritis in rats (우황(牛黃).웅담(熊膽) 약침(藥鍼)이 Adjuvant 관절염(關節炎)에 미치는 영향(影響))

  • Hwang, Byeong-Tae;Kim, Hui-Cheol;Hwang, U-Jun
    • Journal of Pharmacopuncture
    • /
    • v.1 no.1
    • /
    • pp.35-52
    • /
    • 1997
  • In order to investigate experimentally that Bovis Calculus, Ursi Feli Aqua-acupuncture(BUA) have an effect on Adjuvant Arthritis in rats, the author inserted BUA at points corresponding with Chok-samni(ST36) and T'aegye(KI3), and observed an inhibitory rate of edema and pain, variations of White blood cell(WBC), Red blood cell(RBC), Hemoglobin(Hb) in blood. The author also observed the histological changes of joint tissue. The results were as follows : 1. The BUA group during the 6th and 9th were decreased with statistical significance in inhibitory rate of paw edema as compared with the control group. 2. The BUA group during the 3rd and 9th day were decreased with statistical significance in inhibitory rate of pain as compared with the control group. 3. The BUA group during the 3rd, 6th and 9th day were decreased with statistical significance in blood WBC as compared with the control group. The blood RBC and Hb didn't have statistical significance. 4. According to the histological studies, the synovial cells were necrotized at the 3rd, 6th and 9th day control group, but some synovial cells were necrotized at the 3rd day BUA group. The synovial cells of the the 6th and 9th day BUA group were recovered more than that of the 3th day group.

Assessment of Runoff and Water temperature variations under RCP Climate Change Scenario in Yongdam dam watershed, South Korea (기상 관측자료 및 RCP 기후변화 시나리오를 고려한 용담댐 유입하천의 유량 및 수온변화 전망)

  • Yi, Hye-Suk;Kim, Dong-sup;Hwang, Man-Ha;An, Kwang-Guk
    • Journal of Korean Society on Water Environment
    • /
    • v.32 no.2
    • /
    • pp.173-182
    • /
    • 2016
  • The objective of this study is to quantitatively analyze climate change effects by using statistical trends and a watershed model in the Yongdam dam watershed. The annual average air temperature was found to increase with statistical significance. In particular, greater increases were observed in autumn. Also, this study was performed to evaluate the potential climate change in the streamflow and water temperature using a watershed model (HSPF) with RCP climate change scenarios. The streamflow of Geum river showed a decrease of 5.1% and 0.2%, respectively, in the baseline data for the 2040s and 2080s. The seasonal impact of future climate change on the streamflow showed a decrease in the summer and an increase in the winter. The water temperature of Geum river showed an average increase of 0.7~1.0℃. Especially, the water temperature of Geum river showed an increase of 0.3~0.5℃ in the 2040s and 0.5~1.2℃ in the 2080s. The seasonal impact of future climate change on the water temperature showed an increase in winter and spring, with a decrease in summer. Therefore, it was determined that a statistical analysis-based meteorological and quantitative forecast of streamflow and water temperature using a watershed model is necessary to assess climate change impact and to establish plans for future water resource management.

An Analysis on Teaching of Data Collection in Elementary School Mathematics Textbooks for 3rd and 4th Grades from the Perspective of Statistical Problem Solving Education (통계적 문제해결 교육의 관점에 따른 초등학교 수학 교과서의 자료 수집 지도 방식 분석: 3~4학년군을 중심으로)

  • Tak, Byungjoo;Ko, Eun-Sung
    • Education of Primary School Mathematics
    • /
    • v.25 no.4
    • /
    • pp.329-341
    • /
    • 2022
  • Data collection is crucial to the process of statistical problem solving since it influences the quality of statistical data. However, there is little instruction on data collection in the Korean mathematics curriculum. In this study, we examined how the data were collected and how the data collection method was taught in the Korean mathematics textbooks for 3rd and 4th grades. As a result, the data appeared in these textbooks were collected by using a variety of methods, including surveys, experiments, observations, and secondary data collections. There were not enough instructions on experiments and observations, compared to surveys and secondary data collection. Additionally, as each textbook works with a distinct contents while teaching data collection, it is expected that there would be variations in the levels that students learn in relation to data collection. Based on these findings, we draw some discussion points to determine how to improve the mathematics curriculum in order to effectively teach data collection in the elementary school.