• Title/Summary/Keyword: Multi-dimensional index

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Performance Evaluation of FC-MMA and RMMA Algorithm for Adaptive Equalization in 2-dimensional QAM Signals (2차원 QAM 신호에서 적응 등화를 위한 FC-MMA와 RMMA 알고리즘의 성능 평가)

  • Lim, Seung-Gag;Kang, Dae-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.5
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    • pp.91-97
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    • 2016
  • This paper evaluates the equalization algorithm of FC-MMA (Fast Convergence-Multi Modulus Algorithm) and RMMA (Region based Multi Modulus Algorithm) for the compensation of intersymbol interference which is due to the distortion of communication channel. In order to obtain the error signal for adaptive equalization, the FC-MMA use the modified dispersion constant considering the number of signal symbol, the RMMA separates the 4 region which every symbol points are located, then reduce the symbol point based on this region into constant modulus symbol point. By applying the different principle in order to get the error signal for the updating the tap coefficient of adaptive equalizer, it has the different equalization performance by these error signal. The computer simulation was performed in order to compare the different equalization performance in this paper. The performance index includes the output signal constellation, the residual isi and maximum distortion that is for the convergence characteristics, the SER. As a result of computer simulation, RMMA has more good performance in the residual isi, maximum distortion after in steady state and SER performance than FC-MMA, but not in convergence speed to reach the steady state.

Modeling the Effect of Intake Depth on the Thermal Stratification and Outflow Water Temperature of Hapcheon Reservoir (취수 수심이 합천호의 수온성층과 방류 수온에 미치는 영향 모델링)

  • Sun-A Chong;Hye-Ji Kim;Hye-Suk Yi
    • Journal of Environmental Impact Assessment
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    • v.32 no.6
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    • pp.473-487
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    • 2023
  • Korea's multi-purpose dams, which were constructed in the 1970s and 1980s, have a single outlet located near the bottom for hydropower generation. Problems such as freezing damage to crops due to cold water discharge and an increase the foggy days have been raised downstream of some dams. In this study, we analyzed the effect of water intake depth on the reservoir's water temperature stratification structure and outflow temperature targeting Hapcheon Reservoir, where hypolimnetic withdrawal is drawn via a fixed depth outlet. Using AEM3D, a three-dimensional hydrodynamic water quality model, the vertical water temperature distribution of Hapcheon Reservoir was reproduced and the seasonal water temperature stratification structure was analyzed. Simulation periods were wet and dry year to compare and analyze changes in water temperature stratification according to hydrological conditions. In addition, by applying the intake depth change scenario, the effect of water intake depth on the thermal structure was analyzed. As a result of the simulation, it was analyzed that if the hypolimnetic withdrawal is changed to epilimnetic withdrawal, the formation location of the thermocline will decrease by 6.5 m in the wet year and 6.8 m in the dry year, resulting in a shallower water depth. Additionally, the water stability indices, Schmidt Stability Index (SSI) and Buoyancy frequency (N2), were found to increase, resulting in an increase in thermal stratification strength. Changing higher withdrawal elevations, the annual average discharge water temperature increases by 3.5℃ in the wet year and by 5.0℃ in the dry year, which reduces the influence of the downstream river. However, the volume of the low-water temperature layer and the strength of the water temperature stratification within the lake increase, so the water intake depth is a major factor in dam operation for future water quality management.

The Effects of Socioeconomic Deprivation on Public Library Book Circulation: A Community-level Study (지역사회 사회경제적 박탈이 공공도서관 대출 책수에 미치는 영향)

  • Lee, Jongwook;Kang, Woojin;Lee, Myeong
    • Journal of the Korean Society for Library and Information Science
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    • v.55 no.4
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    • pp.219-243
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    • 2021
  • This study analyzes the effects of community-level socioeconomic deprivations (SED) on public libraries' book circulation in the Seoul metropolitan area. The study design draws upon the theory of local information landscapes, which explains the relationship between community characteristics and information behavior. Using four-year (2015-2018) open government and public library circulation data, we constructed a socioeconomic deprivation index by adjusting a multi-dimensional deprivation index and generated other variables. Multi-level robust linear regression models were used to examine the relationship between SED and public library circulation. In addition, we tested the moderating effects of the library collection size and the number of libraries per unit area, respectively, on library circulation. The results show that there is a significant negative relationship between socioeconomic deprivation and library circulation rate. Also, we found that the size of the library collection negatively moderates the effects of SED in areas with a large number of books, and the number of libraries per unit area was positvely related to the library book circulation, not moderating the effects of SED. These findings suggest that public libraries and policymakers should consider community characteristics in designing strategic plans for public libraries.

Wave propagation simulation and its wavelet package analysis for debonding detection of circular CFST members

  • Xu, Bin;Chen, Hongbing;Xia, Song
    • Smart Structures and Systems
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    • v.19 no.2
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    • pp.181-194
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    • 2017
  • In order to investigate the interface debonding defects detection mechanism between steel tube and concrete core of concrete-filled steel tubes (CFSTs), multi-physical fields coupling finite element models constituted of a surface mounted Piezoceramic Lead Zirconate Titanate (PZT) actuator, an embedded PZT sensor and a circular cross section of CFST column are established. The stress wave initiation and propagation induced by the PZT actuator under sinusoidal and sweep frequency excitations are simulated with a two dimensional (2D) plain strain analysis and the difference of stress wave fields close to the interface debonding defect and within the cross section of the CFST members without and with debonding defects are compared in time domain. The linearity and stability of the embedded PZT response under sinusoidal signals with different frequencies and amplitudes are validated. The relationship between the amplitudes of stress wave and the measurement distances in a healthy CFST cross section is also studied. Meanwhile, the responses of PZT sensor under both sinusoidal and sweep frequency excitations are compared and the influence of debonding defect depth and length on the output voltage is also illustrated. The results show the output voltage signal amplitude and head wave arriving time are affected significantly by debonding defects. Moreover, the measurement of PZT sensor is sensitive to the initiation of interface debonding defects. Furthermore, wavelet packet analysis on the voltage signal under sweep frequency excitations is carried out and a normalized wavelet packet energy index (NWPEI) is defined to identify the interfacial debonding. The value of NWPEI attenuates with the increase in the dimension of debonding defects. The results help understand the debonding defects detection mechanism for circular CFST members with PZT technique.

Quantitative and Qualitative Gradient of Pain Experience, Sleep Quality and Psychological Distress in Patients with Different Phenotypes of Temporomandibular Disorders

  • Choi, Hee Hun;Kim, Hye-Kyoung;Kim, Mee-Eun
    • Journal of Oral Medicine and Pain
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    • v.45 no.3
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    • pp.56-64
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    • 2020
  • Purpose: Temporomandibular disorders (TMD) is a mosaic of clinical signs and symptoms that can be regarded as a set of phenotypes that are affected by various factors including pain sensitivity, pain disability, sleep and psychological functioning. The aims of this study were to evaluate association of pain experience, sleep quality and psychological distress with different phenotypes of TMD patients. Methods: This retrospective study included a cohort (n=1,858; 63.8% for female, mean age=34.9±15.9 years) of patients with TMD. A set of self-administered questionnaires concerning pain interference (Brief Pain Inventory), pain disability (Graded Chronic Pain Scale), sleep quality (Pittsburg Sleep Questionnaire Index), psychological distress (Symptom Checklist-90 revised), and pain catastrophizing (Pain Catastrophizing Scale) were administered to all participants at the first consultation. All TMD patients were classified into four groups including TMD with internal derangement without pain (TMD_ID, n=370), TMD with joint pain (TMD_J, n=571), TMD with muscle pain (TMD_M, n=541) and TMD with muscle-joint combined pain (TMD_MJ, n=376). Results: The female ratio was particularly high in the group with TMD_MJ (p=0.001). The patients with muscle pain and both muscle and joint pain had longer symptom duration (p=0.004) and presented significantly higher scores in pain experience (p<0.001), subjective sleep quality (p<0.001), pain catastrophizing (p<0.001) and psychological distress (p<0.05) except for paranoid-ideation than the groups with only joint problems. Conclusions: The results of this study highlight the importance of multi-dimensional approach that consider pain disability, sleep quality, and psychological functioning in the management of TMD with muscle component. This study would contribute to a better understanding of interaction between heterogeneous TMD and multiple risk factors in order to build tailored treatment based on different phenotypes.

A Study on the Optimization of Silicon Antiresonant Reflecting Optical Waveguides (ARROW) for Integrated Optical Sensor Applications (집적광학 센서 응용에 적합한 실리콘 비공진 반사형 광도파로 최적화에 관한 연구)

  • Jung, Hong-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.5
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    • pp.153-160
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    • 2010
  • We optimized the Si(substrate)/$SiO_2$(cladding)/$Si_3N_4$(antiresonant cladding)/$SiO_2$(core)/air multi-layers rib-optical waveguides of antiresonant reflecting optical waveguide (ARROW) for integrated optical biosensor structure utilizing beam propagation method (BPM). Thickness of anti-resonant cladding was derived to minimize the propagation loss and leaky field mode deeply related with evanescent mode was theoretically derived. Depth, width, refractive index and cladding thickness of anti-resonant cladding were numerically calculated into 2.3${\mu}m$, 5${\mu}m$, 1.488, and 0.11${\mu}m$ respectively to minimize propagation loss using the BPM simulation tool. Finally one- and two-dimensional propagation characteristics of ARROW was confirmed.

A Concurrency Control Method for Non-blocking Search Operation based on R-tree (논 블록킹 검색연산을 위한 R-tree 기반의 동시성 제어 기법)

  • Kim, Myung-Keun;Bae, Hae-Young
    • The KIPS Transactions:PartD
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    • v.11D no.4
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    • pp.809-822
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    • 2004
  • In this paper, we propose a concurrency control algorithm based on R-tree for spatial database management system. The previous proposed algorithms can't prevent problem that search operation is to be blocking during update operations. In case of multidimensional indexes like R-tree, locking of update operations may be locked to several nodes, and splitting of nodes have to lock a splitting node for a long time. Therefore search operations have to waiting a long time until update operations unlock. In this paper we propose new algorithms for lock-free search operation. First, we develop a new technique using a linked-list technique on the node. The linked-list enable lock-free search when search operations search a node. Next, we propose a new technique using a version technique. The version technique enable lock-free search on the node that update operations is to be splitting.

Kinematic Analysis of Dynamic Stability Toward the Pelvis-spine Distortion during Running (달리기 시 체간의 골반-척추구조변형이 동적안정성에 미치는 연구)

  • Park, Gu-Tae;Yoo, Kyoung-Seok
    • Korean Journal of Applied Biomechanics
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    • v.23 no.4
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    • pp.369-376
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    • 2013
  • The purposes of this study were to assess dynamic stability toward pelvis-spine column distortion during running and to compare the typical three-dimensional angular kinematics of the trunk motion; cervical, thoracic, lumbar segment spine and the pelvis from the multi-segmental spine model between exercise group and non-exercise group. Subjects were recruited as exercise healthy women on regular basis (group A, n=10) and non-exercise idiopathic scoliosis women (group B, n=10). Data was collected by using a vicon motion capture system (MX-T40, UK). The pelvis, spine segments column and lower limbs analysiaed through the 3D kinematic angular ROM pattern. There were significant differences in the time-space variables, the rotation motion of knee joint in lower limbs and the pelvis variables; obliquity in side bending, inter/outer rotation in twisting during running leg movement. There were significant differences in the spinal column that is lower-lumbar, upper-lumbar, upper-thoracic, mid-upper thoracic, mid-lower thoracic, lower thoracic and cervical spine at inclination, lateral bending and twist rotation between group A and group B (<.05, <.01 and <.001). As a results, group B had more restrictive motion than group A in the spinal column and leg movement behaved like a 'shock absorber". And the number of asymmetry index (AI) showed that group B was much lager unbalance than group A. In conclusion, non-exercise group was known to much more influence the dynamic stability of equilibrium for bilateral balance. These finding suggested that dynamic stability aimed at increasing balance of the trunk ROM must involve methods and strategies intended to reduce left/right asymmetry and the exercise injury.

A Genetic Analysis of Taoyuan Pig and Its Phylogenetic Relationship to Eurasian Pig Breeds

  • Li, Kuan-Yi;Li, Kuang-Ti;Cheng, Chun-Chun;Chen, Chia-Hsuan;Hung, Chien-Yi;Ju, Yu-Ten
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.4
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    • pp.457-466
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    • 2015
  • Taoyuan pig is a native Taiwan breed. According to the historical record, the breed was first introduced to Taiwan from Guangdong province, Southern China, around 1877. The breed played an important role in Taiwan's early swine industry. It was classified as an indigenous breed in 1986. After 1987, a conserved population of Taoyuan pig was collected and reared in isolation. In this study, mitochondrial DNA sequences and 18 microsatellite markers were used to investigate maternal lineage and genetic diversity within the Taoyuan pig population. Population differentiation among Taoyuan, Asian type, and European type pig breeds was also evaluated using differentiation indices. Only one D-loop haplotype of the Taoyuan pig was found. It clustered with Lower Changjiang River Basin and Central China Type pig breeds. Based on the polymorphism of microsatellite markers, a positive fixation index value ($F_{IS}$) indicates that the conserved Taoyuan population suffers from inbreeding. In addition, high $F_{ST}$ values (>0.2105) were obtained, revealing high differentiation among these breeds. Non-metric multi-dimensional scaling showed a clear geometric structure among 7 breeds. Together these results indicate that maternally Taoyuan pig originated in the Lower Changjiang River Basin and Central China; however, since being introduced to Taiwan differentiation has occurred. In addition, Taoyuan pig has lost genetic diversity in both its mitochondrial and nuclear genomes.

Mother-Child Emotional Availability Mediating the Effects of Maternal Psychological Well-being and Child's Cognitive Competence on Child Behavior Problems

  • Kang, Min-Ju
    • International Journal of Human Ecology
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    • v.12 no.2
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    • pp.95-107
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    • 2011
  • Recent intervention studies document that mother-child dyads with higher levels of Emotional Availability (EA) report fewer child behavior problems than dyads with lower EA. This study examines possible mechanisms that lead to this result by looking at the parent-child micro-system as a whole, with multi-dimensional relationships that include individual differences in the child's cognitive level, parental stress and parent-child interaction. A total 67 children ($1{\frac{1}{2}}$ to $5\;{\frac{1}{2}}$ years of age) and their mothers were videotaped during 30-min play interactions. Interactions were coded using the Emotional Availability (EA) Scales (Biringen, Robinson, & Emde, 1998). Mothers completed Parenting Stress Index-Short Form, Child Behavior Checklist/$1\;{\frac{1}{2}}$ - 5, and the Ages Stages Questionnaire. The findings showed that mothers with higher levels of parenting stress were more likely to be intrusive, hostile, insensitive, and had a tendency to do less structuring in play. The children of stressed and depressed mothers demonstrated less involvement and responsiveness towards their mothers. Children who have higher dyadic EA scores experienced fewer externalizing and internalizing problems. SEM analyses results showed a mediation effect of EA on the association between maternal psychological well-being and child behavior problems. Fewer deficits in child communication skills and problem solving skills that were related with lower parenting stress and depression were associated with higher maternal non-intrusiveness. Higher non-intrusiveness was related to less internalizing and externalizing problems that indicated the indirect effect of child cognitive competence. Possible interpretations and implications of the study findings are discussed.