• Title/Summary/Keyword: Soft Region

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Erlang Capacity of Cellular CDMA Mobile Communication System with soft Handoff (소프트 핸드오프를 갖는 셀룰러 CDMA 이동통신 시스템의 Erlang 용랑)

    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.3A
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    • pp.334-341
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    • 2000
  • This paper presents an analysis of the capacity, the interference of adjacent cells of a CDMA cellular system, depending on the soft handoff region and log-normal shadowing. The optimum soft handoff region is chosen by using Erlang capacity. It is shown that when the soft handoff region increases, the Erlang capacity increase due to a reduction of the interference power of adjacent cells. But if the region is increased above a certain value, there is no improvement in the system’s capacity. Furthermore as the standard deviation of the log-normal shadowing's normal distribution factor increases, the soft handoff region has to be increased linearly to achieve the same Erlang capacity.

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Performance Analysis of Soft Handoff Region Ratio in CDMA System Considering System Capacity and Traffic Load (CDMA망에서 시스템 용량과 트래픽 부하의 변화를 반영한 핸드오프 영역 비율에 대한 성능분석)

  • Jung, Sung-Hwan;Hong, Jung-Wan;Lee, Sang-Cheon;Lie, Chang-Hoon
    • IE interfaces
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    • v.20 no.2
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    • pp.216-226
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    • 2007
  • In code-division multiple-access (CDMA) systems with soft handoff, mobile station (MS) within soft handoff region can use multiple radio channels and receive their signals from multiple base stations (BSs) simultaneously. In this paper, the effects of soft handoff region ratio (SHRR) on reverse link of a CDMA cellular system are analytically investigated. In order to analyze the network performance and quality of service (QoS) perceived by users more realistically, both the soft capacity increasing factor and the traffic load variation affected by SHRR are jointly considered and a two-dimensional continuous time Markov chain (CTMC) model is built. In the numerical example, it is observed that the optimal guard channel exists according the variations of the traffic load and propagation conditions when the proper value of SHRR is determined.

Effects of soft handoff region ratio on the reverse link capacity of a DS-CDMA cellular system (DS-CDMA 셀룰라 시스템의 역방향 링크에서 소프트 핸드오프 영역비율의 효과)

  • 전형구;권오준;강창언
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.11B
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    • pp.1534-1539
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    • 2001
  • In this paper, effects of soft handoff region on the reverse link capacity of a DS-CDMA cellular system are investigated. The reverse link capacity of a CDMA cellular system is calculated at a given soft handoff region ratio (SHRR) and path loss model. The results show that the reverse link capacity increases by 1 ∼ 4 channels according to the soft handoff region ratio and the path loss model. However, in the case of the path loss model having a large attenuation exponent ($\mu$ = 5) and a small shadowing standard deviation ( $\sigma$ = 6 dB), the reverse link capacity is no more increased by increasing SHRR.

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Characterizing Viscoelastic Property of Soft Tissue Over the Hip as a Risk Factor of Pressure Ulcer

  • Lim, Kitaek;Kim, Seung-su;Choi, Woochol Joseph
    • Physical Therapy Korea
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    • v.28 no.1
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    • pp.72-76
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    • 2021
  • Background: A pressure ulcer is common in soft tissue over the greater trochanter (GT) in side-lying position, and sustained tissue deformation induced by the prolonged external force is a primary cause, which can be discussed with soft tissues' viscoelastic properties (i.e., stress relaxation, creep response). Objects: Using an automated hand-held indentation device, we measured the viscoelastic properties of soft tissue over the hip area, in order to examine how the properties are affected by site with respect to the GT. Methods: Twenty participants (15 males and 5 females) who aged from 21 to 32 were participated. An automated hand-held indentation device was used to measure the stress relaxation time and creep response. Trials were acquired for three different locations with respect to the GT (i.e., right over the GT, 6 cm anterior or posterior to the GT). For each location, five trials were acquired and averaged for data analyses. Results: Soft tissues' stress relaxation time and creep response were associated with site (F = 23.98, p < 0.005; F = 24.09, p < 0.005; respectively). The stress relaxation time was greatest at posterior gluteal region (19.22 ± 2.49 ms), and followed by anterior region (15.39 ± 2.47 ms) and right over the GT (14.40 ± 3.18 ms). Similarly, creep response was greatest at posterior gluteal region (1.16 ± 0.14), and followed by anterior region (0.95 ± 0.14) and right over the GT (0.89 ± 0.18). Conclusion: Our results showed that the stress relaxation and creep were greatest at the posterior gluteal region and least at right over the GT, indicating that the gluteal soft tissue is more protective to the prolonged external force, when compared to the trochanteric soft tissue. The results suggest that a risk of pressure ulcer over the GT may decrease with slightly posteriorly rotated side-lying position.

A Study on the Relationship between the Physical Properties of Soil and the Compression Index of Soft Clay in Gyungnam Coastal Region (경남해안지역 연약점토의 토질특성과 압축지수와의 상관성에 관한 연구)

  • 장정욱;최성민;박춘식
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.4
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    • pp.282-289
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    • 2001
  • This study analyzed the relationship between the physical properties of soil and the compression index of the soft clay in Gyungnam coastal region. Tests of physical and mechanical properties of soil have been carried out under the undisturbed condition at 82 Gimhae, 18 Jinhae and 27 Geojespecimens. The result showed that Terzaghi & Peck's empirical equation of the compression index were not applicable. The compression index of soft clay in Gyungnam coastal region was correlated with the water contents, the liquid limit and the initial void ratio. Among these, the initial void ratio showed the highest correlation with the compression index of soft clay in Gyungnam coastal region and the relationship is shown in the following. (1) The compression index of soft clay in Gyungnam coastal region is represented as follows: $C_c=0.74(e_o-0.7$ (2) The relationship between compression index and the swelling index in Gyungnam coastal region is represented as follows: $C_s=(1/8-1/15)C_c$.

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Analysis of the soft handoff rate in DS-CDMA cellular systems (DS-CDMA 셀룰라 시스쳄에서의 소프트 핸드오프율에 대한 분석)

  • 조무호;김광식;조경록
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.8
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    • pp.1659-1667
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    • 1997
  • In DS-CDMA cellular systems, using the same frequency channel at the adjacent cells simultaneously makes soft handoff possible. In soft handoff, mobiles use multiple radio resources for the space diversity of signal in the overlapped region. The previous traffic models of hard handoff are not applicable to the system with soft handoff due to switching radio channels in that region. The handoff rate can be calculated by the mobility of mobiles, which is a function of the size and shape of a cell, and the speed and density of the mobiles. In this paper, we propose an analytical traffic model to study the soft handoff rate. We assume that the system uses a two-way handoff scheme for practical purposes, which connects only two cells to a mobile during soft handoff. We performed a computer simulation to confirm the accuracy of the proposed soft handoff model. The simulation results show good agreement with the analytical model.

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Erlang Capacity and Call Blocking Probability of CDMA Hierarchical Cellular Systems with Soft Handoff (소프트 핸드오프를 갖는 CDMA 계층구조 셀룰러 시스템의 Erlang 용량과 호 차단확률)

  • Seong, Bong-Hun;O, Hyeon-Seok;Han, Jae-Chung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.8
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    • pp.481-490
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    • 2000
  • This paper analyzes interference power, Erlang capacity, the number of handoff occurrences, and call blocking probability with respect to the cell radius, the soft handoff region, and the mobile's velocity in a CDMA hierarchical cellular system. The microcell cellular system has the higher Erlang capacity than the macrocell cellular system. However, the microcell cellular system, which has a high system capacity through frequency reuse has the call blocking probability higher than macrocell cellular system. Also the interference power and the call blocking probability are decreased with the operation of soft handoff. Therefore, this paper presents the optimization of soft handoff region so as to maximize system's Erlang capacity with the low the call blocking probability according to mobile's velocity in the CDMA hierarchial cellular system.

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Soft-tissue osteoma of the temple

  • Roh, Si-Gyun;Kim, Yun-Seob;Kim, Jong-Lim;Shin, Jin-Yong;Lee, Nae-Ho
    • Archives of Craniofacial Surgery
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    • v.22 no.5
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    • pp.276-279
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    • 2021
  • A 65-year-old woman presented with a solid mass on the right temporal area. The mass had grown for over 2 years without any initiating event of trauma or inflammation. Before excision, the patient went through a computed tomography scan, revealing a calcified mass without bony connection. Under general anesthesia, an excisional biopsy was performed. Microscopic examination confirmed a diagnosis of soft tissue osteoma. Soft tissue osteoma is rare, especially in the head and neck region. Osteomas in the temporal region have not been reported yet. Due to its rarity, osteoma might be misdiagnosed as another soft tissue or bone origin tumor. Its treatment of choice is simple excision. In this review, we present an unusual clinical form of soft tissue osteoma.

A Clinical Study of Soft Tissue Changes of the Midface after Mandibular Setback Surgery (하악골 후방이동시 중안면부 연조직의 변화양상에 대한 임상통계학적 연구)

  • Han, Dae-Hee;Kim, Soo-Nam;Min, Seung-Ki;Kim, Tae-Seong;Sung, Hun-Mo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.22 no.3
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    • pp.319-329
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    • 2000
  • Prediction of the soft tissue changes following hard tissue movement is very important from the esthetic view point for patients who have orthognathic surgery. There are many cephalometric analysis of facial bone and soft tissue on the lower lip and chin region but few soft tissue analysis on the midface after mandibular setback surgery. This study was performed to obtain whether the mandibular posterior movement has influence on the midface and the predictable ratio of post-operative measurement values of the soft tissue changes following mandibular setback surgery. Fifteen patients (8 males and 7 females) who had undergone mandibular setback surgery were selected and analyzed the soft tissue movement on the upper lip and the cheek region. Post-operative changes of the soft tissue measurements after mandibular surgery were examined on pre- and post-operative cephalometrics and the ratio of changes were analyzed after drawing the reference line on the face with the barium sulfate solution. The reference lines were perpendicular to the intercanthal line from infraorbital foramen and lateral canthus. The results obtained were as follows : 1. There were tendancy of anterior movement of soft tissue adjacent the nose after mandibular surgery 2. There were incerased tendancy of the amount of anterior movement from the nasal crease to the cheek region. 3. The amount of anterior movement of the soft tissue was larger below the palatal plane compared with above the palatal plane in the cheek region. 4. The upper lip length was increased and moved posterior direction after mandibular setback surgery 5. The lower lip was moved posterior direction by posterior movement of the mandibular structure 6. Soft tissue of the midface around the nose moved anterior direction after mandibular setback surgery but there was no correlation between the amount of mandibular setback and the amount of the soft tissue changes

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Soft-tissue Sarcomas in the Asia-Pacific Region: A Systematic Review

  • Ngan, Roger;Wang, Edward;Porter, David;Desai, Jayesh;Prayogo, Nugroho;Devi, Beena;Quek, Richard
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6821-6832
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    • 2013
  • Background: Soft-tissue sarcomas require tailored and multidisciplinary treatment and management. However, little is known about how sarcomas are treated and managed throughout the Asia-Pacific region. Materials and Methods: MEDLINE was systematically searched using prespecified criteria. Publications (previous 10 years) that reported tumour characteristics, treatment patterns, survival outcomes, and/or safety outcomes of patients with soft-tissue sarcoma were selected. Exclusion criteria were studies of patients <18 years of age; ${\leq}10$ patients; countries other than Australia, Hong Kong, Indonesia, Korea, Malaysia, New Zealand, Philippines, Singapore, Taiwan, or Thailand; >20% benign tumours; sarcomas located in bones or joints; gastrointestinal stromal tumour; Kaposi's sarcoma; or not reporting relevant outcomes. Results: Of the 1,822 publications retrieved, 35 (32 studies) were included. Nearly all patients (98%, 1,992/2,024; 31 studies) were treated with surgery, and more studies used adjuvant radiotherapy than chemotherapy (24 vs 17 studies). Survival outcomes and recurrence rates varied among the studies because of the different histotypes, sites, and disease stages assessed. Only 5 studies reported safety findings. Conclusions: These findings highlight the lack of specific data available about soft-tissue sarcomas in the Asia-Pacific region. Better efforts to understand how the sarcoma is managed and treated will help improve patient outcomes in the region.