• Title/Summary/Keyword: Frequency Planning

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Frequency Planning and Interference Rejection with Co-Channel Dual-Polarization Technique in B-WLL Applications (코채널 이중편파 기술을 적용한 B-WLL 의 주파수 배치 및 채널간섭 제거기에 대한 연구)

  • 이재원;서경환;정한욱
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.821-824
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    • 1999
  • In this article, as a way of pursuing high spectral efficiency and flexible cell planning, co-channel dual-polarization techniques are suggested for B-WLL applications. It provides a double down stream capacity compared with conventional scheme and also makes some flexibility in cell planning. In order to implement co-channel B-WLL system, some frequency plans, interference cancellation methods, and system block diagrams are presented here.

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WORKFORCE INFORMATION DATABASE AND RFID TECHNOLOGY TO TRACK AND MANAGE WORKFORCE INFORMATION

  • Yong-Woo Kim;Sang-Chul Kim;Chan-Jeong Park
    • International conference on construction engineering and project management
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    • 2009.05a
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    • pp.1094-1099
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    • 2009
  • Workforce information is important in production planning because production planning requires matching a production unit's capacity to loads of assignments. However, tracking and managing workforce information such as skills and accident history is not an easy job. This paper describes a prototype database system for a workforce database system that employs RFID technology. This system tracks daily workforce production capacity on sites. A pilot project is described to explore the benefits and possibility of using radio-frequency identification (RFID) to track and manage workforce information, and is followed by the results of a survey to identify benefits. In addition to the survey identifying the benefits of the database system, the paper also presents a list of challenges through a series of interviews.

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Performance of Frequency Planning and Channel Allocation Algorithm for Unified Inter-Cell Interference Avoidance and Cancellation in OFDMA Cellular Systems (OFDMA 셀룰러 시스템에서 셀 간 간섭 회피 및 제거 기법을 적용한 주파수 설계와 채널 할당 알고리즘의 성능)

  • Lee, Jae-Hoon;Kim, Dong-Woo;Lee, Hee-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.2A
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    • pp.99-106
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    • 2009
  • In this paper, we propose UCA algorithms that are applied to the unified inter-cell interference mitigation through frequency plannings in OFDMA cellular systems. Under three frequency plannings, UCA algorithms allocate frequency channels to UEs(User Equipments). Proposed UCA algorithms require the information of received signal power from home sector and neighbor sectors respectively. We compare all possible combinations of UCA algorithms and frequency plannings through compute simulation. A primary performance measure is the low 5th percentile of SINR at UEs. The proposed UCA algorithms can avoid the interference to neighbor cells by allocating relatively low transmit power to centrally-located UEs and cancel inter-cell interference at cell-edge UEs by a coordinated symbol repetition. We show that UCA algorithm 2 applied in frequency planning 1 is promising among other combinations of UCA algorithms and frequency palnnings in terms of the low 5th percentile of SINR at UEs.

The Effect of Word Frequency on Resident Education Effectiveness in Rural Field Forums (농촌현장포럼에서 단어의 빈도가 주민교육 효과성에 미치는 영향)

  • Lee, Byungjoon;Yoon, Seongsoo
    • Journal of Korean Society of Rural Planning
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    • v.28 no.3
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    • pp.1-11
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    • 2022
  • In this study, the magnitude of the influence of word frequency on the change of perception of residents before and after resident competency strengthening education in villages where the rural field forum was conducted was analyzed. The results of analyzing the changes in residents' perceptions of the village development project according to the frequency of words are as follows. It was found that talking about surrounding factors had a greater influence than individual factors of keywords. In addition, the frequency of word use had a positive effect on the resident's perception. It was analyzed that items with high awareness of resident prior to resident competency-enhancing education had a low impact.

Analysis of effects on cell planning of IS-95A CDMA network by soft/softer handoff (Upbanded IS-95A CDMA 망에서 Soft/Softer handoff가 망설게에 미치는 영향분석)

  • 최홍석;노종선;박판종
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.9A
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    • pp.2221-2229
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    • 1998
  • Handoff is an important parameter for system performance and capacity analysis in CDMA cell planning. In this paper, simulation tool for analyzing the effects of soft handoff on cell planning of CDMA network is developed by studying propagation model in 1.9GHz frequency specrum, soft hadnoff algorithm given by IS-95, and several parameters for CDMA cell planning. By using the tool, soft handoff gain and effects of soft handoff on cDMA system performance and capacity are analyzed. Research results and simulation tool developed in this paper can be used for optimal CDMA cell planning for PCS and IMT-2000 in 1.9GHz frequency spectrum such as locating base station and parameter optimization.

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Radiotherapy Treatment Planning using Computed Tomography in Breast Cancer (유방암에서 CT planning를 이용한 치료계획)

  • 김성규;신세원;김명세
    • Progress in Medical Physics
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    • v.3 no.2
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    • pp.59-65
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    • 1992
  • Carcimoma of the breast are first frequency malignancy in women in the world. third frequency in Korea. Radiation therapy in breast cancer were treated through opposed tangential fields with photon beam or electron beam. Density within the field and thickness to tumor are very importent factors determining dose distribution in radiation therapy of electron beam. Radiotherapy traetment planning using computed tomography in Breast cancer are able to ideal dose distribution. Authors concluded as following. 6MeV energy of electron beam propered below 1.5cm in chest wall's thickness or internal mammary lymphnode's depth. 9MeV energy of electron beam from 1.5cm to 2.0cm. 12 MeV energy of electron beam from 2.0cm to 2.5cm.

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Uncertainty Analysis for Parameter Estimation of Probability Distribution in Rainfall Frequency Analysis Using Bootstrap (강우빈도해석에서 Bootstrap을 이용한 확률분포의 매개변수 추정에 대한 불확실성 해석)

  • Seo, Young-Min;Park, Ki-Bum
    • Journal of Environmental Science International
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    • v.20 no.3
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    • pp.321-327
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    • 2011
  • Bootstrap methods is the computer-based resampling method that estimates the standard errors and confidence intervals of summary statistics using the plug-in principle for assessing the accuracy or uncertainty of statistical estimates, and the BCa method among the Bootstrap methods is known much superior to other Bootstrap methods in respect of the standards of statistical validation. Therefore this study suggests the method of the representation and treatment of uncertainty in flood risk assessment and water resources planning from the construction and application of rainfall frequency analysis model considersing the uncertainty based on the nonparametric BCa method among the Bootstrap methods for the assessement of the estimation of probability rainfall and the effect of uncertainty considering the uncertainty of the parameter estimation of probability in the rainfall frequency analysis that is the most fundamental in flood risk assessement and water resources planning.

Menu Analysis of the National School Lunch Program : The Comparisons of the Frequency of Menu with the Students' Food Preferences (학교급식 식단 분석 : 초등학교 급식식단의 음식제공빈도와 학생의 음식기호도 비교 연구)

  • Im, Gyeong-Suk;Lee, Tae-Yeong
    • Journal of the Korean Dietetic Association
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    • v.4 no.2
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    • pp.188-199
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    • 1998
  • The menu planning is closely tied to the acceptability of the food and the satisfaction of the food service system to its client, therefore national school lunch program(NSLP) menu should consider the food preferences of the students. To provide appropriate information and guidelines about desirable NSLP menu planning, the comparison between the frequency of NSLP menus and food preferences of the students was performed, NSLP menus with cooking method of 776 meals were collected from 10 elementary NSLP schools in Seoul and Kyunggi province, and food preference data was surveyed with 1618 elementary school students from 4 NSLP schools in Korea in 1995. According to the cooking methods, NSLP menus served Kimchi(98.3%), rice(71.4%) and soup(71.1%) frequently. Based on the food groups, NSLP menus served vegetables most frequently(188%), followed by grains(101.4%), milk(100%), meat(57.3%), fruits(50.3%), and so on. By Spearman Rank Correlations analysis, the serving frequencies of vegetable side dishes(r=.33, p=.05) were positively correlated with the students' preference score. According to the cooking method, the serving frequencies of steamed dishes(r=1.0, p=.00), salads(r=1.0, p=.00), Kimchi(r=.85, p=.01) and rice one-dish meal(r=.80, p=.10) were positively correlated with the students' preference score. However, the serving frequencies of the main dishes(r=.13, p=.57) and soup group(r=.15, p=.57) were not significantly correlated with the students' preference score. Even though the serving frequency of fruit were negatively correlated with the students' preference score(r= -.80, p=.10). These results indicated that the NSLP menu planned the vegetable side dishes in accordance with the students' food preferences, but it planned the main dish, soup group, and meat side dish group discordantly. Therefore further efforts are needed to involve the preferred cooking methods for increasing the food acceptability. It could be used for the basic guidelines for menu planning of NSLP, and for the future improvement of NSLP in Korea.

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Derivation of Green Infrastructure Planning Factors for Reducing Particulate Matter - Using Text Mining - (미세먼지 저감을 위한 그린인프라 계획요소 도출 - 텍스트 마이닝을 활용하여 -)

  • Seok, Youngsun;Song, Kihwan;Han, Hyojoo;Lee, Junga
    • Journal of the Korean Institute of Landscape Architecture
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    • v.49 no.5
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    • pp.79-96
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    • 2021
  • Green infrastructure planning represents landscape planning measures to reduce particulate matter. This study aimed to derive factors that may be used in planning green infrastructure for particulate matter reduction using text mining techniques. A range of analyses were carried out by focusing on keywords such as 'particulate matter reduction plan' and 'green infrastructure planning elements'. The analyses included Term Frequency-Inverse Document Frequency (TF-IDF) analysis, centrality analysis, related word analysis, and topic modeling analysis. These analyses were carried out via text mining by collecting information on previous related research, policy reports, and laws. Initially, TF-IDF analysis results were used to classify major keywords relating to particulate matter and green infrastructure into three groups: (1) environmental issues (e.g., particulate matter, environment, carbon, and atmosphere), target spaces (e.g., urban, park, and local green space), and application methods (e.g., analysis, planning, evaluation, development, ecological aspect, policy management, technology, and resilience). Second, the centrality analysis results were found to be similar to those of TF-IDF; it was confirmed that the central connectors to the major keywords were 'Green New Deal' and 'Vacant land'. The results from the analysis of related words verified that planning green infrastructure for particulate matter reduction required planning forests and ventilation corridors. Additionally, moisture must be considered for microclimate control. It was also confirmed that utilizing vacant space, establishing mixed forests, introducing particulate matter reduction technology, and understanding the system may be important for the effective planning of green infrastructure. Topic analysis was used to classify the planning elements of green infrastructure based on ecological, technological, and social functions. The planning elements of ecological function were classified into morphological (e.g., urban forest, green space, wall greening) and functional aspects (e.g., climate control, carbon storage and absorption, provision of habitats, and biodiversity for wildlife). The planning elements of technical function were classified into various themes, including the disaster prevention functions of green infrastructure, buffer effects, stormwater management, water purification, and energy reduction. The planning elements of the social function were classified into themes such as community function, improving the health of users, and scenery improvement. These results suggest that green infrastructure planning for particulate matter reduction requires approaches related to key concepts, such as resilience and sustainability. In particular, there is a need to apply green infrastructure planning elements in order to reduce exposure to particulate matter.

Performance of Multiple Coordinators-based RFID Reader Protocol (다중 코디네이터를 이용한 RFID 리더 프로토콜 성능 분석)

  • Lee, Se-Hee;Yang, Hoon-Gee;Yang, Sung-Hyun;Kang, Bong-Soon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.10
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    • pp.2247-2256
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    • 2011
  • In this paper, we propose a coordinator-based reader protocol that can avoid reader collisions in a passive RFID system. In a proposed protocol, unlike conventional protocols that a reader itself selects its own slot randomly to communicate with tags such as DCS, Colorwave, a coordinator reader allocates an unused slot to a reader to participate in the network and sends a current slot number. A reader allocated a slot can communicate with tags. The proposed protocol can adaptively modified to apply for multiple coordinator readers environment in a wide area. This causes reader collision problem, but can be alleviated partly by applying the frequency planning. In this way, we verifies that a RFID system using the proposed protocol is three to five times better than existing systems through the simulation.