• Title/Summary/Keyword: 2 order system

Search Result 14,811, Processing Time 0.052 seconds

A Digital Up-Down Conversion for Wibro Repeater using IIR Filters having Almost Linear Phase Response (유사 선형 위상 특성을 갖는 IIR 필터군을 이용한 Wibro용 디지털 상하향 변환 연구)

  • Chang, Hyung-Min;Lee, Won-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.34 no.2C
    • /
    • pp.209-216
    • /
    • 2009
  • The repeater for wireless broadband internet (Wibro) system using OFDM demands the short processing delay to eliminate inter-symbol interference resulted from the time delay greater than the guard time. Towards this, the total system delay of repeater is expected to be minimized as possible as it can without distorting signal quality. In general, the FIR-type of filter is commonly deployed as a channelization filter, but due to its large amount of coefficients for producing prerequisite filter response the excessive large time delay occurs. To withstand this problem, the paper proposes the method for designing IIR filter whose response almost identical to that of the original filter. Moreover, in order to linearize the phase response of the designed IIR filter, this paper also introduce the way of designing the all-pass filter to be cascaded works for linearizing phase response of the channelization as well as the de-channelization filter. To achieve the further improvement in linearization of the phase response and reduction of the overall complexity, this paper tries to transform the integrated IIR filter group into the structure in polyphase style. The computer simulation verifies that the integrated IIR filter group designed in this paper reveals the relatively short processing delay without harming the acceptible signal quality.

A Practical Research for Mode Efficient Utilization of Estuary Reserviors in the South-Western Part of Korea (우리나라 서남부지역 담수호의 효율적 이용방안)

  • Kim, Hyeon-Yeong;Seo, Yeong-Je
    • Journal of Korea Water Resources Association
    • /
    • v.31 no.4
    • /
    • pp.385-396
    • /
    • 1998
  • The south-western part of Korea is situated in an unbalance of water supply and demand relating to the Keum, Mankyung, Dongjin and Youngsan River and their estuary reservoirs. For example, the Keum River estuary reservoir is discharging the larger amount of yearly runoff into the sea due to the small storage capacity, while Saemankeum estuary reservoir which is under construction, has the smaller runoff comparing with its strorage capacity. And the downstream area of the Youngsan River, such as Youngkwang, Youngam are deficient in water due to larger demand and smaller supply. In order to solve the above unbalanced water supply and demand and also to improve the water use effciency, the Hierarchical Operation Model for Multi-reservoir System(HOMMS) has been developed and applied to analyze the multi-reservoir operation assuming that the above reservoirs were linked each other. The result of this study shows that $2,148{\times}106\;\textrm{m}^3$ of annual additional water requirement for agricultural and rural water demands are required in this region at 2011 of target year, and these demands can be resolved by diverting and reusing $1,913{\times}106\;\textrm{m}^3$ of the released water from the estuary reservoirs into the sea.

  • PDF

Old Age Workers' Labor Market: A Model for Understanding Its Structure and Policy Implication (고령자 임금노동시장의 구조와 정책적 시사)

  • Hur, Jai-Joon
    • Korea journal of population studies
    • /
    • v.21 no.2
    • /
    • pp.58-82
    • /
    • 1998
  • It is usually proposed that job security of old age workers is hampered by the structure of wage increasing with age. This paper sets forth a model to comprehend the characteristic of the old age workers' labor market and policy implications derived from it. In order to stimulate demand for old age workers, policy initiatives should be taken as follows : the wage criteria should be simplified which apply differently from one institution to other; incentives relatively favorable for employing old age workers' in manufacturing sector should be also given to service sectors; employment subsidy or other tax incentives should be given for labor contract after the retirement age; licensing and evaluation system for job ability should be introduced based on occupation & job analysis. To lower the reservation wage of workers, mortgage loan for house and long-term low interest loan for tuition fees should be developed together with stabilization of housing cost. Wedding culture which requires high expense should be amended. Above all, it is necessary to install reasonable social security system. Policy orientation should also pay attention to reduce labor supply of the old aged via aiding old age workers' firm opening and voluntary civil service together with developing various honor programs for members of civil corps.

  • PDF

The New X-ray Induced Electron Emission Spectrometer

  • Yu.N.Yuryev;Park, Hyun-Min;Lee, Hwack-Ju;Kim, Ju-Hwnag;Cho, Yang-Ku;K.Yu.Pogrebitsky
    • Proceedings of the Korea Crystallographic Association Conference
    • /
    • 2002.11a
    • /
    • pp.5-6
    • /
    • 2002
  • The new spectrometer for X-ray Induced Electron Emission Spectroscopy (XIEES) .has been recently developed in KRISS in collaboration with PTI (Russia). The spectrometer allows to perform research using the XAFS, SXAFS, XANES techniques (D.C.Koningsberger and R.Prins, 1988) as well as the number of techniques from XIEES field(L.A.Bakaleinikov et all, 1992). The experiments may be carried out with registration of transmitted through the sample x-rays (to investigate bulk samples) or/and total electron yield (TEY) from the sample surface that gives the high (down to several atomic mono-layers in soft x-ray region) near surface sensitivity. The combination of these methods together give the possibility to obtain a quantitative information on elemental composition, chemical state, atomic structure for powder samples and solids, including non-crystalline materials (the long range order is not required). The optical design of spectrometer is made according to Johannesson true focusing schematics and presented on the Fig.1. Five stepping motors are used to maintain the focusing condition during the photon energy scan (crystal angle, crystal position along rail, sample goniometer rail angle, sample goniometer position along rail and sample goniometer angle relatively of rail). All movements can be done independently and simultaneously that speeds up the setting of photon energy and allows the using of crystals with different Rowland radil. At present six curved crystals with different d-values and one flat synthetic multilayer are installed on revolver-type monochromator. This arrangement allows the wide range of x-rays from 100 eV up to 25 keV to be obtained. Another 4 stepping motors set exit slit width, sample angle, channeltron position and x-ray detector position. The differential pumping allows to unite vacuum chambers of spectrometer and x-ray generator avoiding the absorption of soft x-rays on Be foil of a window and in atmosphere. Another feature of vacuum system is separation of walls of vacuum chamber (which are deformed by the atmospheric pressure) from optical elements of spectrometer. This warrantees that the optical elements are precisely positioned. The detecting system of the spectrometer consists of two proportional counters, one scintillating detector and one channeltron detector. First proportional counter can be used as I/sub 0/-detector in transmission mode or by measuring the fluorescence from exit slit edge. The last installation can be used to measure the reference data (that is necessary in XANES measurements), in this case the reference sample is installed on slit knife edge. The second proportional counter measures the intensity of x-rays transmitted through the sample. The scintillating detector is used in the same way but on the air for the hard x-rays and for alignment purposes. Total electron yield from the sample is measured by channeltron. The spectrometer is fully controlled by special software that gives the high flexibility and reliability in carrying out of the experiments. Fig.2 and fig.3 present the typical XAFS spectra measured with spectrometer.

  • PDF

Changes in Physicochemical Properties of Rice Starch from Rice Stored at Different Conditions (저장조건에 따른 쌀전분의 이화학적 성질 변화)

  • Ko, Yong-Duck;Choi, Ok-Ja;Park, Seok-Kyu;Ha, Hee-Suk;Sung, Nack-Kie
    • Korean Journal of Food Science and Technology
    • /
    • v.27 no.3
    • /
    • pp.306-312
    • /
    • 1995
  • In order to know properties in rice starch during storage of rice, rice starch from stored rice(stored at $5^{\circ}C$, R.H. 65% and $30^{\circ}C$, R.H. 85%, for 16 weeks) used in this experiment. Water binding capacity of rice starch increased for 8 weeks, and then it decreased. As the storage period took longer, swelling power and solubility, optical transmittance, blue value, total amylose content and soluble amylose content decreased. For the same periods, changes in rice starch from stored rice$(30^{\circ}C$, R.H. 85%) were made more than those in rice starch at $5^{\circ}C$, R.H. 65%. The granule shape of rice starch, irrespective of storage periods and conditions, didn't make a significant difference. The relative crystallinity of the rice starch by X-ray diffraction didn't distinctly changed till the second week. But, at the fourth week, that by X-ray diffraction significantly decreased, and then slightly decreased. As the storage period took longer, gelatinization temperature, melting temperature and melting enthalpy measured by DSC got higher, but gelatinization enthalpy got lower. For the same storage period, gelatinization temperature, melting temperature, gelatinization enthalpy and melting enthalpy of rice starch stored at $30^{\circ}C$, R.H. 85% made changes more than those of rice starch stored at $5^{\circ}C$, R.H. 65% did.

  • PDF

A Study on Renewable Energy Policy and Sustainable Development Strategy: German Model and Implication (재생에너지정책과 지속가능발전전략에 관한 연구: 독일모델과 시사점)

  • Park, Sang-Chul
    • Environmental and Resource Economics Review
    • /
    • v.25 no.1
    • /
    • pp.61-87
    • /
    • 2016
  • Germany has carried out its environment friendly energy policy to prevent $CO_2$ emission that affects directly to the global warming phenomenon. Based on this direction, it has performed a sustainable development strategy through the R & D activities in environment and energy technologies. Accordingly, the core elements of German energy and sustainable development policies are renewable energy, ecological energy tax, and emission trading system. In particular, Germany has supported to develop renewable energy resources that prevents from consuming fossil energy resources. At the same time, it has set the ecological energy tax and initiated the emission trading system in order to support the renewable energy policy continuously. This paper analyze whether or not it is possible to generate an economic growth and a sustainable development while using renewable energy resources based on the renewable energy policy that minimize the negative effects on the environment. For that, the paper adopts Germany as a model country. In fact, it is possible to achieve the economic growth and the sustainable development if a nation can substitute increasing energy consumption for the economic growth to renewable energy resources that does not affect to the environment negatively. This model is the German energy policy and sustainable development strategy, and it is the purpose of the paper to prove it logically.

A Study on the Web-based Map Algebraic Processor (웹 기반 지도대수 처리기에 관한 연구)

  • 박기호
    • Spatial Information Research
    • /
    • v.5 no.2
    • /
    • pp.147-160
    • /
    • 1997
  • "The "Map Algebra", beeing recognized as a viable theoretical framework for GIS (Geographica Infonnation System), models map layers as "operands" which are the basic unit of geo-processing, and a variety of GIS commands as "operators." In this paper, we attempt at lifting some limitations of map algebras proposed in GIS literature. First, we model map layer as "function" such that we may employ the notion of meta operator (or, higher-order funtion) available in the functional programming paradigm. This approach provides map algebraic language with "programmability" needed in GIS user language. Second, we extend the semantics of, and improve on the sytactic structure of map algebraic language. Mer the data model and language associated with map algebra are formalized, we proceed to design and implement a prototype of map algebraic processor. The parser of the language in our prototype plays the role of transforming the native and heterogeneous user language of current GISs into a canonical map algebraic language. The prototype, named "MapSee" is a proof-of-concept system for the ideas we propsed in this paper. We believe that the uniform interface based on the map algebraic language will make promising infrastructure to support "Internet GIS." This is because the uniform but powerful interface through the Web clients allow access to both geo-data and geo-processing resources distributed over the network.to both geo-data and geo-processing resources distributed over the network.

  • PDF

A Study on the Improvement of Efficient Execution System for Cadastral Resurvey Project (지적재조사사업의 효율적인 추진체계 개선에 관한 연구)

  • Kim, Jae Myeong;Choi, Yun Soo;Yoon, Ha Su;Kim, Young Dan
    • Spatial Information Research
    • /
    • v.21 no.4
    • /
    • pp.47-62
    • /
    • 2013
  • Recently there are growing arguments about the needs to improve Cadastral Resurvey Projects more efficiently and rationally since the projects have realistically started. This study aims to analysis some problems of the projects and finds out the solutions. With this purpose, we have surveyed some literatures related to the demonstration projects, and then have examined some similar domestic urban development projects and international Cadastral Resurvey Projects in order to apply their appropriate tools to the present or future projects. Generally the execution process of Cadastral Resurvey Projects has four steps and this study arranges the main problems in each steps. In the result it suggests that some improvements should change as the followings. (1) It is more effective to take planning-based approach than project-based one. (2) The project boundary needs to be decided with the rectangular patterns not the irregular ones for the efficient project. (3) The adjusting the current baseline of agreement should be reconsidered because too high baseline may make the project difficult to progress. (4) Not only systematical public relations to promote the projects but also a variety of incentives to induce the public participations is very important to solve the problems of involvement. (5) Institutional tools for collaborate planning is also desirable to solve the conflicts among stakeholders rationally and effectively.

A Sustainability Study Based on Farm Management Value-Chain Structure (농업경영의 가치사슬 구조에 근거한 지속가능성 연구)

  • Cheong, Hoon-Hui;Kim, Sa-Gyun;Heo, Seoung-Wook
    • Journal of Agricultural Extension & Community Development
    • /
    • v.16 no.2
    • /
    • pp.363-384
    • /
    • 2009
  • This study aimed at finding directions for Korean agriculture to establish a new paradigm of sustainable development. Various problematic issues and concerns in the environment necessitate the transformation of Korea's development paradigm from unconditional growth to "Green Growth" through new policies on green value and review of various advanced researches. In this research, the environment-friendly agriculture's problems, particularly in agribusiness were analyzed. Drawing from Michael Porter's Value Chain Analysis, this research developed a value chain model in agriculture that reflects the environment and the present situations. Future directions in the agriculture sector were also discussed. Korea realized food self-sufficiency through the green revolution in the early 1970s. However, a lot of problems have also occurred, including ground and water pollution and the destruction of ecosystems as a result of the overuse of pesticides and chemical fertilizers. In the late 1970s, the growing interest on environment-friendly agriculture led to the introduction of sustainable methods and techniques. Unfortunately however, these were not innovative enough to foster environment-friendly agriculture. Thereafter, the consumers' distrust on agricultural products has worsened and concerns about health have increased. In view of this, the Ministry of Food, Agriculture, Forestry and Fisheries introduced in December 1993 a system of Quality-Certified Products for organic and pesticide-free agri-foods. Although a fundamental step toward the sustainability of the global environment, this system was not enough to promote environment-friendly agriculture. In 2008, Korea's vision is for "Low Carbon Green Growth" to move forward while also coping with climate change. But primary sectors in a typical value chain do not consider the green value of their operations nor look at production from an environmental perspective. In order to attain sustainable development, there is a need to use less resources and energy than what is presently used in Korean agricultural and value production. The typical value chain should be transformed into a "closed-loop" such that the beginning and the end of the chain are linked together. Such structure allows the flow of materials, products and even wastes among participants in the chain in a sustained cycle. This may result in a zero-waste sustainable production without destroying the ecosystem.

  • PDF

The Spectral Characteristics of Climatological Variables over the Asian Dust Source Regions and its Association with Particle Concentrations in Busan (황사 발원지 기후자료의 시계열 특성과 부산지역 먼지 농도의 연관성 분석)

  • Son, Hye-Young;Kim, Cheol-Hee
    • Journal of the Korean earth science society
    • /
    • v.30 no.6
    • /
    • pp.734-743
    • /
    • 2009
  • In order to examine how climatological condition can influence on urban scale particulate air pollutants, single and cross spectrum analysis have been performed to daily mean concentrations of particulate matters ($PM_{10}$) in Busan together with the climatological variables over the Asian dust source regions. Single power spectrum analysis of $PM_{10}$ concentrations in Busan shows that, aside from the typical and well-known periodicities, 3-4 year of peak periodicity of power spectrum density was identified. In cross spectrum analysis, this 3-4 year periodicity is found to have a strong positive correlation with the wind speed and pressure, and negative with the temperature and relative humidity, which is rather consistent with both characteristics of air mass during the Asian dust event whose periodicities have been recorded inter-annually over the Korean urban cities. Over the Asian dust source regions, $PM_{10}$ vs. precipitation shows no significant periodicity from the time series of precipitation data, but the periodicity of EDI (Effective Drought Index) shows some interannual variabilities ranging from 2 to 4 years over the various source regions, suggesting that, rather than precipitation itself, the EDI could be more closely associated with the occurrence frequency of Asian dust and interannual variability of urban particle concentrations in Korean cities.