• 제목/요약/키워드: Large Power System

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A Study on the SCM Integration & Green Growth Strategy of Logistic Company in Korea (물류기업의 SCM통합과 녹색성장을 위한 대응방안에 대한 연구)

  • Jin, Yun-Jun;Lee, Yu-Bin;Bae, Ki-Hyung
    • International Commerce and Information Review
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    • v.15 no.2
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    • pp.3-23
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    • 2013
  • In 1997, 180 countries signed the Kyoto Protocol in Kyoto, Japan. The Kyoto Protocol came into force in February 2005. The agreement calls for industrialized nations to cut greenhouse gas emissions by 5 percent from 1990 levels by 2008 to 2012. One of those polices is a modal shift that change from road freight to sea, inland waterway and railroad transportation that is eco-friendly. The increase of road freight brings road congestion, accidents, logistic costs, air pollution and greenhouse gases. Railroads are superior than the other modes of transportation in mass transportability, high speed, timeliness, safety and environmental-friendliness, but the railway industry has been pushed behind in competition. Korean railroads were used by passengers and freight transport popularly until the middle of 20th century, however, by the sudden change of logistics environments, a shaving time efficiency being most important, railroad logistic lost its competitive power against the transportation by truck. From the research which sees consequently investigated a various policy, a system and a law about Chinese logistics industry and present condition of the Chinese goods enterprise and instance analysis of the large Chinese corporation that branch out to undeveloped markets led and a Chinese logistics industry and problem point escape hereafter the heightening of competitiveness plan which is rational under prsenting boil.

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Hybrid (refrctive/diffractive) lens design for the ultra-compact camera module (초소형 영상 전송 모듈용 DOE(Diffractive optical element)렌즈의 설계 및 평가)

  • Lee, Hwan-Seon;Rim, Cheon-Seog;Jo, jae-Heung;Chang, Soo;Lim, Hyun-Kyu
    • Korean Journal of Optics and Photonics
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    • v.12 no.3
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    • pp.240-249
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    • 2001
  • A high speed ultra-compact lens with a diffractive optical element (DOE) is designed, which can be applied to mobile communication devices such as IMT2000, PDA, notebook computer, etc. The designed hybrid lens has sufficiently high performance of less than f/2.2, compact size of 3.3 mm (1st surf. to image), and wide field angle of more than 30 deg. compared with the specifications of a single lens. By proper choice of the aspheric and DOE surface which has very large negative dispersion, we can correct chromatic and high order aberrations through the optimization technique. From Seidel third order aberration theory and Sweatt modeling, the initial data and surface configurations, that is, the combination condition of the DOE and the aspherical surface are obtained. However, due to the consideration of diffraction efficiency of a DOE, we can choose only four cases as the optimization input, and present the best solution after evaluating and comparing those four cases. On the other hand, we also report dramatic improvement in optical performance by inserting another refractive lens (so-called, field flattener), that keeps the refractive power of an original DOE lens and makes the petzval sum zero in the original DOE lens system. ystem.

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The Study on the Countermeasure Plans about Leakage, Explosion and Fire Accidents of Atmospheric Storage Tank (옥외저장탱크 누출, 폭발 및 화재사고 대응방안에 관한 고찰)

  • Lee, Gab-Kyoo
    • Fire Science and Engineering
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    • v.30 no.6
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    • pp.48-56
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    • 2016
  • A crude oil leakage from a large atmospheric storage tank occurred on 4 April 2014 at 14:50 in Ulsan City, while storing the crude oil in the tank. Emergency Rescue Control Group was deployed in the scene. The company, Fire Service Headquarters and associated agencies got together in Command Post (CP) for discussing an effective corresponding strategy. Many solution plans were drafted in the debate such as power down, stopping the facilities, checking the density of inflammable gas, suppressing oil evaporation, moving the leaked crude oil to a nearby tank and a processing plant and avoiding marine pollution. All the solutions were carried out in cooperation with several agencies and partners. The oil leakage accident was successfully settled up within the process of responding, The Fire Service Headquarters and the company thought that the most important thing was the suppression of oil evaporation and the elimination of ignition source. With Fire Service Headquarters and several agencies' every effort, an explosion and a fire didn't occurred in the scene. This study suggest the improvement of the operating system in Emergency Rescue Control Group in case of petroleum leakage, explosion and fire accidents of atmospheric storage tank, different from a ordinary disaster. Assuming that petroleum leakage in atmospheric storage tank develop the explosion and fire accidents, the spreading speed of the flame and the burning time was experimented and compared with each other. Furthermore, this study concentrates on the effective field response plan prepared for the afterward explosion and fire accidents from petroleum leak in a storage tank, with the database experimented and analyzed in accordance with the angle of radiation in the foam nozzle and the pressure of pumping in a fire engine.

Various Technologies for Simultaneous Removal of NOx and SO2 from Flue Gas (배출가스의 질소산화물과 이산화황 동시 저감 기술)

  • Park, Hyun-Woo;Uhm, Sunghyun
    • Applied Chemistry for Engineering
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    • v.28 no.6
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    • pp.607-618
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    • 2017
  • Harmful air pollutants are exhausted from the various industrial facilities including the coal-fired thermal power plants and these substances affects on the human health as well as the nature environment. In particular, nitrogen oxides ($NO_x$) and sulfur dioxide ($SO_2$) are known to be causative substances to form fine particles ($PM_{2.5}$), which are also deleterious to human health. The integrated system composed of selective catalytic reduction (SCR) and wet flue gas desulfurization (WFGD) have been widely applied in order to control $NO_x$ and $SO_2$ emissions, resulting in high investment and operational costs, maintenance problems, and technical limitations. Recently, new technologies for the simultaneous removal of $NO_x$ and $SO_2$ from the flue gas, such as absorption, advanced oxidation processes (AOPs), non-thermal plasma (NTP), and electron beam (EB), are investigated in order to replace current integrated systems. The proposed technologies are based on the oxidation of $NO_x$ and $SO_2$ to $HNO_3$ and $H_2SO_4$ by using strong aqueous oxidants or oxidative radicals, the absorption of $HNO_3$ and $H_2SO_4$ into water at the gas-liquid interface, and the neutralization with additive reagents. In this paper, we summarize the technical improvements of each simultaneous abatement processes and the future prospect of technologies for demonstrating large-scaled applications.

A Comparative study of Korea and US Intelligence Systems: Focusing on Environment, Intelligence Organizations and Activities (한국과 미국의 정보체계 비교연구 - 환경, 정보조직 및 활동을 중심으로 -)

  • Seok, Jaewang
    • Korean Security Journal
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    • no.58
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    • pp.107-135
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    • 2019
  • The purpose of this paper is to compare and analyze the similarities and differences between the security environment, information organization and information activities of Korea and the United States. The comparison will provide insight into Korea and other national intelligence agencies, as well as methodological advances in information research, by providing insight into the overall information and a broad understanding As the history, culture and national power of Korea and the U.S. are different, the organization and activities of intelligence agencies are also different. First of all, in terms of environment, the U.S. carries out intelligence activities for national interest and security in a wide range of areas ranging from North American continental countries to South America, the Middle East, Asia and Asia, while South Korea's intelligence activities are mainly aimed at North Korea and neighboring countries around the Korean Peninsula. In terms of information organization, U.S. intelligence agencies are separate, whereas domestic and foreign intelligence agencies are separate, whereas Korean intelligence agencies are a type of integrated intelligence agency that combines information and investigation, unlike the U.S. In the U.S., the U.S. also operates as an intelligence community, and there are many flexible organizations such as non-tier organizations and centers. Intelligence activities by U.S. intelligence agencies are mainly focused on analysis and overseas processing activities, while Korean intelligence agencies still account for a large portion of domestic information activities. Despite these differences, Korea's intelligence agency was created by imitating U.S. intelligence agencies, and thus has similar aspects in terms of evaluation of security, organization and activities. However, this similarity is shared by all intelligence agencies, so the article will focus on analyzing differences. Finally, for the development of Korean intelligence agencies, the establishment of an intelligence community and efficient control of the National Assembly will be proposed.

A Fast Inversion for Low-Complexity System over GF(2 $^{m}$) (경량화 시스템에 적합한 유한체 $GF(2^m)$에서의 고속 역원기)

  • Kim, So-Sun;Chang, Nam-Su;Kim, Chang-Han
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.9 s.339
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    • pp.51-60
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    • 2005
  • The design of efficient cryptosystems is mainly appointed by the efficiency of the underlying finite field arithmetic. Especially, among the basic arithmetic over finite field, the rnultiplicative inversion is the most time consuming operation. In this paper, a fast inversion algerian in finite field $GF(2^m)$ with the standard basis representation is proposed. It is based on the Extended binary gcd algorithm (EBGA). The proposed algorithm executes about $18.8\%\;or\;45.9\%$ less iterations than EBGA or Montgomery inverse algorithm (MIA), respectively. In practical applications where the dimension of the field is large or may vary, systolic array sDucture becomes area-complexity and time-complexity costly or even impractical in previous algorithms. It is not suitable for low-weight and low-power systems, i.e., smartcard, the mobile phone. In this paper, we propose a new hardware architecture to apply an area-efficient and a synchronized inverter on low-complexity systems. It requires the number of addition and reduction operation less than previous architectures for computing the inverses in $GF(2^m)$ furthermore, the proposed inversion is applied over either prime or binary extension fields, more specially $GF(2^m)$ and GF(P) .

Microstructural Characteristics of III-Nitride Layers Grown on Si(110) Substrate by Molecular Beam Epitaxy

  • Kim, Young Heon;Ahn, Sang Jung;Noh, Young-Kyun;Oh, Jae-Eung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.327.1-327.1
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    • 2014
  • Nitrides-on-silicon structures are considered to be an excellent candidate for unique design architectures and creating devices for high-power applications. Therefore, a lot of effort has been concentrating on growing high-quality III-nitrides on Si substrates, mostly Si(111) and Si(001) substrates. However, there are several fundamental problems in the growth of nitride compound semiconductors on silicon. First, the large difference in lattice constants and thermal expansion coefficients will lead to misfit dislocation and stress in the epitaxial films. Second, the growth of polar compounds on a non-polar substrate can lead to antiphase domains or other defective structures. Even though the lattice mismatches are reached to 16.9 % to GaN and 19 % to AlN and a number of dislocations are originated, Si(111) has been selected as the substrate for the epitaxial growth of nitrides because it is always favored due to its three-fold symmetry at the surface, which gives a good rotational matching for the six-fold symmetry of the wurtzite structure of nitrides. Also, Si(001) has been used for the growth of nitrides due to a possible integration of nitride devices with silicon technology despite a four-fold symmetry and a surface reconstruction. Moreover, Si(110), one of surface orientations used in the silicon technology, begins to attract attention as a substrate for the epitaxial growth of nitrides due to an interesting interface structure. In this system, the close lattice match along the [-1100]AlN/[001]Si direction promotes the faster growth along a particular crystal orientation. However, there are insufficient until now on the studies for the growth of nitride compound semiconductors on Si(110) substrate from a microstructural point of view. In this work, the microstructural properties of nitride thin layers grown on Si(110) have been characterized using various TEM techniques. The main purpose of this study was to understand the atomic structure and the strain behavior of III-nitrides grown on Si(110) substrate by molecular beam epitaxy (MBE). Insight gained at the microscopic level regarding how thin layer grows at the interface is essential for the growth of high quality thin films for various applications.

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A High Performance Flash Memory Solid State Disk (고성능 플래시 메모리 솔리드 스테이트 디스크)

  • Yoon, Jin-Hyuk;Nam, Eyee-Hyun;Seong, Yoon-Jae;Kim, Hong-Seok;Min, Sang-Lyul;Cho, Yoo-Kun
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.4
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    • pp.378-388
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    • 2008
  • Flash memory has been attracting attention as the next mass storage media for mobile computing systems such as notebook computers and UMPC(Ultra Mobile PC)s due to its low power consumption, high shock and vibration resistance, and small size. A storage system with flash memory excels in random read, sequential read, and sequential write. However, it comes short in random write because of flash memory's physical inability to overwrite data, unless first erased. To overcome this shortcoming, we propose an SSD(Solid State Disk) architecture with two novel features. First, we utilize non-volatile FRAM(Ferroelectric RAM) in conjunction with NAND flash memory, and produce a synergy of FRAM's fast access speed and ability to overwrite, and NAND flash memory's low and affordable price. Second, the architecture categorizes host write requests into small random writes and large sequential writes, and processes them with two different buffer management, optimized for each type of write request. This scheme has been implemented into an SSD prototype and evaluated with a standard PC environment benchmark. The result reveals that our architecture outperforms conventional HDD and other commercial SSDs by more than three times in the throughput for random access workloads.

Development on Glass Formulation for Aluminum Metal and Glass Fiber (유리섬유 및 알루미늄 금속 혼합물 유리조성 개발)

  • Cho, Hyun-Je;Kim, Cheon-Woo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.10 no.4
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    • pp.247-254
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    • 2012
  • Vitrification technology has been widely applied as one of effective processing methods for wastes generated in nuclear power plants. The advantage of vitrifying for low- and intermediate-level radioactive wastes has a large volume reduction and good durability for the final products. Recently, a filter using on HVAC(Heating Ventilating & Air Conditioning System) is composed with media (glass fiber) and separator (aluminum film) has been studied the proper treatment technology for meeting the waste disposal requirement. Present paper is a feasibility study for the filter vitrification that developing of the glass compositions for filter melting and melting test for physicochemical characteristic evaluation. The aluminum metal of film type is preparing with 0.5 cm size for proper mixing with glass frit, glass fiber is also preparing with 1 cm size within crucible. The glass compositions should be developed considering molten glass are related with wastes reduction. Glass compositions obtained from developing on glass formulation are mainly composed of $SiO_2$ and $B_2O_3$ for aluminum metal. A variety of factors obtained from the glass formulation and melting test are reviewed, which is feeding rate and glass characteristics of final products such as durability for implementing the wastes disposal requirement.

The Evaluation of Minimum Cooling Period for Loading of PWR Spent Nuclear Fuel of a Dual Purpose Metal Cask (국내 경수로 사용후핵연료의 금속 겸용용기 장전을 위한 최소 냉각기간 평가)

  • Dho, Ho-Seog;Kim, Tae-Man;Cho, Chun-Hyung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.14 no.4
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    • pp.411-422
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    • 2016
  • Recently, because the wet pool storage facilities of NPPs in Korea has become saturated, there has been much active R&D on an interim dry storage system using a transportation and storage cask. Generally, the shielding evaluation for the design of a spent fuel transportation and storage cask is performed by the design basis fuel, which selects the most conservative fuel among the fuels to be loaded into the cask. However, the loading of actual spent fuel into the transportation metal cask is not limited to the design basis fuel used in the shielding evaluation; the loading feasibility of actual spent fuel is determined by the shielding evaluation that considers the characteristics of the initial enrichment, the maximum burnup and the minimum cooling period. This study describes a shielding analysis method for determining the minimum cooling period of spent fuel that meets the domestic transportation standard of the dual purpose metal cask. In particular, the spent fuel of 3.0~4.5wt% initial enrichment, which has a large amount of release, was evaluated by segmented shielding calculations for efficient improvement of the results. The shielding evaluation revealed that about 81% of generated spent fuel from the domestic nuclear power plants until 2008 could be transported by the dual purpose metal cask. The results of this study will be helpful in establishing a technical basis for developing operating procedures for transportation of the dual purpose metal cask.