• Title/Summary/Keyword: time complexity

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On Designing Domino CMOS Circuits for High Testability (고 Testability를 위한 Domino CMOS회로의 설계)

  • 이재민;강성모
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.3
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    • pp.401-417
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    • 1994
  • In this paper, a new testable design technique for domino CMOS circuits is proposed to detect stuck-at(s-at), stuck-open(s-op) and stuck-on(s-on) faults in the circuits by observing logic test reponses. The proposed technique adds one pMOS transistor per domino CMOS gate for s-op and s-on faults testing of nMOS transistors and one nMOS transistors and one nMOS transistor per domino gate or multilevel circuit to detect s-on faults in pMOS transistors of inverters in the circuit. The extra transistors enable the proposed testable circuit to operate like a pseudo static nMOS circuit while testing nMOS transistors in domino CMOS circuits. Therefore, the two=phase operation of a precharge phase and a evaluation phase is not needed to keep the domino CMOS circuit from malfunctionong due to circuit delays in the test mode, which reduces the testing time and the complexity of test generation. Most faults of th transistors in the proposed testable domino CMOS circuit can be detected by single test patterns. The use of single test patterns makes the testing of the proposed testable domino CMOS circuit free from path delays, timing skews, chage sharing and glitches. In the proposed design, the testing of the faults which, require test sequences also becomes free from test invalidation. The conventional automatic test pattern generators(ATPG) can be used for generating test patterns to detect faults in the circuits.

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A Study on the Relationship between Injury Preventive Behaviors and Accidents for Elementary School Children (초등학교 아동의 사고예방행동과 사고발생의 관련성 연구)

  • 이수정;이명선
    • Korean Journal of Health Education and Promotion
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    • v.14 no.1
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    • pp.147-160
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    • 1997
  • Nowadays according to the complexity of our daily life due to the development of industry and transportation various kinds of injuries happen. Since 1993 the death rate among 5-14 age children by injuries amount to about 57%. Furthermore, the injury of children can give a direct damage to their own family and it can also bring a serious loss to the country as well as the community where they live in accord with degree of an injury. From this reason, the importance of safety education has been increasing. In this study, it is aimed to clarify the effect of injury preventive behaviors on injury incidence of the 6th grade students in the elementary school. This study is accomplished by the survey sampled from 9 elementary schools in seoul, each of which belong to different district. The survey took for 15 days from the date of september 10th 1996 to september 25th 1996 and the results were as follows; 1. For demographic characteristic, sexual distribution was 48.7% of male students and 47.1% of female students. The required time from home to school was 10-19 minutes(51.8%), and the most way of their going to school is to walk(89.7%). Mothers who graduated from high school were 46.6% and 49.4% of fathers were above university graduated level. The most vocation of mothers was housewife as 56.7%. 2. The results of analysis on the injury rates, 75.8% of children experienced more than one injury and the most was play injury. With regards to sites where injuries happened, the room, the kitchen, and the living room in the house ranked first(38.3%) and then injuries at school such as on the playground, in the classroom, and on the stairs was 34.1%. 3. Considering the rate of injury incidence in accordance with demographic characteristics, male students experienced more injuries than female students(p〈0.05). For the way from home to school, children who went to school by bicycle experienced the most injuries and then on foot, by bus in order of which differences were statistically significant(p〈0.05). 4. From the comparison of parents' safety education practice and the injury incidence, the less often parents practice safety education, the more often children experience injuries(p〈0.05). 5. The results of analysis on the effect of injury preventive behaviors on accidents children who didn't act injury preventive behaviors experienced much more injuries than those who did injury preventive behaviors of which differences were statistically significant(p〈0.01). 6. From the results of analysis of factors effecting on the elementary school children's injuries, children without injury preventive behaviors had more effect on accidents than those who had injury preventive behaviors as odds ratio 2.06(p〈0.01), and the odds ratio of male students compared with female students was 1.47(p〈0.05).

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A Design of DLL-based Low-Power CDR for 2nd-Generation AiPi+ Application (2세대 AiPi+ 용 DLL 기반 저전력 클록-데이터 복원 회로의 설계)

  • Park, Joon-Sung;Park, Hyung-Gu;Kim, Seong-Geun;Pu, Young-Gun;Lee, Kang-Yoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.4
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    • pp.39-50
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    • 2011
  • In this paper, we presents a CDR circuit for $2^{nd}$-generation AiPi+, one of the Intra-panel Interface. The speed of the proposed clock and data recovery is increased to 1.25 Gbps compared with that of AiPi+. The DLL-based CDR architecture is used to generate the multi-phase clocks. We propose the simple scheme for frequency detector (FD) to mitigate the harmonic-locking and reduce the complexity. In addition, the duty cycle corrector that limits the maximum pulse width is used to avoid the problem of missing clock edges due to the mismatch between rising and falling time of VCDL's delay cells. The proposed CDR is implemented in 0.18 um technology with the supply voltage of 1.8 V. The active die area is $660\;{\mu}m\;{\times}\;250\;{\mu}m$, and supply voltage is 1.8 V. Peak-to-Peak jitter is less than 15 ps and the power consumption of the CDR except input buffer, equalizer, and de-serializer is 5.94 mW.

Design of a Low-Power CMOS Fractional-N Frequency Synthesizer for 2.4GHz ISM Band Applications (2.4GHz ISM 대역 응용을 위한 저전력 CMOS Fractional-N 주파수합성기 설계)

  • Oh, Kun-Chang;Kim, Kyung-Hwan;Park, Jong-Tae;Yu, Chong-Gun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.6
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    • pp.60-67
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    • 2008
  • A low-power 2.4GHz fractional-N frequency synthesizer has been designed for 2.4GHz ISM band applications such as Bluetooth, Zigbee, and WLAN. To achieve low-power characteristic, the design has been focused on the power optimization of power-hungry blocks such as VCO, prescaler, and ${\Sigma}-{\Delta}$ modulator. An NP-core type VCO is adopted to optimize both phase noise and power consumption. Dynamic D-F/Fs with no static DC current are employed in designing the low-power prescaler circuit. The ${\Sigma}-{\Delta}$ modulator is designed using a modulus mapping circuit for reducing hardware complexity and power consumption. The designed frequency synthesizer which was fabricated using a $0.18{\mu}m$ CMOS process consumes 7.9mA from a single 1.8V supply voltage. The experimental results show that a phase noise of -118dBc/Hz at 1MHz offset, the reference spur of -70dBc at 25MHz offset, and the channel switching time of $15{\mu}s$ over 25MHz transition have been achieved. The designed chip occupies an area of $1.16mm^2$ including pads where the core area is only $0.64mm^2$.

Study on the Local Weather Characteristics using Observation Data at the Boseong Tall Tower (보성 종합기상탑 자료를 활용한 국지기상 특성 연구)

  • Hwang, Sung Eun;Lee, Young Tae;Shin, Seung Sook;Kim, Ki Hoon
    • Journal of the Korean earth science society
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    • v.41 no.5
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    • pp.459-468
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    • 2020
  • In this study, the selection criteria for the occurrence of sea breezes in the Boseong area during the spring season (March-May) of 2016-2017 were prepared for the analysis of vertical weather characteristics. For this purpose, wind speed values were determined using the measured precipitation, cloud volume, wind direction, the difference between the ground and sea temperature, a wind Profiler at an altitude of 1 km, and numerical model data. The dates of the sea breezes in Boseong were classified according to the selection criteria, and the spatial and temporal characteristics of the sea breezes were identified by analyzing the time and altitude of the sea breeze and the size of the wind speed. Sea breezes occurred 23 out of 183 days (12%), and in Boseong, at least 1.2 out of 10 spring days exhibited sea breezes. Sea winds ranged from 1200 to 1800 LST, mainly from ground to 700 m altitude during the day. In addition, the maximum wind speed averaged 4.9 m s-1, at an altitude of 40 m at 1600 LST, showing relatively lower values than those in a preceding study. This seems to be owing to the reduction in wind speed due to the complexity of the coastal terrain.

A Novel Video Copy Detection Method based on Statistical Analysis (통계적 분석 기반 불법 복제 비디오 영상 감식 방법)

  • Cho, Hye-Jeong;Kim, Ji-Eun;Sohn, Chae-Bong;Chung, Kwang-Sue;Oh, Seoung-Jun
    • Journal of Broadcast Engineering
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    • v.14 no.6
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    • pp.661-675
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    • 2009
  • The carelessly and illegally copied contents are raising serious social problem as internet and multimedia technologies are advancing. Therefore, development of video copy detection system must be settled without delay. In this paper, we propose the hierarchical video copy detection method that estimates similarity using statistical characteristics between original video and manipulated(transformed) copy video. We rank according to luminance value of video to be robust to spacial transformation, and choose similar videos categorized as candidate segments in huge amount of database to reduce processing time and complexity. The copy videos generally insert black area in the edge of the image, so we remove rig black area and decide copy or not by using statistical characteristics of original video and copied video with center part of frame that contains important information of video. Experiment results show that the proposed method has similar keyframe accuracy to reference method, but we use less memory to save feature information than reference's, because the number of keyframes is less 61% than that of reference's. Also, the proposed method detects if the video is copied or not efficiently despite expansive spatial transformations such as blurring, contrast change, zoom in, zoom out, aspect ratio change, and caption insertion.

Diagonalized Approximate Factorization Method for 3D Incompressible Viscous Flows (대각행렬화된 근사 인수분해 기법을 이용한 3차원 비압축성 점성 흐름 해석)

  • Paik, Joongcheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.3B
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    • pp.293-303
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    • 2011
  • An efficient diagonalized approximate factorization algorithm (DAF) is developed for the solution of three-dimensional incompressible viscous flows. The pressure-based, artificial compressibility (AC) method is used for calculating steady incompressible Navier-Stokes equations. The AC form of the governing equations is discretized in space using a second-order-accurate finite volume method. The present DAF method is applied to derive a second-order accurate splitting of the discrete system of equations. The primary objective of this study is to investigate the computational efficiency of the present DAF method. The solutions of the DAF method are evaluated relative to those of well-known four-stage Runge-Kutta (RK4) method for fully developed and developing laminar flows in curved square ducts and a laminar flow in a cavity. While converged solutions obtained by DAF and RK4 methods on the same computational meshes are essentially identical because of employing the same discrete schemes in space, both algorithms shows significant discrepancy in the computing efficiency. The results reveal that the DAF method requires substantially at least two times less computational time than RK4 to solve all applied flow fields. The increase in computational efficiency of the DAF methods is achieved with no increase in computational resources and coding complexity.

On-line Handwriting Chinese Character Recognition for PDA Using a Unit Reconstruction Method (유닛 재구성 방법을 이용한 PDA용 온라인 필기체 한자 인식)

  • Chin, Won;Kim, Ki-Doo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.1
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    • pp.97-107
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    • 2002
  • In this paper, we propose the realization of on-line handwritten Chinese character recognition for mobile personal digital assistants (PDA). We focus on the development of an algorithm having a high recognition performance under the restriction that PDA requires small memory storage and less computational complexity in comparison with PC. Therefore, we use index matching method having computational advantage for fast recognition and we suggest a unit reconstruction method to minimize the memory size to store the character models and to accomodate the various changes in stroke order and stroke number of each person in handwriting Chinese characters. We set up standard model consisting of 1800 characters using a set of pre-defined units. Input data are measured by similarity among candidate characters selected on the basis of stroke numbers and region features after preprocessing and feature extracting. We consider 1800 Chinese characters adopted in the middle and high school in Korea. We take character sets of five person, written in printed style, irrespective of stroke ordering and stroke numbers. As experimental results, we obtained an average recognition time of 0.16 second per character and the successful recognition rate of 94.3% with MIPS R4000 CPU in PDA.

A Fast Multipoint-to-Point LSP Traffic Engineering for Differentiated Service in MPLS Networks (MPLS 망에서 차별화 된 서비스를 제공하기 위한 빠른 Multipoint-to-Point LSP 결정 방식)

  • Kim, Seong-Gwan;Jo, Yeong-Jong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.5
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    • pp.232-242
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    • 2002
  • In a MPLS(Multiprotocol Label Switching) network, it is important to reduce the number of labels and LSP(Lable Switched Path)s for network resource management. MTP(Multipoint-to-Point) LSP can be used to solve this problem. In consideration of traffic engineering, MTP LSP must be chosen to enhance the availability of network and link utilization. Also, a fast mechanism to setup MTP LSPs is required for rerouting capability against link failure. In this paper, we propose a fast MTP LSP traffic engineering of multipath MTP LSP by using a mapping of a MTP LSP upon Diffserv PHBs(Per Hop Behavior) in a Diffserv-capable MPLS network. In the proposed traffic engineering, we determine multiple MTP LSPs in a hierarchical manner according to the characteristics of different services. By using Monte-Carlo method for traffic load balancing process, it provides fast rerouting capability in case of frequent link failure across large network. Out method produces to be nearly optimal within reasonable run-times. It's time complexity is in O( Cn$^2$logn) as conventional multipath routing and it is much faster than Linear Programming approach. Simulation results show that the proposed traffic engineering can be controlled effectively in an administrative manner and enhance the availability of network in comparison with conventional multipath routing.

An Empirical Study on the Effect of Information Sharing Level on Supply Chain Integration between Companies and Corporate's Performance (기업 간 정보공유수준이 공급사슬통합과 기업성과에 미치는 영향에 관한 실증연구)

  • Kim, Hyun-Chung;Lee, Choong-Bae
    • Journal of Korea Port Economic Association
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    • v.36 no.1
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    • pp.141-164
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    • 2020
  • With business environments around the world facing uncertainty and complexity, companies have focused on supply chain management as one of the essential elements in securing a competitive advantage. Successful supply chain management requires internal efforts to strengthen the core competencies of the company and the integration of individual functions in the supply chain. This study aims to investigate the effect of information sharing between companies on supply chain integration and corporate performance. The research hypothesis established in previous studies was analyzed using structural equation modeling. A total of 723 questionnaire responses were used to test the hypotheses of this study. We found that the integration and sharing of information between companies have a great influence on supply chain integration, which has positive effects on corporate performance at the operational and strategic levels, including finance, market share, and customer satisfaction. The integration of supply chains via information integration and sharing between companies can promote the flow of information, services, goods, and money. Therefore, if information is disconnected between actors in the supply chain, it will lead to negative effects on the management of the entire supply chain. On the other hand, if supply chain actors can share information efficiently in real time on one platform, they can expect to optimize the entire supply chain. Information sharing and integration at the strategic and operational levels play a vital role in supply chain integration, which contributes to achieving a company's performance targets and enhancing its competitiveness.