• 제목/요약/키워드: Hybrid evaluation

Search Result 957, Processing Time 0.023 seconds

Analysis and Evaluation of DBMS Bulk Data Loading Through Multi-tiered Architecture for Heterogeneous Systems (이기종 시스템에서 다층 구조를 통한 DBMS 대용량 데이터 로딩의 분석 및 평가)

  • Tan, Hee-Yuan;Lim, Hyo-Taek
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.14 no.1
    • /
    • pp.167-176
    • /
    • 2010
  • Managing the growing number of data generated through various processes requires the aid of Database Management System (DBMS) to efficiently handle the huge amount of data. These data can be inserted into database m real time or in batch, that come from multiple sources, including those that are coming from inside and outside of a network. The insertion of large amount of data is commonly done through specific bulk loading or insertion function supplied by each individual DBMS. In this paper, we analyze and evaluate on handling data bulk loading for heterogeneous systems that is organised as multi-tiered architecture and compare the result of DBMS bulk loader against program insertion from a software development perspective. We propose a hybrid solution using staging database that can be easily deployed for enhancing bulk loading performance compared to insertion by application.

Evaluation of Adhesiveness with Current Flow Time in the Indirect Heating of an Asphalt Pad using Joule Heating (줄 히팅을 이용한 아스팔트패드 간접가열에 있어서 통전시간별 융착성 평가)

  • Bae, Ki-Man;Choi, Han-Suk;Oh, Bo-Ra-Mi;Baek, Jong-Jin;Park, Seong-Hwan;Kang, Myungchang;Lee, Jae-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.19 no.8
    • /
    • pp.104-109
    • /
    • 2020
  • Recently, vibration and noise have become an important issue in the auto industry. Asphalt vibration damping pads are used to reduce the noise and vibration of automobile bodies, and asphalt is used for many mass-produced parts due to its simple attachment process and low processing costs. In this study, the self-adhesion of asphalt pads using Joule heating was evaluated. To create the asphalt pad for the experiment, the asphalt pad was molded into a specific thickness by using SGACC material and rubber used in the vehicle body as a main component and a modified resin and filler. The SGACC material was 200 mm in length, 200 mm in width, and 0.7 mm in thickness. The asphalt pad was 200 mm in length, 100 mm in width, and 3 mm in thickness. The equipment was composed of a TR (Transformer) DC254kVA and a TC (Time controller) for a current of up to 20,000 A. The current for the Joule heating was set to 7.0 kA and a 3/1 cycle, for which the adhesion of the asphalt pad over the current flow time was evaluated.

The Study on Analysis of the effect of introducing Bimodal Tram - Comparing with BRT - (바이모달 트램 도입 효과 분석에 관한 연구 - BRT와의 비교분석을 중심으로-)

  • Jang, Jun-Seok;Lee, Jun;Eom, Jin-Ki
    • Proceedings of the KSR Conference
    • /
    • 2010.06a
    • /
    • pp.739-744
    • /
    • 2010
  • As recent traffic policy focuses on reduction of congestion and environmental contamination, with a catch phrase, 'Green Traffic', Low Carbon Green Growth' and 'Sustainable Development', introducing the new eco-friendly transport means including railway has been emerging as critical issue. Included in the new transport means are BRT, Bimodal Tram and LRT, and this study was intended to evaluate and analyze Bimodal, among others, which generates less emission, noise and vibration thanks to hybrid type traction system employed by Bimodal Tram, which is considered a future-oriented system because of eco-friendly features and cost efficiency as well as punctuality and convenient accessibility to bus. Thus in this study, appropriateness of Bimodal Tram comparing to other system(BRT) was suggested, using conversion traffic from the road, traffic speed and CO2 emission at the metropolitan area and large provincial areas as the barometer in evaluation, and furthermore, the measures applicable to introduction strategy that will meet various functional aspects in urban area in the coming days were developed.

  • PDF

Analytical Evaluation of FFR-aided Heterogeneous Cellular Networks with Optimal Double Threshold

  • Abdullahi, Sani Umar;Liu, Jian;Mohadeskasaei, Seyed Alireza
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.11 no.7
    • /
    • pp.3370-3392
    • /
    • 2017
  • Next Generation Beyond 4G/5G systems will rely on the deployment of small cells over conventional macrocells for achieving high spectral efficiency and improved coverage performance, especially for indoor and hotspot environments. In such heterogeneous networks, the expected performance gains can only be derived with the use of efficient interference coordination schemes, such as Fractional Frequency Reuse (FFR), which is very attractive for its simplicity and effectiveness. In this work, femtocells are deployed according to a spatial Poisson Point Process (PPP) over hexagonally shaped, 6-sector macro base stations (MeNBs) in an uncoordinated manner, operating in hybrid mode. A newly introduced intermediary region prevents cross-tier, cross-boundary interference and improves user equipment (UE) performance at the boundary of cell center and cell edge. With tools of stochastic geometry, an analytical framework for the signal-to-interference-plus-noise-ratio (SINR) distribution is developed to evaluate the performance of all UEs in different spatial locations, with consideration to both co-tier and cross-tier interference. Using the SINR distribution framework, average network throughput per tier is derived together with a newly proposed harmonic mean, which ensures fairness in resource allocation amongst all UEs. Finally, the FFR network parameters are optimized for maximizing average network throughput, and the harmonic mean using a fair resource assignment constraint. Numerical results verify the proposed analytical framework, and provide insights into design trade-offs between maximizing throughput and user fairness by appropriately adjusting the spatial partitioning thresholds, the spectrum allocation factor, and the femtocell density.

Fabrication of nano/micro hybrid compositesusing a discharge flocking device (방전식모 장치를 이용한 나노/마이크로 하이브리드 복합재 제조)

  • Lee, Byung-Kon;Lee, Hak-Gu;Lee, Sang-Bok;Lee, Won-Oh;Yi, Jin-Woo;Um, Moon-Kwang;Kim, Byung-Sun;Byun, Joon-Hyung
    • Composites Research
    • /
    • v.23 no.3
    • /
    • pp.13-18
    • /
    • 2010
  • One of the biggest challenges in the nano-field is how to effectively disperse nano-scale particles, especially CNTs, which are strongly agglomerated by intermolecular van der Waals forces. This study suggests a new method, discharge flocking, in order to disperse nano-scale particles effectively, which combines corona discharge phenomenon and a traditional electrostatic flocking process. In order to evaluate the discharge flocking process, composite specimens were fabricated by the process and RFI(resin film infusion) process, and then the mechanical and electrical properties of the specimens were measured and compared. Moreover, the evaluation of gas discharge effect on the CNTs and epoxy was performed to compare the mechanical and electrical properties of the composite specimens including the plasma treated CNTs. The experimental results showed that the electrical and mechanical properties of the specimens fabricated by the discharge flocking process were similar to those of the RFI process. In addition, plasma treated CNTs were not affected by gas discharge during the discharge flocking process.

Analysis of Research Trends for BrIC Injury (BrIC 상해에 대한 경향 분석 및 고찰)

  • Lee, Kihwang;Kim, Kiseok;Yoon, Ilsung
    • Journal of Auto-vehicle Safety Association
    • /
    • v.8 no.4
    • /
    • pp.12-17
    • /
    • 2016
  • NHTSA (National Highway Traffic Safety Administration) has offered consumers the vehicle safety information on their car since 1978. NHTSA believes that they contribute auto makers to develop safer vehicle for customers, which will result in even lower numbers of deaths and injuries resulting from motor vehicle crashes. NHTSA has been studied why people are still dying in frontal test despite of the use of many restraints system and they understand that current test does not reflect real world crash data such as oblique and corner impact test. As a result, NHTSA announced that a new test method will be introduced to use of enhanced biofidelic dummy and new crash avoidance technology evaluation from 2019. New and refined injury criteria will be applied to Head / Neck / Chest / Lower Leg. BrIC(Brain Injury Criterion)value in NHTSA test results using THOR dummy from 2014 to 2015 was average 0.91 and 1.24 in driver and passenger dummies. IIHS 64kph SOF test is the most likely to new frontal oblique test in an aspect of offset impact which is being studied by NHTSA. In this paper, we focused on head injury, especially brain injury - BrIC and conducted IIHS 64kph SOF (Small Offset Front) test with Hybrid III dummy to evaluate the injury for BrIC. Based on the test results, these data can be predicted BrIC level and US NCAP rating with current vehicle.

Ground Test and Performance Evaluation of Miniaturized AHRS for Small-Scale UAV (소형무인항공기를 위한 소형 경량 AHRS의 지상시험 및 성능 평가)

  • Roh, Min-Shik;Song, Jun-Beom;Song, Woo-Jin;Kang, Beom-Soo
    • Journal of Advanced Navigation Technology
    • /
    • v.15 no.2
    • /
    • pp.181-188
    • /
    • 2011
  • A small UAVs(Unmaned Aerial Vehicles) have limited by the payload capacity which requires miniaturization of a navigation system. In this paper, the performance of the lightweight and small sized AHRS(Attitude Heading Reference System), which is self-developed, is evaluated at low acceleration environment. The designed AHRS adopts the commercial low-cost MEMS sensors. A quaternion-based attitude calculation method, which eliminates singularity with relatively simple algebra, is used. In an attitude correction algorithm, the Kalman filter is used with accelerometers and magnetometers combined. The fabricated AHRS is also evaluated with reference to a COTS(Commercial Off-The-Shelf) AHRS which reports a number of successful applications to a small UAVs. The test results show that the measurements from the fabricated AHRS provide proper attitude output data with acceptable amount of differences(horizontal axis 0.5$^{\circ}$, vertical axis 1.5$^{\circ}$) in test environment.

An Architecture and Performance Evaluation of RDCDN (Re-Distribution based CDN) (콘텐츠 재분배 기능을 갖는 CDN(Content Delivering Network) 구조 및 특성)

  • Sung, Moo-Kyung;Han, Chi-Moon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.34 no.6B
    • /
    • pp.559-567
    • /
    • 2009
  • Distributed Content Delivering Network (DCDN) will make use of the existing resources of the common Internet users in terms of storage space, bandwidth and Internet connectivity to create it. However DCDN has some limitations that are inefficient using of storage space, reliability and having special load balancing (LB) algorithm. So, this paper proposes Re-distribution based CDN (RDCDN) that overcomes the limitations of DCDN. RDCDN has the content re-distribution algorithm and separates surrogates to main surrogate and sub surrogates. Main surrogate can help service reliability be improved by storing all contents as back-up system. And content re-distribution algorithm also can help storage space be saved because all contents are not stored in every surrogate. Especially, when RDCwDN uses content re-distribution algorithm, it can work active load balancing function without extra LB algorithm like as DCDN. Results of simulation show that the proposed architecture can improve reliability and efficiency of storage space, and it also can offer the same performance as that of commercial CDN and DCDN.

Manufacturing and Evaluation of the Properties of Hybrid Bulk Material by Shock-compaction of Nanocrystalline Cu-Ni Mixed Powder (나노 구리-니켈 혼합분말의 충격압축법을 통한 복합벌크재의 제조 및 특성평가)

  • Kim, Wooyeol;Ahn, Dong-Hyun;Park, Lee Ju;Kim, Hyoung Seop
    • Journal of Powder Materials
    • /
    • v.21 no.3
    • /
    • pp.196-201
    • /
    • 2014
  • In this study, nanocrystalline Cu-Ni bulk materials with various compositions were cold compacted by a shock compaction method using a single-stage gas gun system. Since the oxide layers on powder surface disturbs bonding between powder particles during the shock compaction process, each nanopowder was hydrogen-reduced to remove the oxide layers. X-ray peak analysis shows that hydrogen reduction successfully removed the oxide layers from the nano powders. For the shock compaction process, mixed powder samples with various compositions were prepared using a roller mixer. After the shock compaction process, the density of specimens increased up to 95% of the relative density. Longitudinal cross-sections of the shock compacted specimen demonstrates that a boundary between two powders are clearly distinguished and agglomerated powder particles remained in the compacted bulk. Internal crack tended to decrease with an increase in volumetric ratio of nano Cu powders in compacted bulk, showing that nano Cu powders has a higher coherency than nano Ni powders. On the other hand, hardness results are dominated by volume fraction of the nano Ni powder. The crystalline size of the shock compacted bulk materials was greatly reduced from the initial powder crystalline size since the shock wave severely deformed the powders.

Greenhouse Evaluation of Melon Rootstock Resistance to Monosporascus Root Rot and Vine Decline as Well as of Yield and Fruit Quality in Grafted 'Inodorus' Melons

  • Jang, Yoonah;Huh, Yun-Chan;Park, Dong-Kum;Mun, Boheum;Lee, Sanggyu;Um, Yeongcheol
    • Horticultural Science & Technology
    • /
    • v.32 no.5
    • /
    • pp.614-622
    • /
    • 2014
  • Melons (Cucumis melo L.) are generally grafted onto Cucurbita rootstocks to manage soilborne pathogens such as Monosporascus root rot and v ine decline (MRR/VD) and Fusarium wilt. However, g rafting onto Cucurbita rootstocks reportedly results in the reduction of fruit quality. In this study, the resistance to MRR/VD, yield, and fruit quality of melons grafted onto melon rootstocks were evaluated under greenhouse conditions. Eight melon rootstocks (R1 to R8) were used and the inodorus melon 'Homerunstar' was used as scion. Melon rootstocks R1 to R6 were selected based on resistance to MRR/VD under greenhouse conditions. Non-grafted 'Homerunstar' and plants grafted onto squash interspecific hybrid 'Shintozwa' rootstock (Cucurbita maxima D. ${\times}$ C. moschata D.) served as controls. Grafted melons were cultivated in the greenhouse infested with Monosporascus cannonballus during two growing seasons (summer and autumn). The responses to MRR/VD, yield, and fruit quality differed depending on the rootstocks and growing season. The melons grafted onto 'Shintozwa' exhibited less severe disease symptoms and higher survival rates than non-grafted melons in both seasons. While the melon rootstocks in the summer cultivation did not increase the survival rate compared to non-grafted melons, the melon rootstocks R1 and R2 in the autumn cultivation led to higher survival rates. The melon rootstocks resistant to MRR/VD increased the percentage of marketable fruits and marketable yields. Grafting onto the melon rootstocks caused little or no reduction of fruit quality such as low calcium content, fruit softening, and vitrescence, especially in lower-temperature autumn season. Accordingly, these results suggest that grafting onto the melon rootstocks may increase the tolerance to MRR/VD and the marketable yield without a reduction of fruit quality.