• Title/Summary/Keyword: Cold Data

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Analysis of Spatial Control System in Cold-Rolling thru Web-based Remote Monitoring (Web기반의 원격모니터링을 통한 냉간 압연의 공간제어 시스템 해석)

  • 최승현;임준홍
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.183-183
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    • 2000
  • In this paper, web-based remote monitoring for cold-rolling system is developed and the analysis of spatial control system is performed. The remote monitoring system is able to grasp the status of cold-rolling system regardless of time and locations. We analyzed spatial control algorithm of the system with the collected data. The usefulness of spatial control system is shown by simulation studies.

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Addressing the Item Cold-Start in Recommendation Using Similar Warm Items (유사 아이템 정보를 이용한 콜드 아이템 추천성능 개선)

  • Han, Jungkyu;Chun, Sejin
    • Journal of Korea Multimedia Society
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    • v.24 no.12
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    • pp.1673-1681
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    • 2021
  • Item cold start is a well studied problem in the research field of recommender systems. Still, many existing collaborative filters cannot recommend items accurately when only a few user-item interaction data are available for newly introduced items (Cold items). We propose a interaction feature prediction method to mitigate item cold start problem. The proposed method predicts the interaction features that collaborative filters can calculate for the cold items. For prediction, in addition to content features of the cold-items used by state-of-the-art methods, our method exploits the interaction features of k-nearest content neighbors of the cold-items. An attention network is adopted to extract appropriate information from the interaction features of the neighbors by examining the contents feature similarity between the cold-item and its neighbors. Our evaluation on a real dataset CiteULike shows that the proposed method outperforms state-of-the-art methods 0.027 in Recall@20 metric and 0.023 in NDCG@20 metric.

The Significant Decisions in Cold Chain Logistics

  • Sung-Ho, RYU
    • East Asian Journal of Business Economics (EAJBE)
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    • v.11 no.1
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    • pp.41-51
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    • 2023
  • Purpose - The prior literature has shown that there is a lack of a complete assessment of the key decisions in cold chain logistics. Such a study is required to offer recommendations for research in this expanding but under-researched topic with potentially significant management ramifications. Research design, Data, and methodology - The current researcher accumulated peer-reviewed sources from databases to augment each chosen study's validity. Selection varied between seminal works and much of the existing literature. The selection process was consistent with using a content checklist that established the inclusion and exclusion criteria. Result - The research findings indicate total five solutions regarding better decision in Cold Chain Logistics (CCL), such as (1) Pricing Decision in Cold Chain Logistics, (2) Decision on Temperature Control Decision in Cold Chain Logistics, (3) Supply Chain Network Design in Cold Chain Logistics, (4) Decision on Minimizing Inventory in Cold Chain Logistics, (5) Decision on Logistics Distribution. Conclusion - Stability of a cold chain should be maintained from manufacture or via logistical components and cold logistics products are susceptible to several variables, such as temperature, and degradation can easily harm food supply, product prices, and human health. Product safety infractions substantially impact human health, among other losses linked with a functioning CCL.

Cold Data Identification using Raw Bit Error Rate in Wear Leveling for NAND Flash Memory

  • Hwang, Sang-Ho;Kwak, Jong Wook;Park, Chang-Hyeon
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.12
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    • pp.1-8
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    • 2015
  • Wear leveling techniques have been studied to prolong the lifetime of NAND flash memory. Most of studies have used Program/Erase(P/E) cycles as wear index for wear leveling. Unfortunately, P/E cycles could not predict the real lifetime of NAND flash blocks. Therefore, these algorithms have the limited performance from prolonging the lifetime when applied to the SSD. In order to apply the real lifetime, wear leveling algorithms, which use raw Bit Error Rate(rBER) as wear index, have been studied in recent years. In this paper, we propose CrEWL(Cold data identification using raw Bit error rate in Wear Leveling), which uses rBER as wear index to apply to the real lifetime. The proposed wear leveling reduces an overhead of garbage collections by using HBSQ(Hot Block Sequence Queue) which identifies hot data. In order to reduce overhead of wear leveling, CrEWL does not perform wear leveling until rBER of the some blocks reaches a threshold value. We evaluate CrEWL in comparison with the previous studies under the traces having the different Hot/Cold rate, and the experimental results show that our wear leveling technique can reduce the overhead up to 41% and prolong the lifetime up to 72% compared with previous wear leveling techniques.

Analysis and Improvement of Cooling System for Energy Saving in Data Center Building (데이터센터의 냉방에너지 절감을 위한 냉각시스템 분석 및 개선 방안)

  • Jung, Yong-Ho
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.314-319
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    • 2011
  • Energy Cost has been rapidly increased with the internal heat gain of data center to keep the temperature condition. But the cooling units for server systems are fully operated to satisfy the indoor temperature condition, it results in the excessive energy consumption. In this study, various cooling systems were studied for data center and cold aisle containment system was proved to be the best solution for server cooling system. Because it protects the cooling zone from the hot aisle space. Effective cooling and prohibition of recirculation air from hot aisle was possible by the cold aisle containment system.

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Development of probabilistic primary water stress corrosion cracking initiation model for alloy 182 welds considering thermal aging and cold work effects

  • Park, Jae Phil;Yoo, Seung Chang;Kim, Ji Hyun;Bahn, Chi Bum
    • Nuclear Engineering and Technology
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    • v.53 no.6
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    • pp.1909-1923
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    • 2021
  • We experimentally investigated the effects of thermal aging and cold work on the microstructure, mechanical properties, and primary water stress corrosion cracking (PWSCC) initiation time for Alloy 182 welds. The effects of thermal aging and cold work on the PWSCC initiation time of Alloy 182 were modeled based on the plastic energy concept and the PWSCC initiation data of this study and previous reports by considering censored data. Based on the results, it is estimated that the PWSCC resistance of the Alloy 182 weld firstly increases and then decreases with thermal aging time when the applied stress is kept constant.

A Wear-leveling Scheme for NAND Flash Memory based on Update Patterns of Data (데이터 갱신 패턴 기반의 낸드 플래시 메모리의 블록 사용 균일화 기법)

  • Shin, Hyo-Joung;Choi, Don-Jung;Kim, Bo-Keong;Yoon, Tae-Bok;Lee, Jee-Hyong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.6
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    • pp.761-767
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    • 2010
  • In the case of NAND flash memory, a whole block needs to be erased for update operations because update-in- place operations are not supported in NAND flash memory. Blocks of NAND flash memory have the limited erasure cycles, so frequently updated data (hot data) easily makes blocks worn out. As the result, the capacity of NAND flash memory will be reduced by hot data. In this paper, we propose a wear-leveling algorithm by discriminating hot and cold data based on the update patterns of data. When we applied this scheme to NAND flash memory, we confirmed that the erase counts of blocks became more uniform by mapping hot data to a block with a low erase count and cold data to block with a high erase count.

Cold Perception Responses according to Body Parts and Wearing Behaviors of College Students (대학생의 신체부위별 추위지각 반응과 착의 행동)

  • Zhang, Chong;Jun, Dae Geun;Jeong, Woon Seon
    • The Korean Journal of Community Living Science
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    • v.26 no.4
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    • pp.775-783
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    • 2015
  • This study investigates gender differences in cold perceptions and wearing behaviors for cold adaptation. A questionnaire composed of items on cold perceptions, intentions toward wearing additional clothing, and clothing for outdoor environments, among others, was used. Each item in the survey targeted 260 male (MS) and female (FS) college students evaluated using a five-point Likert-type scale. Data were statistically analyzed using the independent sample t-test and correlations. Main results can be summarized as follows: MS subjects showed lower dependence on the thermal insulation of clothing because they felt less cold and had the better ability to cope with cold. MS subjects had higher dependence on underwear during cold seasons, and FS subjects tended to wear heavier clothing to compensate for their cold feet with insufficient insulation. In addition, it was preferable to estimate thermal effects of actual wear by taking into account gender differences in the physique. The study is limited in that the room temperature and the actual amount of clothing were not measured, which offers an avenue for future research.

Research on cold-formed steel connections: A state-of-the-art review

  • Qin, Ying;Chen, Zhihua
    • Steel and Composite Structures
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    • v.20 no.1
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    • pp.21-41
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    • 2016
  • Cold-formed steel structures are increasingly attractive due to their benefits of good mechanical performance and constructional advantages. However, this type of construction is still not fully exploited as a result of the acknowledged difficulties involved in forming construction-efficient and cost-effective connections. Furthermore, there is a lack of information on the structural behavior of the cold-formed steel connections. In this study, the research on various cold-formed steel connections was comprehensively reviewed from both fundamental and structural points of view, based on the available experimental and analytical data. It reveals that the current design codes and guidelines for cold-formed steel connections tend to focus more on the individual bearing capacity of the fasteners rather than the overall structural behavior of the connections. Significant future work remains to be conducted on the structural performance of cold-formed steel connection. In addition, extensive previous research has been carried out to propose and evaluate an economical and efficient connection system that is obtained from the conventional connecting techniques used in the hot-rolled industry. These connecting techniques may not be suitable, however, as they have been adopted from hot-rolled steel portal frames due to the thinness of the sheet in cold-formed steels. The review demonstrates that with the increasing demand for cold-formed steel constructions throughout the world, it is crucial to develop an efficient connection system that can be prefabricated and easily assembled on site.

The Agreement in Cold-Heat and Health Status among Sasang Constitutional Experts in Diagnosis of Sasang Pathological Symptoms (사상의학 병증진단에 있어서 사상의학 전문가의 한열 특성 및 건강상태 평가에 관한 일치도 연구)

  • Jin, Hee-Jeong;Kim, Sang-Hyuk;Dong, Sang-Oak;Jang, Eun-Su;Lee, Si-Woo
    • Journal of Sasang Constitutional Medicine
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    • v.26 no.2
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    • pp.146-155
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    • 2014
  • Objectives In Sasang Constitutional medicine(SCM), it is an important factor to assess the degree of cold/heat and healthy status. We purposed to check the agreement among the experts on the assessment of cold/heat and healthy status. Methods Six SCM experts and 10 healthy volunteers were recruited for this study. The SCM experts had an interviewed with each volunteer in the similar condition like that of the actual clinic. And then the expert evaluated each volunteer's cold/heat and healthy status. Intraclass correlation coefficient(ICC) was used to measure the interrater reliability and interrater agreement among the experts. Results Two volunteers are excluded due to the missing data, therefore eight persons' data (3 males and 5 females) were included in our analysis. The mean of age and BMI are 21.73(${\pm}2.32$) and 29.63(${\pm}4.66$), respectively. In health status, cold status and heat status, the ICC was 0.789, 0.904, 0.925, respectively. Conclusions We found that the assessment of cold/heat and healthy status was continued reliable among SCM experts. The assessment of cold/heat status was more consistent than the assessment of healthy status.