• Title/Summary/Keyword: lifespan

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Hematological change in mice injected with radiosensitizer and irradiated with high-dose radiation (증감약제를 투여한 마우스에 고에너지 방사선 조사 후 혈액학적 변화에 관한 연구)

  • Jung, Myo-Young;Ji, Yeon-Sang;Dong, Kyung-Rae
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.1136-1140
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    • 2009
  • The current population of elderly is increasing and the with an extended average lifespan, the frequency of cancerous occurrences have also increased, with these increases and the increase in radiotherapy for cancer patients, recognitions of harm and importance have become known. This article was known tumor treatment of patients with hematopoietic disorder by doing a comparative study on the changes in blood cells caused by the acute effects of trace dose to high dose of radiation exposed to mice. According to the sensitizer injection may give rise to harm to the components of peripheral blood. This material needs to be considered when for treating tumor patients and the risks of hematopoietic harm and believe that radiation therapy will be reasonable.

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Designing Hybrid HDD using SLC/MLC combined Flash Memory (SLC/MLC 혼합 플래시 메모리를 이용한 하이브리드 하드디스크 설계)

  • Hong, Seong-Cheol;Shin, Dong-Kun
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.7
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    • pp.789-793
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    • 2010
  • Recently, flash memory-based non-volatile cache (NVC) is emerging as an effective solution to enhance both I/O performance and energy consumption of storage systems. To get significant performance and energy gains by NVC, it would be better to use multi-level-cell (MLC) flash memories since it can provide a large capacity of NVC with low cost. However, the number of available program/erase cycles of MLC flash memory is smaller than that of single-level-cell (SLC) flash memory limiting the lifespan of NVC. To overcome such a limitation, SLC/MLC combined flash memory is a promising solution for NVC. In this paper, we propose an effective management scheme for heterogeneous SLC and MLC regions of the combined flash memory.

Effects of membrane orientation on permeate flux performance in a submerged membrane bioreactor

  • Lee, Tsun Ho;Young, Stephanie
    • Membrane and Water Treatment
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    • v.3 no.3
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    • pp.141-149
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    • 2012
  • The aeration provided in a Submerged Membrane Bioreactor (SMBR) improves membrane filtration by creating turbulence on the membrane surface and reducing membrane resistance. However, conventional hollow fiber membrane modules are generally packed in a vertical orientation which limits membrane scouring efficiency, especially when aeration is provided in the axial direction. In the present research, 3 innovative hollow-fiber membrane modules, each with a different membrane orientation, were developed to improve membrane scouring efficiency and enhance permeate flux. Pilot testing was performed to investigate the permeate flux versus time relationship over a 7-day period under different intermittent modes. The results indicated that the best module experienced an overall permeate flux decline of 3.3% after 7 days; the other two modules declined by 13.3% and 18.3%. The lower percentage of permeate flux decline indicated that permeate productivity could be sustained for a longer period of time. As a result, the operational costs associated with membrane cleaning and membrane replacement could be reduced over the lifespan of the module.

Pre-Occupancy Evaluation Methodology of Housing Design for Elderly People (미래 노인주거환경 디자인을 위한 거주전 평가방법에 관한 연구)

  • Kim, Mi-Yun;Kim, Gun-Young;Choi, Jin-Won
    • 한국HCI학회:학술대회논문집
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    • 2008.02b
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    • pp.227-232
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    • 2008
  • Since 2000, there have been many changes in the residential types, such as an intelligent apartment which integrates both resting space and production space with comfort able, pleasant and safe environments based on internet systems. As the result of the rapid decrease in the birth rate and the prolonged lifespan around the world, it is expected that we will enter into an aging society by 2026. With such the expected change in the living patterns, many issues concerning the increased number of the elderly people have emerged as major social problems such as changes of family formation, its function and values, responsibility of caring for the aged, health and medical care, habitation policies and so on, and it is required to reconsider the social awareness on the living qualities of each old person. However, we have not yet satisfied such requirements with appropriate policies for the improvement of the living environment for them. It is considered, therefore, that we need to develop a new tool that, according to our goals, can give us a broad understanding on several considerations in designing the future homes for the elder people, making it possible to check the process changed by residents' needs in real time and apply it immediately to the space. As we have seen, it is required that spatial design process and design methodology should be considered in designing the homes for the aged for the pre-occupancy design evaluation.

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A Study on the Needs of the utilization and improvement of the multi-family housing residence (다가구.다세대주택 소유자의 주거환경 개선 및 활용 요구에 관한 연구)

  • Kim, Hye-Yeun;Lee, Young-Sun;Jang, Mi-Seon;Lee, Yeun-Sook
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.11a
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    • pp.135-139
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    • 2008
  • Through the industrialization since 1960, Korean housing has been developed in a uniform way which is to demolish first and then construct from the scratch. In this process, detached houses and multi-family living detached houses have disappeared without being paid much attention. The detached houses with blood or non-blood related multi-family living situations are typically popular, and worthy enough to explore for professionals right and creative solutions to enhance their values. But many of the people suffered for the expenses and the absence of the idea to enhance their housing themselves. The purpose of this research is to clarify user's demands of developing an adaptable lifespan house and to try to find the solution about the expenses of self improvement. This study used a Small group workshop Panel Method. The workshop consisted of three stage, such as the awareness of their existing residence and lease status, the needs of the housing improvements and the demands of the adaptable house. This study is expected to serve as a fundamental data to promote discussion on reuse of existing residence building and to promote rental detached houses.

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Mobile Sensor Relocation to Prolong the Lifetime of Wireless Sensor Networks (무선 센서망의 수명 연장을 위한 센서 재배치)

  • Yoo, Young-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.4B
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    • pp.338-348
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    • 2009
  • The Wireless Sensor Network (WSN) has recently attracted considerable attention due to the low price and ease to deploy it. In particular, in a hostile or harsh regions where sensors cannot be deployed manually, WSNs can be established just by dropping sensors from the air. In this case, however, most likely sensors are not placed at optimal positions, although the location of sensors does have a drastic impact on the WSN performance. Moreover, randomized deployment algorithm can leave holes in terms of coverage in the sensing area. This paper proposes a sensor relocation scheme where mobile sensors move to patch up the holes by appropriate coverage. Simulation results show that the proposed algorithm outperforms prior existing schemes in terms of coverage and lifespan of WSNs.

Novel Ignition Method for Automotive HID lamp Ballast System (자동차 헤드라이트용 고압방전등 안정기 시스템의 새로운 점등방식)

  • Kim, Yoon-Ho;Um, Tae-Wook;Lee, Jae-Hak
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.4
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    • pp.238-243
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    • 2006
  • This paper presents novel ignition method for automotive 35W metal halide discharge lamp electronic ballast. At this study, the novel method of ignition is developed to reduce costs and size of the ballast. By use of the novel method, the voltage needed in ignition is decreased, which result in use of the lower voltage rating power devices compared with conventional method and product compactness was achieved by deleting a circuit generating negative voltage needed in ignition at an conventional circuit. In terms of luminosity, color rendering, light efficiency(lm/W) and lifespan, the metal halide lamp is superior to, but unlike halogen lamp, it have more complicated transient characteristics to reach its steady state than the conventional halogen lamp. Therefore, in this paper, the electronic ballast was designed such that the metal halide lamp could be optimized for the automotive, by applying a method of microcontroller-based digital control. The results of the proposed system is verified through various experiment results.

Efficient Approach for Maximizing Lifespan in Wireless Sensor Networks by Using Mobile Sinks

  • Nguyen, Hoc Thai;Nguyen, Linh Van;Le, Hai Xuan
    • ETRI Journal
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    • v.39 no.3
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    • pp.353-363
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    • 2017
  • Recently, sink mobility has been shown to be highly beneficial in improving network lifetime in wireless sensor networks (WSNs). Numerous studies have exploited mobile sinks (MSs) to collect sensed data in order to improve energy efficiency and reduce WSN operational costs. However, there have been few studies on the effectiveness of MS operation on WSN closed operating cycles. Therefore, it is important to investigate how data is collected and how to plan the trajectory of the MS in order to gather data in time, reduce energy consumption, and improve WSN network lifetime. In this study, we combine two methods, the cluster-head election algorithm and the MS trajectory optimization algorithm, to propose the optimal MS movement strategy. This study aims to provide a closed operating cycle for WSNs, by which the energy consumption and running time of a WSN is minimized during the cluster election and data gathering periods. Furthermore, our flexible MS movement scenarios achieve both a long network lifetime and an optimal MS schedule. The simulation results demonstrate that our proposed algorithm achieves better performance than other well-known algorithms.

Study on CNC plasma-cutting worktable with improved lifetime (CNC 플라즈마 절단 작업테이블의 수명 향상에 관한 연구)

  • Na, Yeong-min;Lee, Hyun-seok;Kang, Tae-hun;Park, Jong-kyu
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.14 no.3
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    • pp.112-123
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    • 2015
  • There are many systems for cutting plates or pipes into a desired shape. A typical system is a plasma cutter. It uses plasma, which means that an effective design of the table supporting the workpiece is an important issue in order to ensure a long operational career. Conventional roller-support worktables have a short lifespan due to scratches from the plasma, and it is also difficult to maintain the roller balance. By using a bolt-fastening method, deformation and failure of the final product can occur due to the stress concentration at bolting points. To escape these issues, a polygon support and bracket fastening method was designed. Due to polygons having a number of support surfaces, when one surface has been damaged, it is possible to reuse the support by utilizing a different surface. The bracket-fastening method can extend the worktable lifetime and increase productivity by reducing stress concentration. In this paper, the polygon support/bracket-fastening method is compared with existing technologies. Consequently, performance benchmarks are verified through a structure analysis and experimentation.

Nicotinamide Exerts Antioxidative Effects on Senescent Cells

  • Kwak, Ju Yeon;Ham, Hyun Joo;Kim, Cheol Min;Hwang, Eun Seong
    • Molecules and Cells
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    • v.38 no.3
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    • pp.229-235
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    • 2015
  • Nicotinamide (NAM) has been shown to suppress reactive oxygen species (ROS) production in primary human fibroblasts, thereby extending their replicative lifespan when added to the medium during long-term cultivation. Based on this finding, NAM is hypothesized to affect cellular senescence progression by keeping ROS accumulation low. In the current study, we asked whether NAM is indeed able to reduce ROS levels and senescence phenotypes in cells undergoing senescence progression and those already in senescence. We employed two different cellular models: MCF-7 cells undergoing senescence progression and human fibroblasts in a state of replicative senescence. In both models, NAM treatment substantially decreased ROS levels. In addition, NAM attenuated the expression of the assessed senescence phenotypes, excluding irreversible growth arrest. N-acetyl cysteine, a potent ROS scavenger, did not have comparable effects in the tested cell types. These data show that NAM has potent antioxidative as well as anti-senescent effects. Moreover, these findings suggest that NAM can reduce cellular deterioration caused by oxidative damage in postmitotic cells in vivo.