• 제목/요약/키워드: Turn Over

검색결과 713건 처리시간 0.023초

부정적 미래 상상과 그에 따른 부정성의 지연중성화 감소 (Imagining Negative Futures to Reduce the Delay Neutralization of Negativity)

  • 신연순;김혜영;한상훈
    • 감성과학
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    • 제16권3호
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    • pp.293-304
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    • 2013
  • Procrastination is an irrational choice to delay high-priority work in order to avoid its unpleasantness, despite the fact that the negativity will not cease if the work still remains undone. We hypothesized that (1) people underestimate the future negativity (i.e., delay neutralization) and (2) in order to complete work in a timely manner, one should project oneself into the future so as to recognize that the negativity associated with an activity does not diminish over time. Especially, negative future thinking that is unrelated to the consequence was hypothesized to reduce delay neutralization of negativity. In the present study, undergraduate students made a series of choices between delayed-but-longer and immediate-but-shorter assignment by employing an inter-temporal choice paradigm. We tracked how positive and negative episodic future thinking influenced the degree to which negativity is neutralized over time (Experiment 1). Following this, we confined the experimental condition to negative thinking about the future (Experiment 2). Participants neutralized negativity involved in assignment as a function of time, suggesting that procrastination arises from the delay neutralization of the negativity. Critically, such neutralization was significantly reduced when participants imagined a negative future event, but this did not occur when they imagined a positive future event (Experiment 1), or when participants did not think about the future (Experiment 1, 2). Our findings suggest that, prior to making a decision between work and indulgence, imagining negative future events can be an effective way to reduce the neutralization of delayed negativity and, in turn, procrastination.

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Photocatalytic Oxidation of 2-Mercaptoethanol to Disulfide using Sb(V)-, P(V)-, and Ge(IV)-porphyrin Complexes

  • Shiragami, Tsutomu;Onitsuka, Dai;Matsumoto, Jin;Yasuda, Masahide
    • Rapid Communication in Photoscience
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    • 제3권4호
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    • pp.70-72
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    • 2014
  • Visible-light irradiation of MeCN solution containing di(hydroxo)metallo(tetraphenyl)porphyrin complex $(tppM(OH)_2$: 1a; $M=Sb(V)^+Br^-$, 1b; $M=P(V)^+Cl^-$, 1c; M=Ge(IV)) and 2-mercaptoethanol (2-ME) as a substrate under aerated condition gave bis(2-hydroxyethyl)disulfide (2-HEDS) as an oxidative product of 2-ME. It is indicated that the oxidation of 2-ME should proceed with a photocatalytic process by 1, because the turn over number (TON) for the formation of 2-HEDS was over unit. The TON was determined to be 642 as a maximum value when 1a was used as a sensitizer. The formation of 2-HDES was extremely slow under argon atmosphere. The fluorescence of 1 was not quenched by 2-ME at all, and the free energy change (${\Delta}G$) with electron transfer (ET) from 2-ME to excited triplet state of $1(^31^*)$ was estimated as a negative value. The quenching rate constant ($k_r$) of $^31^*$ by 2-ME, obtained by the kinetics for the formation of 2-HEDS, strongly depends on ${\Delta}G$. These findings indicate that 1-sensitized oxidation was initiated by photoinduced ET from 2-ME to $^31^*$ to generate both radical cation of 2-ME ($2-ME^{+\bulle}$) and porphyrin radical anion ($1^{-\bulle}$), resulting that the formation of 2-HEDS can be proceeded by the dimerization of $2-ME^{+\bulle}$, and through a catalytic cycle due to returning to 1 by the ET from $1^{-\bulle}$ to molecular oxygen.

폴리프로필렌 섬유보강 화강토 콘크리트의 역학적 특성 (Mechanical Properties of Granite Soil Concrete with Polypropylene Fiber)

  • 남기성;전형순
    • 한국농공학회논문집
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    • 제55권1호
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    • pp.1-8
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    • 2013
  • This study will not only prove experimental dynamic properties which are classified to slump, compressive strength, tensile strength, flexure strength and toughness granite soil concrete with a fine aggregate of granite soil and blast-furnace cement and polypropylene fiber over 45 mm, but also establish a basic data in order to use environment-friendly pavement through prove useful pavement mixed with granite and polypropylene (PP) fiber which is a kind of material to prevent a dry shrinkage clack, a partial destruction and useful and light. The value of slump test was gradually increased by PP fiber volume 3 $kgf/m^3$, but compressive strength took a sudden turn for the worse from 5 $kgf/m^3$. The compressive strength indicated a range of 13.72~18.35 MPa. On the contrary to compressive strength, the tensile strength showed to decrease with rising PP fiber volume, and the tensile strength indicated a range of 1.43~1.64 MPa. The tensile strength was stronger about 2~15 % in case of mixing with PP fiber volume than normal concrete. The flexural strength indicated a range of 2.76~3.41 MPa. The flexural strength was stronger about 20 % in case of PP fiber volume 0 $kg/m^3$ than PP fiber volume 9 $kg/m^3$. The toughness indicated a range of 0~25.46 $N{\cdot}mm$ and increased proportionally with PP fiber volume. The toughness was stronger about 8.3 times in case of PP fiber volume 9 $kg/m^3$ than PP fiber volume 1 $kg/m^3$. The pavement with PP fiber volume over such a fixed quantity in the park roads and walkways can have a effect to prevent not only resistance against clack but also rip off failures.

무 혈청배지에 의한 각막상피 세포의 세포고사 (The Induction of Human Corneal Epithelial Apoptosis by Serum-free Medium)

  • 나명석;김재민
    • 한국안광학회지
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    • 제4권1호
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    • pp.1-6
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    • 1999
  • 사람의 각막상피 세포를 배양하여 각막상피가 저절로 탈락해 나가는 과정을 이해하기 위해 무 혈청 배지에서 세포를 1주일 동안 배양하여 시간의 경과에 따른 세포의 소실과정을 조사하였다. 사람 각막상피 세포 주를 무 혈청 배지에서 배양하여 1, 2, 3, 6일에 세포의 형태적 관찰과 세포고사(Apoptosis) 정도를 측정하기 위해 Giemsa 염색, Hoechst 33342 형광 염색, 그리고 TUNEL(TdT-dUTP terminal nick-end labelling) assay를 시행하였다. 무 혈청 배지에서 세포를 배양하연 시간이 지남에 따라 세포의 모양이 변하였으며 망상의 세포 군집을 형성하였다. 많은 세포가 부유하여 작은 소체를 형성하였으며 세포고사 율은 3일 경과 후 50%를 나타냈다. 또한 TUNEL assay에 의해 단편화된 DNA도 관찰할 수 있었다. 본 연구의 결과는 영양 부족상태의 각막상피 세포가 세포고사를 거쳐 소모되고 탈락되는 것을 암시하고 있다.

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Integrated Environment Impact Assessment of Brick Kiln using Environmental Performance Scores

  • Pokhrel, Rajib;Lee, Heekwan
    • Asian Journal of Atmospheric Environment
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    • 제8권1호
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    • pp.15-24
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    • 2014
  • The capital city of Himalayan Country Nepal, Kathmandu Valley is surrounded by consecutive high mountains, which limits the air distribution and mixing effects significantly. It in turn generates steady air flow pattern over a year except in monsoon season. The air shed in the Valley is easily trapped by the surrounded mountains and the inversion layer formulated as the cap. The $PM_{10}$ concentration was noticeably higher than the standard level (120 ${\mu}g/m^3$) in urban and suburban area of Kathmandu valley for all seasons except monsoon period. The Valley area experiences similar wind patterns (W, WWS, and S) for a year but the Easterly wind prevails only during the monsoon period. There was low and calm wind blows during the winter season. Because of this air flow structure, the air emission from various sources is accumulated within the valley air, high level of air pollution is frequently recorded with other air polluted cities over the world. In this Valley area, brick kilns are recognized as the major air pollution source followed by vehicles. Mostly Bull Trench Kiln (BKT), Hoffman Kiln and Vertical Shaft Brick Kiln (VSBK) are in operation for brick firing in Kathmandu valley where the fuels such as crushed coal, saw dust, and natural gas are used for processing bricks in this study. Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) was used for screening and quantifying the potential impacts of air emission from firing fuels. The total Environmental Performance Score (EPS) was estimated and the EPS of coal was approximately 2.5 times higher than those of natural gas and saw dust. It is concluded that the crushed coal has more negative impact to the environment and human health than other fuel sources. Concerning the human health and environment point of view, alternative environment friendly firing fuel need to be used for brick industry in the kiln and the air pollution control devices also need to be applied for minimizing the air emissions from the kilns.

호주산 수출 생축 동물복지에 관한 조사 (Survey on animal welfare problems in Australian exporting live animals)

  • 장성준
    • 한국동물위생학회지
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    • 제29권2호
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    • pp.129-154
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    • 2006
  • Last year, over 800 Australian live cattle were imported, underwent quarantine procedure for one month in the port of Incheon and Busan and distributed to general farm house holds in Gyeongju city, Gyeongbuk province, and Gimhae city, Namhae county, Gyeongnam province. But Hanwoo association took violent actions to prevent from entering the country for fear that the imported live cattle would destroy the 'Hanwoo industry', and in turn leads to the collapse of the industry. In Australia, national animal protection body 'Animals Australia' investigated the level of cruelty involved in this trade and made a report 'The death file'. Australia governments drive to expand Its market for 'live animal exports' and it has resulted in a corresponding increase In casualties associated with the long-haul overseas trade in live livestock animals over the past years. After the stress of transportation, all the surviving cattle and sheep face death on foreign soil, many into countries which have no animal welfare laws or, at best, inadequate laws. They will usually be killed without pre-stunning and often even without adequate restraint facilities. The result is inherent and persistent suffering. West Australian(WA) Police acting on behalf of the West Australian Government and the Office of the WA State Solicitor have laid animal cruelty charges against a leading WA live export company for breaching the WA Animal Welfare Act. With the aim of eventually substituting it for the live sheep trade, the Senate Select Committee on Animal Welfare (SCCAW) recommended that the Federal Government 'promote and encourage the expansion of the refrigerated sheep meat trade to the Middle East and other countries'. Animal welfare standards have been improved time after time, there is another incident, another public outcry, another inquiry and more assurances.

Force limited vibration testing: an evaluation of the computation of C2 for real load and probabilistic source

  • Wijker, J.J.;de Boer, A.;Ellenbroek, M.H.M.
    • Advances in aircraft and spacecraft science
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    • 제2권2호
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    • pp.217-232
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    • 2015
  • To prevent over-testing of the test-item during random vibration testing Scharton proposed and discussed the force limited random vibration testing (FLVT) in a number of publications. Besides the random vibration specification, the total mass and the turn-over frequency of the load (test item), $C^2$ is a very important parameter for FLVT. A number of computational methods to estimate $C^2$ are described in the literature, i.e., the simple and the complex two degrees of freedom system, STDFS and CTDFS, respectively. The motivation of this work is to evaluate the method for the computation of a realistic value of $C^2$ to perform a representative random vibration test based on force limitation, when the adjacent structure (source) description is more or less unknown. Marchand discussed the formal description of getting $C^2$, using the maximum PSD of the acceleration and maximum PSD of the force, both at the interface between load and source. Stevens presented the coupled systems modal approach (CSMA), where simplified asparagus patch models (parallel-oscillator representation) of load and source are connected, consisting of modal effective masses and the spring stiffness's associated with the natural frequencies. When the random acceleration vibration specification is given the CSMA method is suitable to compute the value of the parameter $C^2$. When no mathematical model of the source can be made available, estimations of the value $C^2$ can be find in literature. In this paper a probabilistic mathematical representation of the unknown source is proposed, such that the asparagus patch model of the source can be approximated. The chosen probabilistic design parameters have a uniform distribution. The computation of the value $C^2$ can be done in conjunction with the CSMA method, knowing the apparent mass of the load and the random acceleration specification at the interface between load and source, respectively. Data of two cases available from literature have been analyzed and discussed to get more knowledge about the applicability of the probabilistic method.

A Study on Relationship between Smartphone User Pattern and Addiction

  • Lee, Myung-Suk;Lim, Young-Kyu
    • 한국컴퓨터정보학회논문지
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    • 제23권3호
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    • pp.101-106
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    • 2018
  • The purpose of this study is to analyze the patterns of unconsciousness smartphone use by using an app and a self-administered survey on smartphone addiction comparatively and examine differences between recognition and behavior about actual smartphone use and examine how smartphone addiction influences learning. With an app installed in smartphones, this author collected and analyzed data about users' unconsciousness using patterns for a month. According to the results, there were significant differences found in users' recognition and actual time for use and also frequency of turning on the display. Also, 22% of the subjects used their smartphone over 8 hours a day, and 76% more than 5 hours. Over 95% turned on the display more than 100 times a day, and in extreme cases, they did more than 300 times. In the meantime, users not only in the smartphone addiction high risk group and the potential risk group but also in the general user group are found to use their smartphone too long and too much and frequently turn on the display. The apps that the general user group is mainly using are entertaining apps, and their school records are rather good, so excessive use does not always lead to addiction or learning disorder. Therefore, if we develop more diverse contents for learning and provide digital literacy education, smartphone use will bring more positive effects instead. In follow-up research, the app should be corrected to collect more accurate information, and as variables in personal areas, this researcher will also measure depression, anxiety, stress, self-esteem, and emotional control, and so on to see how they are associated with smartphone use.

수도권 초미세먼지 농도모사: ( I ) 2013 CAPSS 배출량 목록의 전구물질별 기여도 추정 (PM2.5 Simulations for the Seoul Metropolitan Area: ( I ) Contributions of Precursor Emissions in the 2013 CAPSS Emissions Inventory)

  • 김순태;배창한;김병욱;김현철
    • 한국대기환경학회지
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    • 제33권2호
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    • pp.139-158
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    • 2017
  • CMAQ (Community Multiscale Air Quality Model) simulations were carried out to estimate the potential range of contributions on surface $PM_{2.5}$ concentrations over the Seoul Metropolitan Area (SMA) with the gaseous precursors and Primary Particulate Matters(PPM) available from a recent national emissions inventory. In detail, on top of a base simulation utilizing the 2013 Clean Air Policy Supporting System (CAPSS) emission inventory, a set of Brute Force Method (BFM) simulations after reducing anthropogenic $NO_x$, $SO_2$, $NH_3$, VOCs, and PPM emissions released from area, mobile, and point sources in SMA by 50% were performed in turn. Modeling results show that zero-out contributions(ZOC) of $NH_3$ and PPM emissions from SMA are as high as $4{\sim}5{\mu}g/m^3$ over the region during the modeling period. On the contrary, ZOC of local $NO_x$ and $SO_2$ emissions to SMA $PM_{2.5}$ are less than $1{\mu}g/m^3$. Moreover, model analyses indicate that a wintertime $NO_x$ reduction at least up to 50% increases SMA $PM_{2.5}$ concentrations, probably due to increased HNO3 formation and conversion to aerosols under more abundant ozone and radical conditions after the $NO_x$ reduction. However, a nation-wide $NO_x$ reduction decreased SMA $PM_{2.5}$ concentrations even during winter, which implies that nation-wide reductions would be more effective to curtail SMA $PM_{2.5}$ concentrations than localized efforts.

PCMM 기반 특징 보상 기법에서 변별력 향상을 위한 Minimum Classification Error 훈련의 적용 (Minimum Classification Error Training to Improve Discriminability of PCMM-Based Feature Compensation)

  • 김우일;고한석
    • 한국음향학회지
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    • 제24권1호
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    • pp.58-68
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    • 2005
  • 본 논문에서는 잡음 환경에서 강인한 음성 인식을 위하여 특징 보상 기법의 성능을 향상시킬 수 있는 방법을 제안한다. 기존의 음성 모델 기반의 특징 보상 기법에서 이용되는 오염 음성 모델 추정 방식은 입력 음성에 대한 변별력 있는 사후 확률 예측을 보장하지 못하며, 부정확하게 계산된 사후 확률은 복구된 음성에서 명료도 하락의 문제를 일으킨다. 제안하는 기법에서는 오염 음성 모델 추정 과정에 분별적 훈련 방식의 하나인 최소 분류 오류 (MCE) 훈련 기법을 도입한다. MCE 훈련 기법을 적용하기 위해 변별력 하락의 가능성을 가지는 '경쟁 요소' 를 결정하는 기법을 제안한다. 병렬결합된 혼합 모델 (PCMM) 기반의 특징 보상에 MCE 훈련 기법을 적용하는 과정을 제안하고 변별력 향상의 영향을 관찰한다. Aurora 2.0 데이터베이스와 실제 자동차 주행 환경에서 수집된 음성 데이터베이스에 대한 성능 평가를 실시한다. 실험 결과는 제안한 기법이 음성 인식 성능 향상에 도움이 되는 것을 입증한다.