• Title/Summary/Keyword: stopping times

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Growth of pollen tube between self pollination and interspecific pollination of Lilium Genus (Lilium 속의 자가수분 및 불화합성의 종간의 교잡수분에 미치는 화분관의 생장 행동)

  • EuiSooYoon
    • Korean Journal of Plant Resources
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    • v.3 no.2
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    • pp.123-128
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    • 1990
  • In every reciprocal crosses of self pollination, interspecific pollination through ordinary stigma pollination of L. longiflorum and $L.{\;}{\times}{\;}elegans$, pollen vigorously germinated in stigma, and pollen tube was growing. But, 5 days after pollination, pollen tube stopping their growth in the same style as was observed in the cross of self pollination and interspecific pollination. Intrastylar pollination of $L.{\;}{\times}{\;}elegans$ and L. longiflorum passed stylar cannal through the basal part of styles. But, pollen tube that was growing to the ovule of the ovary was extremely small. In morphogical observation of ovary 10 days after pollination, it was observed, that every reciprocal crosses of L. longiflorum ${\times}$ L. ${\times}$ elegans was fertilized through intrastylar pollination, so that this technique was used to overcome cross incompatibilities.lities.

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Some Properties of Sequential Point Estimation of the Mean

  • Choi, Ki-Heon
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.3
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    • pp.657-663
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    • 2005
  • Under the minimum risk point estimation formulation of Robbins(1959), we consider the sequential point estimation problem for normal population $N({\theta},\;{\theta})$ with unknown parameter ${\theta}$. In the case of completely unknown ${\theta}$, Stein's(1945) two-stage procedure is known to enjoy the consistency property, but it is not even first-order efficient. In the case when ${\theta}>{\theta}_L\;where\;{\theta}_L(>0)$ is known, the revised two-stage procedure is shown to enjoy all the usual second-order properties.

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An Ergonomic Design of Brake and Accelerator Pedal Placement for Korean Driver (자동차 브레이크 페달 배치의 인간공학적 설계)

  • 김유창
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.106-109
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    • 1995
  • Optimum relocation of the brake relative to the accelerator can reduce stopping diatance and may mean the difference between an accident and a near-accident. A driving simulator was used to examine effiency of brake time. Brake time was measured for 30 participants in six conditions. Brake times were shown to improve as a result of moving the brake pedal from its typical heights above the accelerator to positions below the accelerator.

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Analysis of Bicycle Crossing Times at Signalized Intersections for Providing Safer Right of Bicycle Users (자전거 이용자 행태 반영을 위한 신호교차로에서의 자전거 횡단시간 연구)

  • Son, Young-Tae;Lee, JIn-Kak;Lee, Sang-Hwa;Kim, Hong-Sang
    • International Journal of Highway Engineering
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    • v.9 no.3
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    • pp.83-89
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    • 2007
  • When allocating traffic signal at the signalized intersection, minimum green time and clearance time for bicyclists should be significantly considered in order to enhance safety aspects to bicyclists when crossing intersections, especially where intersections with exclusive bicycle paths that are physically separated from pedestrians. In this study, field measurements related to bicycle crossing time, including minimum peen time and clearance time, were collected and analyzed according to bicycles crossing types at the signalized intersections where high rate of bicyclists exists. Three types of bicycle crossing are defined as follows 1) stopping: completely stop before crossing (at least one foot on found) 2) riding: crossing with riding bicycle 3) pulling: crossing without riding bicycles. Minimum green time based on pedestrian speeds should be used as crossing time in this case. For bicyclists, speed of bicycle that is applicable to estimate the minimum green time is in the 1.36m/sec($15^{th}$ percentile) to 1.60m/sec($25^{th}$ percentile) range in case of its stopping. Also it is in the 0.75($15^{th}$ percentile) to 0.87($25^{th}$ percentile) range for pulling at crosswalk. In addition, speed of bicycle to consider for calculating the clearance time is in the 2.51m/sec($15^{th}$ percentile) to 2.79m/sec($25^{th}$ percentile). These values also resulted from $15^{th}$ percentile or $25^{th}$ percentile speeds of riding. The results of this study are expected to be supported in traffic signal allocation process, reflecting bicyclists' characteristics.

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The Effects of Auditory Biofeedback Training and Kicking Training on Walking Speeds in Patients with Hemiplegia

  • Jun, Hyun Ju;Lee, Jin Su;Kim, Ki Jong
    • Journal of International Academy of Physical Therapy Research
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    • v.5 no.1
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    • pp.675-682
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    • 2014
  • The objective of this study was to examine the effects of auditory biofeedback training and kicking training on walking times in patients with hemiplegia to determine if the effects of such training would be maintained even after stopping the intervention. Thirty hemiplegia patients were selected and randomly assigned to a control group of 10 patients to receive general exercise treatment; an auditory biofeedback training group of 10 patients to receive auditory biofeedback training, along with general exercise; and a kicking training group to receive kicking training, along with general exercise. All the patients received their respective training 12 times in total, three times per week for four weeks. In addition, all those in the control and experimental groups received the same general exercise treatment 12 times in total, three times per week for four weeks, and underwent follow-up tests thereafter. The patients' 10m walking times were measured using a stopwatch. The significance was analyzed using repeated-ANOVAs. In cases where there were interactions between measuring times and groups, in each group were examined using repeated-ANOVAs. In cases where there were differences, post-hoc tests were conducted using repeated of contrast test. The 10m walking times of the control and experimental groups were significant differences in 10m walking times were shown between measurement times(p<.05), and significant differences in the interactions between measuring times and groups were shown between the groups(p <.05). However, no significant differences in 10m walking times were shown between the groups(p>.05). The auditory biofeedback training group showed significant decreases in walking times four weeks after the beginning of the intervention(p<.05) and significant increases eight weeks after the beginning of the intervention(p<.05). The kicking training group showed significant decreases in walking time four weeks after the beginning of the intervention(p<.05) and maintained the walking times without showing any significant differences eight weeks after the beginning of the intervention(p>.05). The walking speeds of only the kicking training group were maintained until eight weeks after the beginning of the intervention.

A Review on Smoking Patterns among Public Officiers (일부 공무원들의 흡연유형에 관한 고찰)

  • Hyun Kyoung Soon
    • Journal of Korean Public Health Nursing
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    • v.9 no.2
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    • pp.33-42
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    • 1995
  • The purpose of this study is to identify the smoking patterns and their relevant factors of the public officials who are placed to guide people's way of thinking as conservative middle-income group and thereupon, provide for basic data which can be used to reduce the diseases and death rate caused by smoking in terms of preventive medicine. For this purpose, 170 public officials working for the government agencies located in seoul were surveyed for Jan. 10-Jan. 20, 1995. The results of survey can be analyzed/summarized as follows; 1. In terms of daily smoking frequencies, 50 officials $(29.4\%)$ are driven by stress to smoke. Among these offcials, 250nes $(50.0\%)$ smoke 20-30 times a day. Meanwhile, 22 officials $(12.9\%)$ answered that they smoke for pleasure and comfort, and among them 6 officials $(21.4\%)$ smoke 20-30 times a day. 26 officials $(15.3\%)$ are found to be nicotine­addicted physically or psychologically, and to 10 of them $(35.7\%)$ smoke 20-30 times a day. On the other hand, 10 officials $(5.9\%)$ have habit of smoking and 4 of them $(40.0\%)$ smoke 20-30 times a day. 2. Out of 50 officials $(24.9\%)$ who began smoking on impulse, 44 actually stopped smoking, and the rest 6 officials did not even implement their plan. In view of successful cigarette-stopping, only 8 officials $(15.4\%)$ out of 44 impulse-driven smokers succeeded in stopping cigarettes, while the rest 36 failed all. Meanwhile, out of those 84 officials $(64.6\%)$. Who smoked for reduced stress, 28 ones succeeded, while the rest 56 ones failed. Out of 20 officials who were nicotine-addicted but attempted to stop smoking, only 2 smokers succeeded and the rest 18 were all failures. 3. Factors involving smoking and Their patterns 1) By age group (30's, 40's and 50's), the smoking patterns can be grouped into stress-removing, nocotine-addictive and habitual ones, respectively. 2) By acadeic background, our officials smoke on impulse or due to nocotine addition. 3) The length of career is co-related with nicotine addition. 4) The ownership of house is related with smoking for comfort or less stress. 5) The number of children is related with impulse-driven smoking or smoking for comfort.

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Genome-Wide Association Study Identifies Candidate Loci Associated with Platelet Count in Koreans

  • Oh, Ji Hee;Kim, Yun Kyoung;Moon, Sanghoon;Kim, Young Jin;Kim, Bong-Jo
    • Genomics & Informatics
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    • v.12 no.4
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    • pp.225-230
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    • 2014
  • Platelets are derived from the fragments that are formed from the cytoplasm of bone marrow megakaryocytes-small irregularly shaped anuclear cells. Platelets respond to vascular damage, contracts blood vessels, and attaches to the damaged region, thereby stopping bleeding, together with the action of blood coagulation factors. Platelet activation is known to affect genes associated with vascular risk factors, as well as with arteriosclerosis and myocardial infarction. Here, we performed a genome-wide association study with 352,228 single-nucleotide polymorphisms typed in 8,842 subjects of the Korea Association Resource (KARE) project and replicated the results in 7,861 subjects from an independent population. We identified genetic associations between platelet count and common variants nearby chromosome 4p16.1 ($p=1.46{\times}10^{10}$, in the KIAA0232 gene), 6p21 ($p=1.36{\times}10^{-7}$, in the BAK1 gene), and 12q24.12 ($p=1.11{\times}10^{-15}$, in the SH2B3 gene). Our results illustrate the value of large-scale discovery and a focus for several novel research avenues.

Effect of Number of Shutdown on the Decrease of Performance in PEM Water Electrolysis (PEM 수전해에서 정지횟수가 성능 감소에 미치는 영향)

  • Cheunho Chu;Jongwon Yang;Ilchai Na;Yoonjin Park
    • Korean Chemical Engineering Research
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    • v.61 no.2
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    • pp.202-207
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    • 2023
  • In the case of driving water electrolysis by receiving surplus electricity from solar and wind power generation, operation and stopping must be repeated according to weather fluctuations. When the PEMWE(Polymer Electrolyte Membrane Water Electrolysis) is driven and stopped, the PEM fuel cell is in the same state as the PEM fuel cell due to the residual hydrogen and oxygen, and the high potential of the water electrolysis formed during operation is highly likely to cause degradation of the electrode and membrane even during stopping. In this study, in order to check how much degradation of the electrode and membrane progresses during the repeated driving/shutdown process of PEM water electrolysis, the performance decrease was measured by changing the number of driving/shutdown for 144 hours. Changes in electrode catalyst active area, hydrogen permeability and fluorine emision rate of membranes were analyzed to measure changes in the properties of electrodes and polymer membranes. Overall, the PEMWE performance decreased as the number of stops increased. When stopped 5 times in 144 hours, the IrOx catalyst activity decreased by more than 30%, and the hydrogen permeability increased by 80%, confirming that both the electrode and the membrane were deteriorated.

Exposures of Ultrafine Particles for Passengers of Elephant Vehicle in the Seoul Grand Park (서울대공원 코끼리 열차 특성에 따른 탑승자의 초극미세입자(Ultrafine Particles) 노출)

  • Joo, Song-Yi;Hwang, Ji-Hee;Ham, Seung-Hon;Lee, Ki-Young
    • Journal of Environmental Health Sciences
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    • v.38 no.5
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    • pp.393-397
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    • 2012
  • Objectives: The objectives of this study were to measure passengers' exposure to ultrafine particles (UFP) and to determine effects of fuel, operating condition and position of seat. Method: UFP exposures in front and back seats of the Elephant vehicle in Seoul Grand Park were simultaneously measured by a condensation particle counter (P-Trak model 8525, TSI). The measurements were conducted 7 times with diesel-powered vehicle and 3 times with electricity vehicle in one day. The vehicle stopped at 3 locations along with 2.2 km of driving route. Results: UFP concentration in diesel-powered vehicle was significantly higher than electricity vehicle. At front seat of diesel-powered vehicle, average UFP exposure during stopping was significantly higher than during moving. When diesel-powered vehicle moved, UFP exposure in back seat was significantly higher than in front seat. Conclusions: Passengers in the diesel-powered Elephant vehicle could be exposed to high level of UFP. The UFP exposure was associated with operation condition and position of seat.

Optimal Periodic Replacement Policy Under Discrete Time Frame (이산 시간을 고려한 시스템의 교체와 수리 비용 최적화 연구)

  • Lee, Jinpyo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.1
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    • pp.61-69
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    • 2020
  • Systems such as database and socal network systems have been broadly used, and their unexpected failure, with great losses and sometimes a social confusion, has received attention in recent years. Therefore, it is an important issue to find optimal maintenance plans for such kind of systems from the points of system reliability and maintaining cost. However, it is difficult to maintain a system during its working cycle, since stopping works might incur users some troubles. From the above viewpoint, this paper discusses minimal repair maintenance policy with periodic replacement, while considering the random working cycles. The random working cycle and periodic replacement policies with minimal repair has been discussed in traditional literatures by usually analyzing cases for the nonstopping works. However, maintenance can be more conveniently done at discrete time and even during the working cycle in real applications. So, we propose that periodic replacement is planned at discrete times while considering the random working cycle, and moreover provide a model in which system, with a minimal repair at failures between replacements, is replaced at the minimum of discrete times KT and random cycles Y. The average cost rate model is used to determine the optimal number of periodic replacement.