• Journal of Applied Reliability
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• v.9 no.2
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• pp.121-130
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• 2009

The power law process model the Rate of occurrence of failures(ROCOF) with monotonic trend during the operating time. However, the power law process is inappropriate when a non-monotonic trend in the failure data is observed. In this paper we deals with the reliability modeling of the failure process of large and complex repairable system whose rate of occurrence of failures shows the non-monotonic trend. We suggest a sectional model and a change-point test based on the Schwarz information criterion(SIC) to describe the non-monotonic trend. Maximum likelihood is also suggested to estimate parameters of sectional model. The suggested methods are applied to field data from an repairable system.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.1
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• pp.90-102
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• 2008

Hydrogen storage is widely recognized as a critical enabling technology for the successful commercialization. There are a few different approaches for hydrogen storage technology. In this paper, characteristics of hydrogen storage technologies were analyzed from the literature survey. Also, The technology trend of hydrogen production was scrutinized based on patent analysis. In patent analysis the search range was limited to the open patents issued from 1996 to 2006. The technology trend of hydrogen storage was assessed by classifying each patent based on the publishing year, country, and the type of storage technology.

• Culinary science and hospitality research
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• v.14 no.3
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• pp.45-57
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• 2008

The purpose of this study is to initiate a systematic approach to maximize profits through continuous development of menu and build a strong image of Western restaurants located inside hotels by identifying their guests' knowledge and concern and menu selection behavior in well being trend. Findings from the analysis are as follows. First, among the Western menu selection behavior, organic grain and seafood, seasonal event menu, less spicy and more natural cooking methods are favored as the most important consideration. Second, customers' knowledge and concern in well being trend and menu selection behavior were found to be statistically significant. Third, customers' awareness in health and obesity were found to be statistically significant to the concern in well being trend. Fourth, demographical characteristics of customers such as gender, marital status, age, income level and education were tested for their relationships with knowledge and concern in well being trend.

• Journal of the Korean Home Economics Association
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• v.41 no.11
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• pp.61-72
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• 2003

The purpose of this study is try to suggest the practical trend of Home Economics Education by analyzing the trends of subject matter education in it. To do this, this study analyzed 115 articles published on The Journal of Korea Home Economics Education Association and The Journal of Korean Home Economics Association. Through this analyzing them, it is found out that teaching-teaming method and teaching materials are trend to be mainly concerned. But recently evaluation study and teacher education study in Home Economics Education have been increased. As a result, Home Economics Education needs to develop the speciality of Home Economics Education as a subject matter education.

• International Journal of Costume and Fashion
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• v.10 no.1
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• pp.29-45
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• 2010

In order to provide more systematic approach to analyze fabric trends and to develop fabrics accordingly, ecology fabric trend from 1986 to 2005 was analyzed related with fabric trend themes and fabric attributes. The result shows that in the 1980s, natural theme appeared, followed by primitive theme and imitated natural theme until the mid 1990s. From the late 1990s to the early 2000s, new natural theme appeared, followed by eco-friendly theme, and then recycling theme. In the natural theme, 'clean' was the most important fabric attribute and 'textured' and 'worn' were important fabric attributes in the primitive theme. In the imitated natural theme, 'wet' fabric attribute was preferred. In the new natural theme, 'lightweight' were preferred. The results of this study empirically demonstrated that abstract and ambiguous trend terms can be interpreted with a physical, substantial, and feasible attributes that fabric practitioners can easily understand.

• Journal of Korean Medicine Rehabilitation
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• v.26 no.3
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• pp.59-65
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• 2016

Objectives The purpose of this review is to analyze domestic research trend of the ossification of posterior longitudinal ligament in Korean medicine. Methods We searched articles in Korean databases such as OASIS, RISS, NDSL and sorted the articles by journals, published year, institutions and research type. Results 9 suitable theses were reviewed. They were published between 2002 till 2011. Most of the theses were published in The Acupuncture, the journal of Korean Acupuncture & Moxibustion Medicine Society. There were 6 case reports, 2 case series and single disease review. Conclusions There were only 9 studies about the ossification of posterior longitudinal ligament in Korean medicine and most of them were case reports. To reinforce the evidence of effectiveness of Korean medicine, additional studies are required and well designed studies such as randomized controlled trials need to be carried out.

• The Journal of Industrial Distribution & Business
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• v.9 no.10
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• pp.83-89
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• 2018

Purpose - The purpose of this study examines when the optimism impact on financial asset price forecasting and the boundary condition of optimism in the financial asset price forecasting. People generally tend to optimistically forecast their future. Optimism is a nature of human beings and optimistic forecasting observed in daily life. But is it always observed in financial asset price forecasting? In this study, two factors were focused on considering whether the optimism that people have applied to predicting future performance of financial investment products (e.g., mutual fund). First, this study examined whether the degree of optimism varied depending on the direction of the prior price trend. Second, this study examined whether the degree of optimism varied according to the forecast period by dividing the future forecasted by people into three time horizon based on forecast period. Research design, data, and methodology - 2 (prior price trend: rising-up trend vs falling-down trend) × 3 (forecast time horizon: short term vs medium term vs long term) experimental design was used. Prior price trend was used between subject and forecast time horizon was used within subject design. 169 undergraduate students participated in the experiment. χ² analysis was used. In this study, prior price trend divided into two types: rising-up trend versus falling-down trend. Forecast time horizon divided into three types: short term (after one month), medium term (after one year), and long term (after five years). Results - Optimistic price forecasting and boundary condition was found. Participants who were exposed to falling-down trend did not make optimistic predictions in the short term, but over time they tended to be more optimistic about the future in the medium term and long term. However, participants who were exposed to rising-up trend were over-optimistic in the short term, but over time, less optimistic in the medium and long term. Optimistic price forecasting was found when participants forecasted in the long term. Exposure to prior price trends (rising-up trend vs falling-down trend) was a boundary condition of optimistic price forecasting. Conclusions - The results indicated that individuals were more likely to be impacted by prior price tends in the short term time horizon, while being optimistic in the long term time horizon.

• Membrane and Water Treatment
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• v.10 no.5
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• pp.339-352
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• 2019

Long term water quality change was analyzed to evaluate the effect of the Total Maximum Daily Load (TMDL) policy. A trend analysis was performed for biochemical oxygen demand (BOD) and total phosphorus (TP) concentrations data monitored at the outlets of the total 41 TMDL unit watersheds of the Nakdong River in the Republic of Korea. Because water quality data do not usually follow a normal distribution, a nonparametric statistical trend analysis method was used. The monthly mean values of BOD and TP for the period between 2004 and 2015 were analyzed by the seasonal Mann-Kendall test and the locally weighted scatterplot smoother (LOWESS). The TMDL policy effect on the water quality change of each unit watershed was analyzed together with the results of the trend analysis. From the seasonal Mann-Kendall test results, it was found that for BOD, 7.8 % of the 41 points showed downward trends, 26.8 % and the rest 65.9% showed upward and no trends. For TP, 51.2% showed no trends and the rest 48.8% showed downward trends. From the LOWESS analysis results, TP began to decrease in most of the unit watersheds from mid-2010s when intensive chemical treatment processes were introduced to existing wastewater treatment plants. Overall, for BOD, relatively more points were improved in the main stream compared to the points of the tributaries although overall trends were mostly no trend or upward. For TP, about half of the points were improved and the rest showed no trends.

• The Journal of Natural Sciences
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• v.17 no.1
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• pp.79-87
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• 2006

Now thus season trend, we can see the multi and digital trend. Specially it was very sensational in fur trend. Many designer showed very shocking and mixed design, silhouette is bulky and fusion short. The background are rise up of kidult, naturalism, techno casual sense, new avangarde. Now, fur is not the classic item anymore. It is necessary to change funny and trendy casual item.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.2
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• pp.65-73
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• 2013

In the simulation output analysis, bootstrap method is an applicable resampling technique to insufficient data which are not significant statistically. The moving block bootstrap, the stationary bootstrap, and the threshold bootstrap are typical bootstrap methods to be used for autocorrelated time series data. They are nonparametric methods for stationary time series data, which correctly describe the original data. In the simulation output analysis, however, we may not use them because of the non-stationarity in the data set caused by the trend such as increasing or decreasing. In these cases, we can get rid of the trend by differencing the data, which guarantees the stationarity. We can get the bootstrapped data from the differenced stationary data. Taking a reverse transform to the bootstrapped data, finally, we get the pseudo-samples for the original data. In this paper, we introduce the applicability of bootstrap methods to the time series data having trend, and then verify it through the statistical analyses.