• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.192-193
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• 2015

Construction Cycle Trend Survey, which survey total value of orders and realized amounts monthly, is a valuable statistics that used to quick grasp or forecast the trend of domestic construction business. In recent periodical survey quality diagnoses, few professional users named a problem that Construction Cycle Trend Survey could not get together with the current state of the construction industry. This study examined weather Construction Cycle Trend Survey reflects the economic sentiment of construction business or not. Paired t test was performed between Construction Cycle Trend Survey and Construction Business Survey Index (CBSI), and significant differences were verified.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.10a
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• pp.99-99
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• 1994

• International Area Studies Review
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• v.21 no.4
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• pp.159-172
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• 2017

In a typical trend-cycle decomposition of GDP, the trend component is usually assumed to follow a random walk process. This paper considers an ARIMA trend and assesses the validity of the ARIMA trend model. I construct univariate and bivariate unobserved-components(UC) models, allowing the ARIMA trend. Estimation results using U.S. data are favorable to the ARIMA trend models. I, also, compare the forecasting performance of the UC models. Dynamic pseudo-out-of-sample forecasting exercises are implemented with recursive estimations. I find that the bivariate model outperforms the univariate model, the smoothed estimates of trend and cycle components deliver smaller forecasting errors compared to the filtered estimates, and, most importantly, allowing for the ARIMA trend can lead to statistically significant gains in forecast accuracy, providing support for the ARIMA trend model. It is worthy of notice that trend shocks play the main source of the output fluctuation if the ARIMA trend is allowed in the UC model.

• Journal of the Korean Society of Costume
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• v.58 no.9
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• pp.18-28
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• 2008

The purpose of this study is to examine the Characteristics of Fashion Trends($1996{\sim}2005$) of Korea by the trend elements - style, fabric and color. The results of this study are as followed. During 10years, 'modern(18%)', 'elegant(11%)' and 'romantic(10%)' styles were shown in order, and colors of YR(17%), Y(14%), R(13%) and PB(11%) were shown in order. Considering tones, m(16%), d(12%), gy(11%) and s(10%) tones were in the order of frequency. In the fabric trend 'elegant(19%)', 'modern(14%)' and 'natural(14%)' images showed the high frequency. Since 2000's, style trends and fabric trends were subdivided, and the contrary images coexisted. The trend images of 'natural', 'retro', 'manish' and 'fun' were mainly used in fabric trend, and 'romantic' and 'classic' images were frequently used in style trend. The changes of trend images in style and fabric have been similar until the early 2000's but the cycle of trend of style became shorter than fabric trend. Therefore the cycle of fabric trend should be changed to be a short term and subdivided in company with style trend.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.6
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• pp.786-798
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• 2013

This study establishes a fashion theory frame to forecast future fashion cycles of pants through analyzing past fashion cycles of pants through a diachronic method. Pants pictures from 1967-2012, post-industrialized period of Korea were analyzed. Representative pant styles, fashion cycles of pants and the relation of pant styles, length and width were identified. The total of 1006 pictures in fashion magazine published over 46 years were selected and analyzed using PASW 18.0 (statistical program). The results are as follows. For 46 years, representative pant styles were skinny, regular and bell-bottom. The first cycle period was from 1969 to 1992 and lasted 24 years. The second cycle period was from 1993 to 2003 and lasted 11 years. The third cycle is ongoing as of 2004. Fashion cycles have shown a general trend to be shortened. The relation between pant styles, length and width revealed related results; in addition, pant length and width changed significantly in a similar orientation. Fashion marketers can develop successful products using fashion cycle theory from these results.

• Journal of Society of Preventive Korean Medicine
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• v.14 no.2
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• pp.105-120
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• 2010

Objectives : This study aims to evaluate the effects of expiration-to-inspiration time ratio (E/I-ratio) on heart rate, which represents cardiac autonomic function, and cold-heat in the healthy people. Methods : 49 healthy young volunteers(male : female = 32 : 17) were recruited in the study. The participants completed the questionnaire for yin-yang pattern identification and then we measured the chest plethysmogram for respiration signal and the electrocardiogram for NN intervals during different E/I-ratio from 1 to 2. We compared heart rate variability including RMS-SD, VLF, LF and HF, and the trend-cycle factors decomposed from NN interval data by time series analysis among the respective E/I-ratio. We also confirmed the difference on the trend-cycle factors according to the score of the questionnaire for cold and heat pattern identification. Results : There were differences on the trend-cycle factors from NN interval data, but no significant difference on heart rate variability, among the respective E/I-ratio. We also found significant relationship between the trend-cycle factors and the heat pattern identification scores. Conclusions : The results indicate that cardiac autonomic function can be modulated by the E/I-ratio and the modulation will be slower and more tendencious than respiratory sinus arrhythmia.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.4
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• pp.584-597
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• 2014

This study verified the 'Hemline Index' theory by George (1926) and established a new fashion theory frame to forecast future fashion cycles of skirts by analyzing the past fashion cycle of skirts through a diachronic method. Skirt pictures from 1980-2013 (the post-industrialized period of Korea) were analyzed and representative skirt styles, the fashion cycle of skirts and relation between skirt style, length, width and stock index were identified. A total of 1496 pictures in fashion magazine published over 34 years were selected and analyzed using PASW 18.0. The results were: For 34 years, representative skirts styles were mini skirt, midi skirt and long skirt. Fashion trend cycles of skirt length decreased for 10 years and the fashion cycle showed a trend to shorten. Skirt length & stock index related negatively and skirt length & skirt width related positively. All relations revealed significant results. Finally, the 'Hemline Index' theory of George (1926) was verified. Fashion marketers can develop successful and suitable products using a fashion cycle theory based on the results of this study.

• KDI Journal of Economic Policy
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• v.31 no.2
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• pp.47-85
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• 2009

With a relatively simple quantitative method, this study comprehensively analyzes the characteristics related to business cycles represented by macroeconomic variables of Korea since 1970. This empirical analysis deals with roughly following three topics: How to identify cyclical component with respect to trend; with what characteristics and how the economic variables of each sector move with in the phases of business cycle, and; whether there are signs of a structural change in the phases of business cycle. Section 2 discusses how to identify trends and cycle components, the basis assumption for the analysis of business cycle. Like the Korean economy, where a relatively high growth rate has been maintained, it is appropriate to determine its economic recession based on the fall in the growth trend, not in the absolute level of real output. And, it is necessary to apply the concept of growth cycle against a traditional concept of business cycle. Accordingly the setting of growth trend is of preliminary importance in identifying cyclical fluctuations. The analysis of Korea's GDP data since 1970, the decomposition of trends and cycles through the Band-pass filter is found to appropriately identify the actual phases of busyness cycle. Section 3 analyzes what particular relationship various economic variables have with output fluctuations during the phases of economic cycle, using the corss-correlation coefficients and prediction contribution. Section 4 monitors the stability of the phases of Korea's business cycle and quantitatively verifies whether there is a structural break, and then reviews the characteristics of variations in each sector. And, stylized facts observed through these studies are summarized in the conclusion. The macroeconomic stability of Korea, in particular, is found to continue to improve since 1970, except for the financial crisis period. Not only that, it is found that its volatility of economic growth rate as well as inflation have been reduced gradually. Meanwhile, until recently since 2000, the volatility in domestic demand has remained stable, while that in exports and imports has been increased slightly. But, in an over all perspective, Korea's business cycle variation is on the decline due to shorter response period to shocks and the formation of complementary relationship among economic sectors.

• The Research Journal of the Costume Culture
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• v.12 no.3
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• pp.327-338
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• 2004

This study was attempted to check period of a fashion cycle and to suggest its main-stream and sub-stream by analyzing the fashion trends presented in Vogue Korea between 1997 and 2002. A content analysis method was used to analyze 24 volumes. The result showed that the fashion trend of 1997's was a turning point from the simplicity, which was a trend up to 1996's, to the romanticism. The fashion trends of 2002 seemed to be also a turning point from the new-romanticism which was added the hippism to the romanticism continued from 1997, to the sporticism. The result confirmed that the main-stream of fashion theme have been continued for 5 years as a regular cycle system and could be repeated. It also verified that some sub-stream which was affected by social, cultural and political situation led the fashion changes. The results of this study could be expected to reflect not only fashion design, merchandising and marketing strategy but also consumer purchase behavior of the future.

• Journal of the Korean Professional Engineers Association
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• v.34 no.2
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• pp.31-36
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• 2001

The Otto Cycle of conventional gasoline engine has no difference between compression ratio and expension ratio. because of the same length of 4 strokes : Intake, compression, expension, exhaust. On the other hand, miller cycle engine achieves both low-compression ratio and high-compression ratio by shortening the length of compression stroke among 4 strokes. Therefore miller cycle engine is essential for lessening knocking and improving heat efficiency. This paper Is designed to discribe not only principle and the development trend of miller cycle engine but also the control system and the technical characteristics of it.