• Journal of the Korean earth science society
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• v.40 no.5
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• pp.476-486
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• 2019

This study examines the controlling role of synoptic disturbances on $PM_{10}$ spring variability in the Korean Peninsula by using empirical orthogonal function (EOF) and back trajectory analyses. Three leading EOF modes are identified, and a lead-lag analysis suggests that $PM_{10}$ variabilities be closely related to the synoptic weather systems. The first EOF shows the spatially homogeneous distribution of $PM_{10}$, which is influenced by travelling anticyclonic disturbance with negative precipitation and descending motion. The second and third modes exhibit the dipole structures of $PM_{10}$, being associated with propagating cyclones. Furthermore, the back-trajectory analysis suggests that the transport of pollutants by anomalous winds associated with synoptic disturbances also contribute to the altered $PM_{10}$ concentration. Hence, a substantial synoptic control should be considered in order to fully understand the $PM_{10}$ spatiotemporal variability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.435-436
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• 2009

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.62-65
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• 2002

A dieless forming system which consists of hydraulic punch elements and elastomer/fluid pads, was developed for sheet metal forming. 2-D curved surface forming was carried out using open-loop, closed-loop, and repeated forming method. Closed-loop exhibited higher decision than open-loop forming. Repeated forming also showed reduced spring back and possibility of high precision.

• Journal of the Korea Furniture Society
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• v.12 no.2
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• pp.11-18
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• 2001

Steaming has been used for bending wood for a long time, but the steam-bent wood is subject to spring-back and a relatively large radius of curvature. Liquid ammonia is known as an excellent wood plasticizer swelling both crystal and amorphous cellulose. Liquid ammonia technique for wood plasticization was developed and applied for bending alder and padauk pieces, which were used as parts of wooden furniture. The study confirmed that liquid ammonia bent wood can be used for various wood working design.

• The Research Journal of the Costume Culture
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• v.12 no.3
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• pp.392-406
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• 2004

The purpose of this study is to recognize of the size conditions of ready to wear skirts and analyze the patterns of them so that some educational patterns can be complemented. For this purpose, the investigation of the size conditions was focused on the body sizes and products sizes of the care labels. The patterns of them produced through CAD have been classified into 24 items for the effective and practical analysis. Thus, 9 brands were selected and the basic skirts marketed in 2002 spring were analyzed. The results were as follows. 1. Designs of the backs of the basic skirts produced by 9 brands have the similar designs with two darts. Regarding the designs of the front, 6 brands of them have the designs with no darts, 3 of them have the one with two darts. Designs of waists are composed of low waists and round belts. 2. Regarding the waist circumference as the basic composing elements of skirts, 55.6% of the patterns have the composition of the styles with larger front than the back but 33.3% of them have the same front as back. As to the hips, 77.8% of them have the composition of the patterns with larger back than the front. As for the comparison of waist lines, 55.6% of them have lower front lines than the back lines. 3. Regarding darts placement, it was moved to the side lines from the middle of 1/2 of waist lines, dart intake was 1.8-2.4㎝, the length of the front darts was 7.8-9.5㎝, and the length of the back darts 8.4-11.1㎝ 4. The results of wearing-tests by the sensory evaluation, it showed that almost all the items of the results were satisfactory.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.9
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• pp.853-860
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• 2012

This paper identifies a cause of pick up noise in a laser printer and a relationship between pick up noise and major components related to pick up noise. A pick up sound is affected by many components such as spring force, spring constant, and friction coefficient. Objective evaluation for the pick up sound is difficult because of back ground sound such as operating sound. Especially, a sound between a friction pad and a paper in the process of printing has become an essential issue in an aspect of quality evaluation. However the existing criteria for determining the above sound have solely relied on human's subjective judgments; which highlights the requirement to objectify these criteria. In this paper, the standard of existing pick up noise is established by finding the tonality, which is a psychoacoustic parameter, of noticeable limit sound level. Based on the findings of the method, the study has found factors which cause pick up noise and suggests the substitution of following components of printers such as spring constants, spring force, and the quality of friction pads. As a result, it is confirmed that the proposed pick up noise index has usefulness to classify whether existence of pick up noise with an objective evaluation and not to occur the noise based on design optimized combination of laser printer components.

• Atmosphere
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• v.17 no.4
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• pp.407-420
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• 2007

Optical characteristics of aerosols in Seoul are investigated from the measurements of sky radiance by Skyradiometer at Yonsei University from December 2005 to November 2006. Aerosol optical depth (AOD) shows a maximum in June due to weak ventilation and particle growth by aging process and hygroscopic effect. Single scattering albedo (SSA) and Angstrom Exponent (AE) show the lowest value in spring due to the Asian dust. It is clear that coarse mode is dominant in spring and fine mode is dominant in summer from the volume size distribution measured in this study. The explanations on the changes of aerosol loadings are provided through the correlation between AOD and AE, while the pattern of wavelength dependency related to particle size is shown through the correlation between SSA and AE. Backward trajectory analysis by HYSPLIT provides information about origin of aerosol, which allows us to classify the case according to the source region and the path distance. Although the direction of backward trajectory traces back mostly to west, coarse mode particle is dominant in the case of long pathway and fine mode particle is dominant in the case of short pathway. This discrepancy is caused by the regional difference of emitted particles.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.1049-1054
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• 2003

A group of Hanwoo (Korean cattle) steers (n=14,386) was sampled from a commercial abattoir located in Seoul over one year period (spring, summer, autumn and winter) and their carcass traits were collected. Carcass traits assessed by an official meat grader comprised degree of marbling, meat color, fat color, texture and maturity for quality grade, and back fat thickness, ribeye area and carcass weight for yield grade. A heavier carcass with a higher marbling score, more red meat color and white fat color received better quality grade (p<0.05). Regression analysis showed that the marbling score was the strongest attribute (partial $R^2=0.88$) for quality grade. Lighter carcasses with a thinner back fat and larger ribeye area received higher yield grade score. The back fat thickness was the most negative determinant of yield grade (Partial $R^2=-0.66$). The slaughter season had a little effect on quality and yield grades. As slaughter weight increased, back fat thickness and ribeye area increased linearly, whereas marbling score reached its asymptotic level at approximately 570 kg. As a consequence, quality grade showed a considerable improvement up to 570 kg, but increases in slaughter weight afterward showed a little benefit on quality grade. There was a clear curvilinear relationship between slaughter weight and yield grade in that the yield grade reached its highest point at approximately 490 kg and decreased afterward. These results suggested that 570kg at the age of 24 months might be the economic slaughter weight for quality grade but 490 kg for yield grade.

• Korean Journal of Agricultural Science
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• v.43 no.4
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• pp.589-594
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• 2016

The objective of the current study was to investigate the effect of odor reducing agents on the levels of pH, total carbon, total nitrogen, and odorous compounds [phenols, indoles, short chain fatty acid (SCFA), branched-chain fatty acid (BCFA), and ammonium nitrogen] of swine manure during the spring season (temperature around $20^{\circ}C$). Odor reducing agents included horseradish powder, mushroom waste powder, and almond hull powder. A manure sample (15 L) was taken from the pit under the pens of a swine feeding operation and incubated with 0.03% horseradish powder, 1% mushroom waste powder, and 1% almond hull powder, respectively, in acryl chambers for 14 days. Addition of almond hull powder showed the lowest pH (p < 0.05) and the highest level of total carbon (p < 0.05) among treatments of odor reducing agents. Although addition of odor reducing agents increased the level of phenols (p < 0.05), addition of almond hull powder decreased the level of indoles (p < 0.05). Levels of SCFA and BCFA were higher in almond hull powder than those in control (p < 0.05). Taken together, the results from our current study showed that odor reducing agents can be used for reducing the odor of swine manure by providing fermentable carbohydrates. At $20^{\circ}C$, however, the function of odor reducing agents might be decreased due to lower microbial activity.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.111-120
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• 2016

Acoustic surveys using a scientific echosounder and trawl surveys were concurrently carried out in between Geoje and Tongyeong of the South Sea by season. The anchovy schools were identified by trawling in each station and used for frequency response analysis. Frequency responses of anchovy schools by season and species composition ratio were examined using multi-frequencies (18, 38, 70, 120 and 200 kHz). The frequency response r(f), is one of the acoustic characteristics which means the volume back-scattering strength ratio between a reference frequency and other frequencies. In spring, the r(f) of anchovy schools decreased with increased frequency, with the exception of 120kHz. While, in winter, the r(f) continuously decreased inversely proportional to the increase in frequency. Frequency response of anchovy schools presented a distinctive difference between spring and winter, however it did not different in spife of different species composition ratios in schools.