• Journal of Preventive Medicine and Public Health
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• v.36 no.1
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• pp.71-76
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• 2003

Objectives : New organizational work systems, and their impact on the mental health of employees, are considered to beone of the most important topics in the area of industrial health. This study was conducted to compare job characteristics (job demand and decision latitude) levels, and psychosocial distress of workers in acompany introducing to new organizational work systems, to those of workers managed by traditional work systems. Methods ; A study sample of 627 shipbuilding workers (446the new work organizational system and 181 the traditional system) were recruited for this study. A structured-questionnaire was used to assess general characteristics, job characteristics(work demand, decision latitude), and psychosocial distress. Results : The decision latitude was not significantly higher in the new work system compared to the traditional system. However, the job demand was significantly higher in the new work system than in the traditional system. The psychosocial distress was higher within the new work system than the traditional system, but no significant relationships were found. The proportion of increased strain was significantly greater with the new system than the traditional system. Conclusion : These results suggest that increases in the decision latitude did not sufficiently compensate for higher job strain or increased work intensity. If the increase in the decision latitude was temporary, with the typical job demand remaining high, such work can be still be considered to have a job strain Futureresearch should consider psychosocial distress and fatigue as importantproblems caused by new work organizational systems, and should be performed to assess their impact through out industry.

• Journal of Astronomy and Space Sciences
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• v.27 no.3
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• pp.205-212
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• 2010

To better understand the physical processes that maintain the high-latitude lower thermospheric dynamics, we have identified relative contributions of the momentum forcing and the heating to the high-latitude lower thermospheric winds depending on the interplanetary magnetic field (IMF) and altitude. For this study, we performed a term analysis of the potential vorticity equation for the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions, with the aid of the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM). Difference potential vorticity forcing and heating terms, obtained by subtracting values with zero IMF from those with non-zero IMF, are influenced by the IMF conditions. The difference forcing is more significant for strong IMF $B_y$ condition than for strong IMF $B_z$ condition. For negative or positive $B_y$ conditions, the difference forcings in the polar cap are larger by a factor of about 2 than those in the auroral region. The difference heating is the most significant for negative IMF $B_z$ condition, and the difference heatings in the auroral region are larger by a factor of about 1.5 than those in the polar cap region. The magnitudes of the difference forcing and heating decrease rapidly with descending altitudes. It is confirmed that the contribution of the forcing to the high-latitude lower thermospheric dynamics is stronger than the contribution of the heating to it. Especially, it is obvious that the contribution of the forcing to the dynamics is much larger in the polar cap region than in the auroral region and at higher altitude than at lower altitude. It is evident that when $B_z$ is negative condition the contribution of the forcing is the lowest and the contribution of the heating is the highest among the different IMF conditions.

• Journal of Astronomy and Space Sciences
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• v.34 no.2
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• pp.161-170
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• 2017

In this study, the characteristics of a horizontal sundial from the Joseon Dynasty were investigated. Korea's Treasure No. 840 (T840) is a Western-style horizontal sundial where hour-lines and solar-term-lines are engraved. The inscription of this sundial indicates that the latitude (altitude of the north celestial pole) is $37^{\circ}$ 39', but the gnomon is lost. In the present study, the latitude of the sundial and the length of the gnomon were estimated based only on the hour-lines and solar-term-lines of the horizontal sundial. When statistically calculated from the convergent point obtained by extending the hour-lines, the latitude of this sundial was $37^{\circ}$ $15^{\prime}{\pm}26^{\prime}$, which showed a 24' difference from the record of the inscription. When it was also assumed that a convergent point is changeable, the estimation of the sundial's latitude was found to be sensitive to the variation of this point. This study found that T840 used a vertical gnomon, that is, perpendicular to the horizontal plane, rather than an inclined triangular gnomon, and a horn-shaped mark like a vertical gnomon is cut on its surface. The length of the gnomon engraved on the artifact was 43.1 mm, and in the present study was statistically calculated as $43.7{\pm}0.7mm$. In addition, the position of the gnomon according to the original inscription and our calculation showed an error of 0.3 mm.

• Journal of The Korean Astronomical Society
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• v.42 no.3
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• pp.55-60
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• 2009

The properties of SOHO/LASCO CMEs are subjected to projection effects. Their dependence on the source position is important to be studied. Our main aim is to study the dependence of CME properties on helio-longitude and latitude using the CMEs associated with type IIs observed by Wind/WAVES spacecraft (Deca-hecta metric type IIs - DH type IIs). These CMEs were identified as a separate population of geo-effective CMEs. We considered the CMEs associated with the Wind/WAVE type IIs observed during the period January 1997 - December 2005. The source locations of these CMEs were identified using their associated GOES X-ray flares and listed online. Using their locations and the cataloged properties of CMEs, we carried out a study on the dependence of CME properties on source location. We studied the above for three groups of CMEs: (i) all CMEs, (ii) halo and non-halo CMEs, and (iii) limb and non-limb CMEs. Major results from this study can be summarized as follows. (i) There is a clear dependence of speed on both the longitude and latitude; while there is an increasing trend with respect to longitude, it is opposite in the case of latitude. Our investigations show that the longitudinal dependence is caused by the projection effect and the latitudinal effect by the solar cycle effect. (ii) In the case of width, the disc centered events are observed with more width than those occurred at higher longitudes, and this result seems to be the same for latitude. (iii) The dependency of speed is confirmed on the angular distance between the sun-center and source location determined using both the longitude and latitude. (iv) There is no dependency found in the case of acceleration. (v) Among all the three groups of CMEs, the speeds of halo CMEs show more dependency on longitude. The speed of non-halo and non-limb CMEs show more dependency on latitude. The above results may be taken into account in correcting the projection effects of geo-effective CMEs.

• Journal of The Korean Astronomical Society
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• v.46 no.2
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• pp.75-91
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• 2013

We estimate the power spectra of the cosmic microwave background radiation (CMB) temperature anisotropy in localized regions of the sky using the Wilkinson Microwave Anisotropy Probe (WMAP) 7-year data. We find that the north and south hat regions at high Galactic latitude ($|b|{\geq}30^{\circ}C$) show an anomaly in the power spectrum amplitude around the third peak, which is statistically significant up to 3. We try to explain the cause of the observed anomaly by analyzing the low Galactic latitude ($|b|$ < $30^{\circ}C$) regions where the galaxy contamination is expected to be stronger, and the regions weakly or strongly dominated byWMAP instrument noise. We also consider the possible effect of unresolved radio point sources. We find another but less statistically significant anomaly in the low Galactic latitude north and south regions whose behavior is opposite to the one at high latitude. Our analysis shows that the observed north-south anomaly at high latitude becomes weaker on regions with high number of observations (weak instrument noise), suggesting that the anomaly is significant at sky regions that are dominated by the WMAP instrument noise. We have checked that the observed north-south anomaly has weak dependences on the bin-width used in the power spectrum estimation, and on the Galactic latitude cut. We also discuss the possibility that the detected anomaly may hinge on the particular choice of the multipole bin around the third peak. We anticipate that the issue of whether or not the anomaly is intrinsic one or due to WMAP instrument noise will be resolved by the forthcoming Planck data.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.299-308
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• 2006

This study was conducted to investigate differences in energy content of Quercus mongolica stands in the Republic of Korea with respect to latitude and altitude. Study sites were located in Mt. Joongwang, Pyeongchang-gun, Gangwon-do (altitude 1,300 m, 1,000 m, 800 m), Mt. Taehwa, Gwangju-gun, Gyeonggi-do (altitude 350 m), Mt. Wolak, Jecheon-si, Chungcheongbuk-do (altitude 300 m), Mt. Baekwoon, Gwangyang-gun, Jeollanam-do (altitude 800 m), and Mt. Halla, Jeju-do (altitude 1,000 m) by northern and southern aspect. Total energy content and annual energy fixation of Q. mongolica stands were 2,916-6,550 GJ/ha and 250-440 GJ/ha, respectively during the study period, Lower latitude (NE) stands of Q. mongolica showed more energy contents and annual energy fixation than higher latitude stands. Energy content and annual energy fixation of Q. mongolica stands were increased in low altitude. Energy content of Q. mongolica stands were higher in northern aspect than southern aspect. However, there were no significant differences in annual energy fixation between the aspects. Annual energy fixation of Q. mongolica stands was highly correlated with warm index and followed by descending orders: altitude, stand age, aspect, annual solar radiation and latitude.

• Journal of Astronomy and Space Sciences
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• v.38 no.2
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• pp.135-143
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• 2021

We report, for the first time, the afternoon (i.e., from noon to sunset time) observations of the northern mid-latitude E-region field-aligned irregularities (FAIs) made by the very high frequency (VHF) coherent backscatter radar operated continuously since 29 December 2009 at Daejeon (36.18°N, 127.14°E, 26.7°N dip latitude) in South Korea. We present the statistical characteristics of the mid-latitude afternoon E-region FAIs based on the continuous radar observations. Echo signal-to-noise ratio (SNR) of the afternoon E-region FAIs is found to be as high as 35 dB, mostly occurring around 100-135 km altitudes. Most spectral widths of the afternoon echoes are close to zero, indicating that the irregularities during the afternoon time are not related to turbulent plasma motions. The occurrence of afternoon E-regional FAI is observed with significant seasonal variation, with a maximum in summer and a minimum in winter. Furthermore, to investigate the afternoon E-region FAIs-Sporadic E (E_s) relationship, the FAIs have also been compared with E_s parameters based on observations made from an ionosonde located at Icheon (37.14°N, 127.54°E, 27.7°N dip latitude), which is 100 km north of Daejeon. The virtual height of E_s (h'E_s) is mainly in the height range of 105 km to 110 km, which is 5 km to 10 km greater than the bottom of the FAI. There is no relationship between the FAI SNR and the highest frequencies (f_tE_s) (or blanket frequencies (f_bE_s)). SNR of FAIs, however, is found to be related well with (f_tE_s-f_bE_s).

• Journal of Global Scholars of Marketing Science
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• v.13
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• pp.71-88
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• 2004

Although the factors that affect the width of latitude of price acceptance is well documented, the attempt to develop a practice-oriented methodology to calibrate the region of price insensitivity (i.e., a latitude of price acceptance) for a given individual brand has been relatively rare. The researcher aims to try to full this gap by developing a conjoint analysis-based procedure that can be applied to many industries. Furthermore, we examine the difference in the latitude of price acceptance between on- and off-line transaction in stock industry in Korea. The conjoint analysis-based procedure was applied to measure the disaggregate price response curve for individual stock investment both on- and off line transaction channel. The curves from the samples enable us to estimate the individual choice probabilities corresponding to applied price points. Using t-test the differences in mean choice probabilities between the list price and another price point were tested, through which we can get the latitude of price acceptance for a given brand in stock market. These procedures were tested in on- and off-line stock market in South Korea. The results showed that investors on off-line channel have wider latitudes of price acceptance than the investors on on-line transaction system.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.120-128
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• 2010

This experiment was conducted to investigate the variation of crude protein, crude oil, fatty acid, and sugar contents in five Korean domestic black soybean cultivars grown at different latitudinal locations, a high latitude, Suwon ($37^{\circ}$16'N) and a low latitude, Milyang ($35^{\circ}$30'N). The crude protein content was highest in Geomjeongkong # 3 (43.9%) and crude oil content was highest in Geomjeongkong # 4 (21.8%) among the five cultivars. Crude protein and oil contents in black soybean cultivars except Geomjeongkong # 4 were not significantly different between high latitude and low latitude. In most black soybean cultivars grown at high latitude, oleic acid content was higher, while linoleic acid, and linolenic acid contents were lower compared to low latitude. Sucrose content in Geomjeongkong # 3, raffinose contents in Geomjeongkong # 3, # 4, Ilpumgeomjeongkong, and Cheongjakong, and stachyose content in Geomjeongkong # 1 grown at low latitude was higher compared to high latitude. The variations of crude protein, crude oil and fatty acid contents seemed to be affected by genotype than growing locations according to different latitude as they did not show the significant interaction between cultivars and locations. In contrast, the variations of glucose, sucrose, and stachyose contents maybe affected by environmental condition as different latitude than the genotype because they showed the significant interaction between cultivars and locations.

• Journal of Astronomy and Space Sciences
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• v.37 no.2
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• pp.85-94
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• 2020

Equatorial noise, also known magnetosonic waves (MSWs), are one of the frequently observed plasma waves in Earth's inner magnetosphere. Observations have shown that wave amplitudes maximize at the magnetic equator with a narrow extent in their latitudinal distribution. It has been understood that waves are generated from an equatorial source region and confined within a few degrees magnetic latitude. The present study investigates whether the MSW instability and saturation amplitudes maximize at the equator, given an energetic proton ring-like distribution derived from an observed wave event, and using linear instability analysis and particle-in-cell simulations with the plasma conditions at different latitudes along the dipole magnetic field line. The results show that waves initially grow fastest (i.e., with the largest growth rate) at high latitude (20°-25°), but consistent with observations, their saturation amplitudes maximize within ±10° latitude. On the other hand, the slope of the saturation amplitudes versus latitude revealed in the present study is not as steep as what the previous statistical observation results suggest. This may be indicative of some other factors not considered in the present analyses at play, such as background magnetic field and plasma inhomogeneities and the propagation effect.