• Journal of the Korean Geographical Society
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• v.50 no.1
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• pp.1-21
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• 2015

The present study aims to characterize the synoptic climatic patterns of winter extreme low temperature events occurred in different regions of Korea based on daily temperature data observed at 61 weather stations under the supervision of the Korea Meteorological Administation and NCEP/NCAR reanalysis I data for the recent 40 years (1973~2012) period. Analyses of daily maximum and minimum temperatures below 10th percentile thresholds show that high frequencies of winter extreme low temperature events appear across the entire regions of Korea or in either the western or eastern half region divided by major mountain ridges at the 2~7 dayintervals particularly in the first half of the winter period (before mid-January). Composite analyses of surface synoptic climatic data including sea level pressure and wind vector reveal that 13 regional types of winter extreme low temperature events in Korea are closely associated with the relative location and intensity of both the Siberian high pressure and the Aleutian low pressure systems as well as major mountain ridges. Investigations of mid-troposphere (500 hPa) synoptic climatic charts demonstrate that the blocking-like upper troposphere low pressure system advecting the cold air from the Arctic toward the Korean Peninsula may provide favorable synoptic conditions for the outbreaks of winter extreme low temperature events in Korea. These results indicate that the monitoring of synoptic scale climatic systems in East Asia including the Siberian high pressure system, the Aleutian low pressure system and upper level blocking system is critical to the improvement of the predictability of winter extreme low temperature events in Korea.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.1
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• pp.233-252
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• 2018

The first Protestant medical missionary, Horace Allen, came to Korea in 1884 and built the first western-style hospital, Jaejungwon. John Heron, Oliver Avison and other foreign medical doctors soon followed. They established hospitals and medical schools, and, by treating patients and educating native doctors, they disseminated and developed modern medicine in Korea. At the same time, they wrote letters and reports to their sponsoring agencies, as well as family and friends, thereby leaving a vast body of literature that is scattered all over the world. Since the end of the 19th century, the records left by foreign medical missionaries have been valuable resources for the study of Korean history. While all types of records, such as diaries, memoirs, reports and travel logs, are available, these tend to be exaggerated or unverifiable because they are unilateral records. In contrast, letters can be verified because they are bilateral records between the recipient and the sender, and cannot be modified or altered according to changes in circumstances. Despite the academic value of these materials, however, there have been insufficient efforts to discover or identify these primary data sources, or to systematically organize them for scholars. This paper identified 49 archival collections from 29 institutions in North America. After analyzing their academic value, the paper will explore digital humanities options in utilizing the letters for future scholarship.

• Journal of the Korean Geographical Society
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• v.41 no.4 s.115
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• pp.435-456
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• 2006

This study examines the long-term spatial patterns and recent trends of seasonal onsets and durations defined by daily temperatures in South Korea for the period 1973-2004. Spatially, spring and winter onset dates show approximately 44 day and 63 day maximum difference respectively between south and north (Seongsanpo to Daegwallryeong) attributable to the impacts of latitudes and altitudes. In contrast, summer onset, which is more affected by proximity to oceans and altitudes than by latitudes, begins earlier in interior low elevated areas than in the coastal areas but earliest at higher latitudes than Jeiu Island. Five climatic types regarding the seasonal cycles in South Korea are spatially clustered according to the combination of longer seasonal durations. As a reflection of recent climate changes on seasonal cycles in South Korea, winter duration was shortened by 10 days during the post-1988 period due to a late winter onset of 4 days and an early spring onset of 6 days. The winter reduction began in the southern regions of the Korean Peninsula in the mid-1980s and spread northward during the 1990s period, ultimately appearing everywhere. In urbanized cities, where much of the surface is covered with asphalt or concrete, the winter reduction was intensified and summer duration was locally incremented. The reduced winter duration in recent decades shows significant teleconnections with variations of geopotential height (925hPa) in the eastern Arctic region ($0-90^{\circ}E$, $65-85^{\circ}N$) during the cold season. The reduction in winter duration in South Korea agrees with results in overall global warming trends as a climate change signal.

• Journal of Korean Philosophical Society
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• v.130
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• pp.1-22
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• 2014

Li Zehou(李澤厚) regards Chuang-tzu's fatalism as a kind of pessimism and slavish conformism. The main issue of this paper is to opposes Li Zehou(李澤厚)'s view, and reveal that Chuang-tzu's fatalism is not the negative and slavish conformism but the true positivism of the fate. These Chuang-tzu's fatalism can be conceptualized as a 安之若命. When the human was faced with unavoidable fate, Chuang-tzu's 安之若命 is not pessimistically surrender itself to the fate such as a slave, but pleasantly accepts and affirms the fate. Now, the next three process proves that Chuang-tzu's 安之若命 affirms the fate.The attitude of 安之若命, First, takes the unavoidable(不得已) fate as it is. Second, it resolves a humane 'sadness and joy(哀樂)' through 'the forgetting(忘).' Third, it understands the life and death, the change of world, the human body as the stream of energy(氣). Fourth, in conclusion, it affirms the fate by these processes. These point of view can conceptualize as Chuang-tzu's Amor Fati. That is to say, Chuang-tzu' 安之若命 is not a pessimistic but a positive view of the fate.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.460-464
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• 2008

To improve and optimize user interfaces of the system, the accurate understanding of users' behavior is an essential prerequisite. Direct questions depend on user' s ambiguous memory and usability tests depend on the researchers' intention instead of users'. Furthermore, they do not provide with natural context of use. In this paper we described the work which examined users' behavior through log analysis in their own environment. 50 users were recruited by consumer segmentation and they were downloaded logging-software in their mobile phone. After two weeks, logged data were gathered and analyzed. The complementary methods such as a user diary and an interview were conducted. The result of the analysis showed the frequency of menu and key access, used time, data storage and several usage patterns. Also, it was found that users could be segmented into new groups by their usage patterns. The improvement of the mobile phone user interface was proposed based on the result of this study.

• Composites Research
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• v.23 no.2
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• pp.10-16
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• 2010

$Al_2O_3$ fiber and SiC particle hybrid metal matrix composites (MMCs) were manufactured by squeeze casting method investigated for their tribological properties. The pin specimens had different ratios of fiber to particle content but their total weight fraction was constant at 20 wt. %. Tribological tests were performed with a pin-on-disk friction and wear tester. The investigation of the dry tribological characteristics of hybrid MMCs were carried out at room temperature and elevated temperature of$100^{\circ}C$ and$150^{\circ}C$. The morphologies of worn surfaces were examined by scanning electron microscope (SEM) to observe tribological characteristics and investigate wear behavior. The results revealed that the wear resistance improved with the content of SiCp increased of the planar random (PR) MMCs at room temperature. At the elevated temperature, it revealed that the wear resistance of normal (N) MMCs was superior to that of the PR-MMCs due to PR-fibers were easily pulled out holistically from the worn surface. Meanwhile, the coefficient of friction decreased with the temperature increasing.

• Korean journal of applied entomology
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• v.43 no.1
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• pp.21-26
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• 2004

These studies were carried out to investigate the oviposition and host feeding characteristics of Neochrysocharis formosa Westwood, an endoparasitoid of Liriomyza trifolii. N. formosa female oviposited inside the abdomen at the rear end of the host larva. Number of eggs and host feeding per day of N. formosa tended to increase as temperatures go up. The ratio of oviposition and host feeding of N. formosa were 0.5, 0.9, 1.0 and 1.0 at 15, 20, 25, and 30$^{\circ}C$, respectively. In 25$^{\circ}C$, number of eggs and host feeding were 176.0 and 188.7, respectively, and aduly female longevity was 11.8 days. N. formosa female preferred to the 3rd rather than 1st and 2nd larva for oviposition and host feeding.

• Journal of Astronomy and Space Sciences
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• v.21 no.1
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• pp.39-72
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• 2004

We present a more complete and accurate catalogue of astronomical records far meteor showers and meteor storms appeared in primary official Korean history books, such as Samguk-sagi, Koryo-sa, Seungjeongwon-ilgi, and Chosen-Wangjo-Sillok. So far the catalogue made by Imoto and Hasegawa in 1958 has been widely used in the international astryonomical society. The catalogue is based on a report by Sekiguchi in 1917 that is mainly based on secondary history books. We observed that the catalogue has a number of errors in either dates or sources of the records. We have thoroughly checked the primary official history books, instead of the secondary ones, in order to make a corrected and extended catalogue. The catalogue contains 25 records of meteor storms, four records of intense meteor-showers, and five records of usual showers in Korean history. We also find that some of those records seem to correspond to some presently active meteor showers such as the Leonids, the Perseids, and the n -Aquarids-Orionids pair. However, a large number of those records do not correspond to suck present showers. This catalogue we obtained can be useful for various astrophysical studies in the future.

• Journal of the Korean earth science society
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• v.36 no.4
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• pp.315-329
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• 2015

We investigated the characteristics of meteorological conditions related to the strong downslope wind over the leeward side of the Taebaek Mountains during the period 2005~2010. The days showing the strong wind exceeding $14ms^{-1}$ in Gangwon province were selected as study cases. A total of 15 days of strong wind were observed at Sokcho, Gangneung, Donghae, and Taebaek located over the Yeongdong region. Seven cases related to tropical cyclone (3 cases) and heavy snowfall (2 cases) and heavy rainfall (2 cases) over the Yeongdong region were excluded. To investigate the characteristics of the remaining 8 cases, we used synoptic weather chart, Sokcho radiosonde, Gangneung wind profiler and numerical model. The cases showed no precipitation (or ${\leq}1mm\;day^{-1}$). From the surface and upper level weather chart, we found the pressure distribution of southern high and northern low pattern over the Korean peninsula and warm ridge over the Yeongdong region. Inversion layer (or stable layer) and warm ridge with strong wind were located in about 1~3 km (925~700 hPa) over mountains. The Regional Data Assimilation and Prediction System (RDAPS) indicated that warm core and temperature ridge with horizontal temperature gradient were $0.10{\sim}0.23^{\circ}C\;km^{-1}$ which were located on 850 hPa pressure level above mountaintop. These results were summarized as a forecasting guidance of downslope windstorm in the Yeongdong region.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.322-340
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• 2021

Due to climate change and its consequential spring temperature rise, flowering time of Robinia pseudoacacia has advanced and a simultaneous blooming phenomenon occurred in different regions in South Korea. These changes in flowering time became a major crisis in the domestic beekeeping industry and the demand for accurate prediction of flowering time for R. pseudoacacia is increasing. In this study, we developed and compared performance of four different models predicting flowering time of R. pseudoacacia for the entire country: a Single Model for the country (SM), Modified Single Model (MSM) using correction factors derived from SM, Group Model (GM) estimating parameters for each region, and Local Model (LM) estimating parameters for each site. To achieve this goal, the bloom date data observed at 26 points across the country for the past 12 years (2006-2017) and daily temperature data were used. As a result, bloom dates for the north central region, where spring temperature increase was more than two-fold higher than southern regions, have advanced and the differences compared with the southwest region decreased by 0.7098 days per year (p-value=0.0417). Model comparisons showed MSM and LM performed better than the other models, as shown by 24% and 15% lower RMSE than SM, respectively. Furthermore, validation with 16 additional sites for 4 years revealed co-krigging of LM showed better performance than expansion of MSM for the entire nation (RMSE: p-value=0.0118, Bias: p-value=0.0471). This study improved predictions of bloom dates for R. pseudoacacia and proposed methods for reliable expansion to the entire nation.