• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.6
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• pp.253-266
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• 2020

The extended slip-weakening model was investigated by using a compiled set of source-spectrum-related parameters, i.e. seismic moment M_o, S-wave velocity V_s, corner-frequency f_c, and source-controlled high-cut frequency fmax, for 113 shallow crustal earthquakes (focal depth less than 25 km, M_W 3.0~7.5) that occurred in Japan from 1987 to 2016. The investigation was focused on the characteristics of stress drop, radiation energy-to-seismic moment ratio, radiation efficiency, and fracture energy release rate, G_c. The scaling relationships of those source parameters were also investigated and compared with those in previous studies, which were based on generally used singular models with the dimensionless numbers corresponding to f_c given by Brune and Madariaga. The results showed that the stress drop from the singular model with Madariaga's dimensionless number was equivalent to the breakdown stress drop, as well as Brune's effective stress, rather than to static stress drop as has been usually assumed. The scale dependence of stress drop showed a different tendency in accordance with the size category of the earthquakes, which may be divided into small-moderate earthquakes and moderate-large earthquakes by comparing to M_o = 10¹⁷~10¹⁸ Nm. The scale dependence was quite similar to that shown by Kanamori and Rivera. The scale dependence was not because of a poor dynamic range of recorded signals or missing data as asserted by Ide and Beroza, but rather it was because of the scale dependent V_r-induced local similarity of spectrum as shown in a previous study by the authors. The energy release rate G_c with respect to breakdown distance D_c from the extended slip-weakening model coincided with that given by Ellsworth and Beroza in a study on the rupture nucleation phase; and the empirical relationship given by Abercrombie and Rice can represent the results from the extended slip-weakening model, the results from laboratory stick-slip experiments by Ohnaka, and the results given by Ellsworth and Beroza simultaneously. Also the energy flux into the breakdown zone was well correlated with the breakdown stress drop, ${\tilde{e}}$ and peak slip velocity of the fault faces. Consequently, the investigation results indicate the appropriateness of the extended slip-weakening model.

• Journal of architectural history
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• v.12 no.3
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• pp.163-179
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• 2003

The records of about 60 travel essays of the Hall of Bhaisajyaguru(Healing) Budda which was built in Chung Yang Temple passed down since 1525. The chronological change of that Hall architecture according to each period was traced upon. The building structure of the Hall of Bhaisajyaguru Budda which has a roundabout way, and 6 pillars inside, sometimes each 6 pillars inside and outside is hexagonal, one story building in Japanese colonial period(picture 3-1) or the present(picture 3-3). The panaromic picture of Chung Yang Temple shows no alterations of the layout of buildings(picture 1-1), in which the Hall of $Praj{\tilde{n}}{\bar{a}}$(般若殿), the main building in the center and the Hall of Bhaisajyaguru(Healing) Budda, three story stone pagoda, stone lighthouse in front of it became the central axis. The Hall of Bhaisajyaguru(Healing) Budda remained as it was until Japanese invasions in 1592 and 1597. However, it was greatly damaged by the flood in 1717. It was newly built by Lee Ha Gon's leading in 1717-1732. At that time, the interior design was changed. With Bhaisajyaguru(Healing) Budda, 53 Buddhas and ${\acute{S}}arira$ of Stone stupa which show itself by the flood in 1717 was located in the image of the Mountain of Chunchuk or Cheontae like Yu Jeom Temple. The doors of this Hall are located in the front and back. In the four walls each, two realistic and cubic buddhism pictures were drawn, The color of those picture was partly taken off in 1671 and repainted in 1714. The new building in 1717-1732 regained its colorful appearance. However, the names written beside each Images of Buddha disappeared. The notable remark in these records is that some of these travel essays in 17th-18th centuries was calling this hexagonal hall as the octagonal one. It is very important records because it means that before 1525 the octagonal hall might have existed. Chung Yang Temple was rebuilt between 1976 and 1985 after the destruction in the Korean War. After the records are carefully read, the full scale excavation about this historic site was not done yet. The interesting issue of the existence of octagonal building will be resolved by the full scale excavation.

• Journal of the Korean earth science society
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• v.35 no.4
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• pp.249-258
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• 2014

Despite the greenhouse gases like carbon dioxide have steadily increased in atmosphere, the overall trend of the global average surface air temperature has stalled during the last decade (2002-present). This phenomenon is often called hiatus or warming pause, which is challenging the prevailing view that anthropogenic forcing causes warming environment. Our study characterized the hiatus by analyzing the HadGEM2-AO (95 yrs) simulation data based on RCP8.5 scenario. The PC2 time series from the EOF of the zonal mean vertical ocean temperature has been defined as the index that represents the warming pause. The relationship between the hiatus, ENSO and the changes in climate system are identified by utilizing the newly defined PC2. Since the La Nina index (defined as the negative of NINO3 index) leads PC2 by about 11 months, it may be possible that the La Nina causes the warming to be interrupted. We also show that the cooling of the climate system closed tied to the heat penetration into the deep ocean, indicating the weakening the warming rate is due to the oceanic heat uptake. Finally, the global warming hiatus is characterized by the anomalous warming in Arctic region as well as the intensification of the trade wind in the equatorial Pacific.

• Korean Journal of Materials Research
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• v.20 no.11
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• pp.575-580
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• 2010

The microstructure and positive temperature coefficient of resistivity (PTCR) characteristics of 0.1 mol%$Na_2Ti_6O_{13}$ doped $0.94BaTiO_3-0.06(Bi_{0.5}Na_{0.5})TiO_3$ (BBNT-NT001) ceramics sintered at various temperatures from $1200^{\circ}C$ to $1350^{\circ}C$ were investigated in order to develop eco-friendly PTCR thermistors with a high Curie temperature ($T_C$). Resulting thermistors showed a perovskite structure with a tetragonal symmetry. When sintered at $1200^{\circ}C$, the specimen had a uniform microstructure with small grains. However, abnormally grown grains started to appear at $1250^{\circ}C$ and a homogeneous microstructure with large grains was exhibited when the sintering temperature reached $1325^{\circ}C$. When the temperature exceeded $1325^{\circ}C$, the grain growth was inhibited due to the numerous nucleation sites generated at the extremely high temperature. It is considered that $Na_2Ti_6O_{13}$ is responsible for the grain growth of the $0.94BaTiO_3-0.06(Bi_{0.5}Na_{0.5})TiO_3$) ceramics by forming a liquid phase during the sintering at around $1300^{\circ}C$. The grain growth of the BBNT-NT001 ceramics was significantly correlated with a decrease of resistivity. All the specimens were observed to have PTCR characteristics except for the sample sintered at $1200^{\circ}C$. The BBNT-NT001 ceramics had significantly decreased $\tilde{n}_{rt}$ and increased resistivity jump with increasing sintering temperature at from $1200^{\circ}C$ to $1325^{\circ}C$. Especially, the BBNT-NT001 ceramics sintered at $1325^{\circ}C$ exhibited superior PTCR characteristics of low resistivity at room temperature ($122\;{\Omega}{\cdot}cm$), high resistivity jump ($1.28{\times}10^4$), high resistivity temperature factor (20.4%/$^{\circ}C$), and a high Tc of $157.9^{\circ}C$.

• Atmosphere
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• v.17 no.3
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• pp.299-314
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• 2007

The purpose of this study is to summarize tropical cyclone activity in 2006. Twenty three tropical cyclones of tropical storm (TS) intensity or higher formed in the western North Pacific and the South China Sea in 2006. The total number is less than the thirty-year (1971~2000) average frequency of 26.7. Out of twenty three tropical cyclones, fifteen cyclones reached typhoon (TY) intensity, while the rest eight cyclones only reached severe tropical storm (STS) and tropical storm (TS) intensity - three STS and five TS storms. The tropical cyclone season in 2006 began in May with the formation of CHANCHU (0601). The convective activity was slightly inactive around the Philippines from late June to early August. In addition, subtropical high was more enhanced than normal over the south of Japan from May to early August. Consequently, most tropical cyclones formed over the sea east of the Philippines after late June, and many of them moved westwards to China. CHANCHU (0601), BILIS (0604), KAEMI (0605), PRAPIROON (0606) and SAOMI (0608) brought damage to China, the Philippines, and Vietnam. On the other hand, EWINIAR (0603) moved northwards and hit the Republic of Korea, causing damage to the country. From late August to early September, convective activity was temporarily inactive over the sea east of the Philippines. However, it turned active again after late September. Subtropical high was weak over the south of Japan after late August. Therefore, most tropical cyclones formed over the sea east of the Philippines and moved northwards. WUKONG (0610) and SHANSHAN (0613) hit Japan to bring damage to the country. On the other hand, XANGSANE (0615) and CIMARON (0619) moved westwards in the South China Sea, causing damage to the Philippines, Thailand, and Vietnam. Another special feature in 2006 tropical cyclone activity is that IOKE (0612) formed in the central North Pacific crossed 180 degree longitude and moved into the western North Pacific. It has been four years since HUKO (0224) in 2002.

• Atmosphere
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• v.18 no.3
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• pp.183-197
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• 2008

The purpose of this study is to summarize tropical cyclone activity in 2007. 24 tropical cyclones of tropical storm (TS) intensity or higher formed in the western North Pacific and the South China Sea in 2007. The total number is less than the thirty-year (1971~2000) average frequency of 26.7. Out of twenty four tropical cyclones, 14 TCs reached typhoon (TY) intensity, while the rest 10 only reached severe tropical storm (STS) and tropical storm (TS) intensity - four STS and six TS storms. The tropical cyclone season in 2007 began in April with the formation of KONG-REY (0701). From April to May, two TCs formed in the western North Pacific in response to enhanced convective activity there. From June to July, convective activity turned inactive over the sea around the Philippines and in the South China Sea, and the subtropical high was weak over the south of Japan. MAN-YI (0704) and USAGI (0705) moved northwestward and hit Japan, bringing serious damage to the country. After August, convective activity became enhanced over the sea east of the Philippines, and the subtropical high turned strong over the sea south of Japan. Many TCs, which formed over the sea east of the Philippines and in the South China Sea, moved westward and hit China and Vietnam. PABUK (0706), WUTIP (0707), SEPAT (0708), WIPHA (0712), LEKIMA (0714) and KROSA (0715) brought serious damage to some countries including China, the Philippines and Vietnam. On the other hand, FITOW (0709) and NARI (0711) moved northward, bringing serious damage to Japan and Korea. After HAIYAN (0716), all four TCs except FAXAI (0720) formed over the sea east of $140^{\circ}E$. Three typhoons among them affected Republic of Korea, MAN-YI (0704), USAGI (0705) and NARI (0711). Particularly, NARI (0711) moved northward and made landfall at Goheng Peninsula ($34.5^{\circ}N$, $127.4^{\circ}E$) in 1815 KST 16 September. Due to $11^{th}$ typhoon NARI, strong wind and record-breaking rainfall amount was observed in Jeju Island. It was reported that the daily precipitation was 420.0 mm at Jeju city, Jeju Island on 16 September the highest daily rainfall since Jeju began keeping records in 1927. This typhoon hit the southern part of the Korean peninsula and Jeju Island. 18 people lost their lives, 14,170 people were evacuated and US$ 1.6 billion property damage was occurred.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.241-248
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• 2002

With the structure of tilde-area computing system which Is specified by a researching team in Vrije University, Netherlands, lots of researchers and developers have been progressing the studies of global location and interconnection services of distributed objects existing in global sites. Most of them halve focused on binding services of only non-duplicated computational objects existing wide-area computing sites without any consideration of duplication problems. But all of objects existing on the earth rave the duplicated characteristics according to how to categorize their own names or properties. These objects with the same property can define as duplicated computational objects. Up to now, the existing naming or trading mechanism has not supported the binding services of duplicated objects, because of deficiency of independent location service. For this reason, we suggest a new model that can not only manages locations of duplicated objects In wide-area computing environments, but also provide minimum binding time by considering both the optimal selection of one of duplicated objects and load balance among distributed systems. Our model is functionally divided into 2 parts, one part to obtain an unique object handle of duplicated objects with same property as a naming and trading service, and the other to search one or more contact addresses by a node manager using a liven object handle, as a location service For location transparency, these services are independently executing each other. Based on our model, we described structure of wide-area integrated tree and algorithms for searching and updating contact address of distributed object on this tree. finally, we showed a federation structure that can globally bind distributed objects located on different regions from an arbitrary client object.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.375-380
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• 2002

Background: Sternal infection after open heart surgery is a serious complication associated with high rate of mortality. We reviewed the effect of improved operating room and intensive care unit un the sternal infection by analyzing the incidence and condition of that around the movement of operating room and intensive care unit in July 1997. Material and method: We reviewed a total of 453 patients. Group I contains 237 patients who underwent open heart surgery between January 1997 and December 1978 before we moved the intensive care unit and of operating room, and Group II contains 216 patients who underwent open heart surgery between January 2000 and July 2001 after we moved. We only included adult patients over age 15 who underwent cardiopulmonary bypass through median sternotomy and excluded the mortality cases except sternal infections in this study. Result: Sternal infection developed in 18 patients(8.0%) in Group I, and in only 1 patient(0.49%) in Group II. Emergency operation, cardiopulmonary bypass time, operation tilde, transfusion, tracheostomy, and reoperation are significantly associated with sternal infection among the known risk factors. The logistic regression analysis containing those six factors revealed that the movement of intensive care unit and operating roots is effective on the decreasing sternal infection(p=0.029, 95% confidence interval 0.011 ∼ 0.788). Conclusion: Although there have been studies on manly risk factors associated with the sternal infection after open heart surgery, we think that the improvement of operting room and intensive care unit is a method for decreasing the incidence of sternal infection.

• Atmosphere
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• v.19 no.2
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• pp.183-198
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• 2009

The purpose of this study is to summarize the tropical cyclone (TC) activity of 2008 over the western North Pacific including the verification of the official track and intensity forecast errors of these TCs. The TC activity - frequency, Normalized Typhoon Activity (NTA), and life span - was lower than 58-year (1951-2008) average. 22 tropical cyclones of tropical storm (TS) intensity or higher formed in the western North Pacific and the South China Sea in 2008. The total number is less than 58-year average frequency of 26.4. Out of 22 tropical cyclones, 11 TCs reached typhoon (TY) intensity, while the rest 11 TCs only reached severe tropical storm (STS) and tropical storm (TS) intensity - six STS and five TS storms. One typhoon KALMAEGI (0807) among them affected the Korea peninsula. However, no significant impact - casualty or property damage - was reported. On average of 22 TCs in 2008, the Korea Meteorological Administration (KMA) official track forecast error for 48 hours was 229 km. There was a big challenge for individual cyclones such as 0806 FENGSHEN and 0817 HIGOS presenting significant forecast error, with both intricate tracks and irregular moving speed. The tropical cyclone season in 2008 began in April with the formation of NEOGURI (0801). In May, four TCs formed in the western North Pacific in response to enhanced convective activity. On the other hand, the TC activity was very weak from June to August. It is found that the unusual anti-cyclonic circulation in the lower level and weak convection near the Philippines are dominant during summertime. The convection and atmospheric circulation in the western North Pacific contributed unfavorable condition for TC activity in the 2008 summertime. The 2008 TC activity has continued the below normal state since mid 1990s which is apparent the decadal variability in TC activity.

• Ocean and Polar Research
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• v.40 no.1
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• pp.1-13
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• 2018

Previous studies have indicated a great regional difference in Sea Level Rise (SLR) in the Pacific and it has been suggested that this is linked to climate variability over the past two decades. In this study, we seek to identify the possible linkage between regional sea level and Pacific climate variability from altimetry-based sea level data (1993-2012) and further investigate how the Pacific sea level has changed spatially and temporally over the past 60 years from long-term sea level reconstruction data (1953-2008). Based on the same method as Zhang and Church (2012), the Inter-annual Climate Index (ICI) associated with the El $Ni{\tilde{n}}o-Southern$ Oscillation (ENSO) and the Decadal Climate Index (DCI) associated with Pacific Decadal Oscillation (PDO) are defined and then the multiple variable linear regression is used to analyze quantitatively the impact of inter-annual and decadal climate variability on the regional sea levels in the Pacific. During the altimeter period, the ICI that represents ENSO influence on inter-annual time scales strongly impacts in a striking east-west "see-saw mode" on sea levels across the tropical Pacific. On the other hand, the decadal sea level pattern that is linked to the DCI has a broad meridional structure that is roughly symmetric in the equator with its North Pacific expression being similar to the PDO, which largely contributes to a positive SLR trend in the western Pacific and a negative trend in the eastern Pacific over the two most recent decades. Using long-term sea level reconstruction data, we found that the Pacific sea levels have fluctuated in the past over inter-annual and decadal time scales and that strong regional differences are presented. Of particular interest is that the SLR reveals a decadal shift and presents an opposite trend before and after the mid-1980s; i.e., a declining (rising) trend in the western (eastern) Pacific before the mid-1980s, followed by a rising (declining) trend from the mid-1980s onward in the western (eastern) Pacific. This result indicates that the recent SLR patterns revealed from the altimeters have been persistent at least since the mid-1980s.