• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.66-79
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• 2022

In the mid-Kofun period, the technology employed in the southern part of the Korean Peninsula had reached the Japanese archipelago, and a Japanese-style unglazed earthenware called Sueki was produced. During the early period of the spread of technology, regional elements from all over the Korean Peninsula remained strong, with production on the Japanese archipelago carried out only in very limited regions. After that, production in all parts of the archipelago began gradually. The Sueki culture was introduced to the Japanese archipelago with the technology of the Korean Peninsula; however, many excavations have been reported in the Korean Peninsula(these excavations are even called Suekitype). Many of these excavations were conducted in Jeolla-do, Yeongnam, and the Yeongsan River basin. As revealed in previous studies, however, many imitations were excavated around Jeolla-do, while Sueki of the Japanese archipelago were excavated from tombs in the Yeongnam area. The excavation period was generally from the late 5^th century to the early 6^th century(especially from the TK23 to MT15 stage), which is fundamentally different from that of Jeolla-do. Regarding the locations where Sueki were excavated, the majority were found in the tombs of local authorities. They were rarely excavated from the tombs of the royal people. Furthermore, there is no evidence of special meaning given to funeral ceremonies or Sueki in the Japanese archipelago form; therefore, most of them are thought to have been treated the same as unglazed earthenware. Considering the tombs as a whole, influential people(groups, families, and forces) were not only connected to certain areas of the Gaya region but also had complex and larger relationships. In other words, the Sueki excavated from the Yeongnam area may reflect the rise and fall of the forces in each Gaya region and the changes of the Yeongnam period. The role of negotiation and exchange can be seen not only from the fact that influential people in the central government of the Gaya region were involved but also from the existence of areas(groups, families, forces) discovered in the Gaya region indicating mutual relationships.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.215-223
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• 2013

The objective of this study was to evaluate fish passage efficiency, based on fish-trap monitoring methodology, in the fishway of Seungchon Weir, which was constructed on the lower region of Yeongsan River in 2011. Seasonal patterns and diel variations of fish movements, fish fauna, and compositions in the fishway were analyzed in relation to the current velocity and location of the trap-setting in the fishway. For the analysis, we conducted seven times surveys in 2012 on the fishway and also conducted intensive monitoring of the fishway as 3 hrs interval for the diel variations of fish fauna and compositions in the fishway. According to the fish-trap monitoring methodology, the total number of fish species was 13 species, which was a 43.3% of the total. Most dominant fish used the fishway was Squalidus chankaensis tsuchigae and the relative abundance of the species used the fishway was 33.5% of the total. The season and time zone (in diel variation) observed most frequently in the fishway were July and 18:00-21:00 PM, respectively. The fish movements and use-rates of fishway varied depending on the locations of trap-setting; Fish biomass and the number of species were statistically (p < 0.05) greater in the most right or left-sided traps than in the mid-traps. Also, fish movements and use-rates of fishway were influenced by current velocity on the fishway; fish in the fishway preferred the low current velocity (mean 0.71 m/sec) than the high current velocity (mean 1.13 m/sec). Further long-term studies should be monitored for the efficiency evaluations of the fishway.

• The Journal of Fisheries Business Administration
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• v.37 no.2 s.71
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• pp.111-139
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• 2006

Cold storage warehouse industry in Japan has been extended in its scale in terms of both the number of storages and cold storage capacity in order to meet the extended reproduction of the marine products industry. However, increasing total amount of the stored goods since mid 80s led to relative decrease of marine products while the number of storages was remained the same or decreased, though cold storage capacity was gradually increased and is maintained the increase of the average cold storage capacity. As structural change in the cold storage warehouse industry emerges, cold storage warehouses require new approach to individual storage management with 1)diversity of the stored goods; 2) more competition due to increase of the cold storage capacity; and 3) sizing of the average cold storage capacity. Therefore, this study analyzed how cold storage warehouse management activity with individual storage sizing changes; and significance of sizing and functional change in cold storage warehouses experiencing sizing, by observing leading cold storage warehouse industry of the metropolitan area in Japan. In conclusion, reorganization of cold storage warehouse industry in the metropolitan area in Japan can be summarized as follows: First, competition among cold storage warehouses in the metropolitan area in Japan is not simply limited to storage industry but extended to establishment and securing physical distribution function. Second, since cold storage warehouse industry is in Scrap & Build phase, decision of management executives on whether taking direction to maintain/continue enhancement of physical distribution function may cause drastic reorganization in the cold storage warehouse industry, Third, since profit of physical distribution management based on cold storage warehouses is insignificant, it is not easy to accomplish expected management outcome, Fourth, today's cold storage warehouse industry mainly characterized by diversity of the stored goods needs facility reorganization with comprehensive and functional integration covering from F class cold storage capacity to F&C class.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.6
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• pp.277-283
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• 2020

In order to improve the ground-motion prediction equation, which is an important factor in seismic hazard assessment, it is essential to obtain good quality seismic data for a region. The Korean Peninsula has an environment in which it is difficult to obtain strong ground motion data. However, because digital seismic observation networks have become denser since the mid-2000s and moderate earthquake events such as the Odaesan earthquake (Jan. 20, 2007, M_L 4.8), the 9.12 Gyeongju earthquake (Sep. 12, 2016, M_L 5.8), and the Pohang earthquake (Nov. 15, 2017, M_L 5.4) have occurred, some good empirical data on ground motion could have been accumulated. In this study, we tried to build a ground motion database that can be used for the development of the ground motion attenuation equation by collecting seismic data accumulated since the 2000s. The database was constructed in the form of a flat file with RotD50 peak ground acceleration, 5% damped pseudo-spectral acceleration, and meta information related to hypocenter, path, site, and data processing. The seismic data used were the velocity and accelerogram data for events over M_L 3.0 observed between 2003 and 2019 by the Korean National Seismic Network administered by the Korea Meteorological Administration. The final flat file contains 10,795 ground motion data items for 141 events. Although this study focuses mainly on organizing earthquake ground-motion waveforms and their data processing, it is thought that the study will contribute to reducing uncertainty in evaluating seismic hazard in the Korean Peninsula if detailed information about epicenters and stations is supplemented in the future.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.5 s.51
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• pp.11-23
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• 2006

This paper evaluates the seismic response of multi-span prestressed concrete girder bridges typically found in the New Madrid Seismic Zone region of the central United States. Using detailed nonlinear analytical models and synthetic ground motion records for Memphis, TN, nonlinear response history analyses are performed for two levels of ground motion: 10% probability of exceedance (PE) in 50 years, and 2% probability of exceedance (PE) in 50 years. The results show that the bridge performance is very good fur the 10% PE in 50 years ground motion level. However, the performance for the 2% PE in 50 years ground motion is not so good because it results in highly inelastic behavior of the bridge. Impact between decks results in large ductility demands on the columns, and failure of the bearings that support the girders. It is found that making the superstructure continuous, which is commonly performed for reducing dead load moments and maintenance requirements, results in significant improvement in the seismic response of prestressed concrete girder bridges.

• Atmosphere
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• v.25 no.1
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• pp.155-167
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• 2015

A dynamical seasonal prediction system for boreal winter utilizing cryospheric information was developed. Using the Community Atmospheric Model, version3, (CAM3) as a modeling system, newly developed snow depth initialization method and sea ice concentration treatment were implemented to the seasonal prediction system. Daily snow depth analysis field was scaled in order to prevent climate drift problem before initializing model's snow fields and distributed to the model snow-depth layers. To maximize predictability gain from land surface, we applied one-month-long training procedure to the prediction system, which adjusts soil moisture and soil temperature to the imposed snow depth. The sea ice concentration over the Arctic region for prediction period was prescribed with an anomaly-persistent method that considers seasonality of sea ice. Ensemble hindcast experiments starting at 1st of November for the period 1999~2000 were performed and the predictability gain from the imposed cryospheric informations were tested. Large potential predictability gain from the snow information was obtained over large part of high-latitude and of mid-latitude land as a result of strengthened land-atmosphere interaction in the modeling system. Large-scale atmospheric circulation responses associated with the sea ice concentration anomalies were main contributor to the predictability gain.

• Physical Therapy Rehabilitation Science
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• v.7 no.3
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• pp.95-101
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• 2018

Objective: To determine if the provision of visual biofeedback using real-time rehabilitative ultrasound imaging (RUSI) enhances the acquisition and retention of diaphragm muscle recruitment during exercise. Design: Two group pretest posttest design. Methods: Thirty healthy subjects were randomly assigned to the verbal feedback group (VG, n=15) or the visual and verbal feedback group (VVG, n=15). The VG performed breathing exercises 10 times with verbal feedback, and the VVG also performed breathing exercises 10 times with verbal feedback and visual feedback with the use of RUSI to measure changes in diaphragm thickness (DT). For DT, the mid-axillary lines between ribs 8 and 9 on both sides were measured in standing, and then the chest wall was perpendicularly illuminated using a linear transducer with the patients in supine to observe the region between rib 8 and 9 and to obtain 2-dimensional images. DT was measured as the distance between the two parallel lines that appeared bright in the middle of the pleura and the peritoneum. After one week, three repetitions (follow-up session) were performed to confirm retention effects. Intra- and between- group percent changes in diaphragm muscle thickness were assessed. Results: In the VVG, the intervention value had a medium effect size compared to the baseline value, but the follow-up value decreased to a small effect size. In the between-group comparisons, during the intervention session, the VVG showed no significant effect on percent change of DT but had a medium effect size compared to the VG (p=0.050, Cohen's d=0.764). During the follow-up session, retention effect did not persist (p=0.311, Cohen's d=0.381). Conclusions: RUSI can be used to provide visual biofeedback and improve performance and retention in the ability to activate the diaphragm muscle in healthy subjects. Future research needs to establish a protocol for respiratory intervention to maintain the effect of diaphragmatic breathing training using RUSI with visual feedback.

• Journal of The Korean Astronomical Society
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• v.51 no.4
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• pp.89-110
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• 2018

Active Galactic Nucleus (AGN) variability can be used to study the physics of the region in the vicinity of the central black hole. In this paper, we investigated intra-night optical variability of AGN in the COSMOS field in order to understand the AGN instability at the smallest scale. Observations were performed using the KMTNet on three separate nights for 2.5 to 5 hours at a cadence of 20 to 30 min. We find that the observation enables the detection of short-term variability as small as ~ 0.02 and 0.1 mag for R ~ 18 and 20 mag sources, respectively. Using four selection methods (X-rays, mid-infrared, radio, and matching with SDSS quasars), 394 AGN are detected in the $4deg^2$ field of view. After differential photometry and ${\chi}^2$-test, we classify intra-night variable AGN. The fraction of variable AGN (0-8%) is statistically consistent with a null result. Eight out of 394 AGN are found to be intra-night variable in two filters or two nights with a variability level of 0.1 mag, suggesting that they are strong candidates for intra-night variable AGN. Still they represent a small population (2%). There is no sub-category of AGN that shows a statistically significant intra-night variability.

• Journal of Ginseng Culture
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• v.2
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• pp.9-16
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• 2020

Ginseng was first addressed ever in the medical record in HyangYakGooGupBang (鄕藥救急方), the oldest Korean medical book published in Kingdom of Goryeo (918-1392) when Ganghwa was the provisional capital city at the time. It is believed that ginsengs in Ganghwa were planted and cultivated from 1100s. Intensive ginseng production in Ganghwa began when Ganghwa became the special district of the Kaesong Ginseng Union (開城人蔘組合) in 1920s, this intensive production continued till the Korean War in 1950. After the Korean War ended in 1953, ginseng production was resumed. In 1967, Ganghwa Ginseng Association (江華蔘業組合) was founded. The total acreage of ginseng harvested was nearly 200 ha in 1967 and it increased to ha 900 in 1974. By mid-1970s, Ganghwa became the largest ginseng region in Korea by total production and acreage. Most of ginseng roots cultivated in Ganghwa are six years old. Ganghwa, which was already well-known for red ginseng productions, has become even more famous for ginseng production.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.3
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• pp.310-320
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• 2000

Statement of the problem. The record base in fabricating procedures of the complete denture, as a temporary form for reproducing denture base, is used to record upper and lower jaw relation and to align artificial teeth and try-in it in the mouth. The accuracy of jaw relation record is affected by the accuracy, stiffness and stability of the record base. So, the accuracy of record base is the most important requirements of jaw relation records. Purpose of study. The purpose of this study was to evaluate the gap that occurred over the palatal area of a maxillary record base fabricated with autopolymerizing resin and light-curing resin. Methods/material. The maxillary record bases were fabricated out of autopolymerizing resin that is used the most frequently in clinics and light-curing resin that attracts special attention for its several merits. The light-curing resin was made by two kinds of polymerization methods, which are one step curing method and multiple step curing method. All record bases were cut in certain positions of the master cast 1 hour and 1 day later after fabrication and the accuracy of the master cast was measured and analyzed with a microscope. Results. A pattern of gap formation between the record base and the maxillary cast was observed in all specimens. According to kinds of resins, autopolymerizing resin was significantly more accurate than light-curing resin. There was no statistical difference according to time lapse, and in all three groups, the maximum discrepancy occurred at the posterior border in the mid-palatal region. Conclusion. The autopolymerizing resin is better than light-curing resin, and multiple step curing method is more accurate than one step curing method when using light-curing resin.