• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.79-84
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• 2003

This study revealed the differences in runoff processes of granite drainage basins in Korea and Mongolia by hydrological measurements in the field. The experimental drainage basins are chosen in Korea (K-basin) and Mongolia (M-basin). Occurrence of intermittent flow in K-basin possibly implies that very quick discharge dominates. The very high runoff coefficient implies that most of effective rainfall quickly discharge by throughflow or pipeflow. The Hortonian overlandflow is thought to almost not occur because of high infiltration capacity originated by coarse grain sized soils of K- basin. Very little baseflow and high runoff coefficient also suggest that rainfall almost does not infiltrate into bedrocks in K-basin. Flood runoff coefficient in M-basin shows less than 1 %. This means that most of rainfall infiltrates or evaporates in M-basin. Runoff characteristics of constant and gradually increasing discharge imply that most of rainfall infiltrates into joint planes of bedrock and flow out from spring very slowly. The hydrograph peaks are sharp and their recession limbs steep. Very short time flood with less than 1-hour lag time in M-basin means that overland flow occurs only associating with rainfall intensity of more than 10 mm/hr. When peak lag time shows less than 1 hour for the size of drainage area of 1 to 10 km2, Hortonian overland flow causes peak discharge (Jones, 1997). The results of electric conductivity suggest that residence time in soils or weathered mantles of M-basin is longer than that of K-basin. Qucik discharge caused by throughflow and pipeflow occurs dominantly in K-basin, whereas baseflow more dominantly occur than quick discharge in M-basin. Quick discharge caused by Hortonian overlandflow only associating with rainfall intensity of more than 10 mm/hr in M-basin.

• Journal of architectural history
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• v.13 no.3
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• pp.51-67
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• 2004

The purpose of this study is to bring light on the characteristics of the transition in the Ddeulzip. The subject of this study is clan village of Pungsan Kim's family in Andong Cultural Area. Architectural transition of Ddeulzip is analyzed into three part. The first part is settlement of family. In this process, there is a background and many types of settlement. The second part is the extension of family. The extensional types are 'near-by branch' and 'far-away branch'. The last part is variation of housing. Spacial requests of residence are changed endlessly. Thus the spacial types of Ddeulzip are changed by the construction time of building. In many case, we couldn't decide the building period. The genealogy of Chosun Dynasty is the base of family history. In this study, the construction activity of Ddeulzip is based on the genealogy. The phylogenetic tree of Ddeulzip in clan village is constructed by the genealogy. The figures of the type of bunch of grapes is made by phylogenetic tree based on the genealogy. Omi Village in Andong was settled at first in the 15C. The cause of settlement is the aim of escape from political oppression. For long time, Omi Village is developed gradually. There area is divided in some small family boundary. There spacial types are contained the characteristics of many times. Orock Village in Bonghwa is settled for search of best environment in the last of 17C. At that time, a lot of families of same clan are gathered in that village. For short time, Orock Village is enlarged quickly. Thus there spacial type is similar each other. But boundary of entire space of outdoor is constructed clearly by pavilion area, housing area and sanctuary area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.69-77
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• 1997

A 12-cm long sediment core was collected from a station in Lake Shihwa where high salinity-anoxic deep water is isolated from low salinity-oxic surface water by a strong halocline barrier. Unprecedented concentrations of porewater ammonia and lead are encountered: at 9 cm sediment depth ammonia builds up to 1420 ${\mu}M$ and at 3 cm lead to 1348 nM. As they are stable in anoxic condition, high concentrations of ammonia and lead suggest a development of notorious anoxic condition in the benthic environment of the lake. The degree of pollution of the deep water is likely to be directly proportional to the magnitude of benthic flux, because the deep water is isolated from the surface water by the halocline. Apparent coincidence of the ammonia residence time in the deep water with the elapsing time after the completion of the artificial lake construction, as about three years, suggests that the deep water pollution is being progressed entirely by benthic flux at least with respect to ammonia. The residence time for lead is such a short 20 days that it suggests a rapid return of the bottom water lead, which is originated from porewater by benthic flux, back to sediments probably as metal sulfide phases. The speculation on the return of lead as sulfide phases is likely to be supported by high concentration of hydrogen sulfide in the deep water and by high sinking rate of non-organic particles in Lake Shihwa.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.153-160
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• 2021

Nitrous oxide is a global warming substance and is known as the main cause of the destruction of the ozone layer because its global warming effect is 310 times stronger than carbon dioxide, and it takes 120 years to decompose. Therefore, in this study, we investigated the characteristics of NOx emission from N2O reduction by thermal decomposition of N2O. Bunsen premixed flames were adopted as a heat source to form a high-temperature flow field, and the experimental variables were nozzle exit velocity, co-axial velocity, and N2O dilution rate. NO production rates increased with increasing N2O dilution rates, regardless of nozzle exit velocities and co-axial flow rates. For N2O, large quantities were emitted from a stable premixed flame with suppressed combustion instability (Kelvin Helmholtz instability) because the thermal decomposition time is not sufficient with the relatively short residence time of N2O near the flame surface. Thus, to improve the reduction efficiency of N2O, it is considered effective to increase the residence time of N2O by selecting the nozzle exit velocities, where K-H instability is generated and formed a flow structure of toroidal vortex near the flame surface.

• Journal of architectural history
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• v.31 no.6
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• pp.69-80
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• 2022

This study explains details on Heungbokjeon during the reconstruction of Gyeongbokgung Palace in the 19th century for the first time in 273 years. Hence, the construction of a palace with more than 7,000 Kan(間) made possible in a short stretch of time. Given the fact that its existing architecture was recycled. The antecedent of Heungbokjeon(興福殿) was the Hamiljae(咸一齋) of Changuiggung(彰義宮) which served as the residence of King Yeongjo before he was enthroned. On the other hand, the Changuigung was the outset of Inpyeongwi-gung(寅平尉宮), which was built for the princesses. During the reign of King Hyojong the princess who got married must depart from the Inpyeongwi-gung. This study corroborated the undertaking of modification of its architecture frombeing asymmetrical house to symmetrical most primarily the inner part of the palace through the innovation of Changui-gung and the restoration of Hamijae to Heungbokjeon. Hence, it was confirmed that the Heungbokjeon was the only inner part of the palace that was not burned down by the 2 consecutive fires during the reign of King Gojong, to be more specific these fire happend on his 10th and 13th year of rule. Consequently, the research process of Gyeongbokgung Heungbokjeon can escalate the possibility of considering not only the reconstruction of Gyeongbokgung in the 19th century, as well as the construction of the capital city in the 17th century.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.35-41
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• 2004

The yeongok stream originates at the natural park, Mt. O-dae and flows to the East Sea of korea, normally maintaining I or II grade of water quality and its average water flux is 352,100 ㎥/d. However, the typhoon 'Rusa', which occured on 31 August 2002, changed its watercourse and configuration, and the ecosystem was deeply damaged. Moreover, the hydrological characteristics were once more transformed, and the ecosystem was secondarily damaged during repair-work of destroyed bridges and elevations. After the flood disaster, the species diversity diminished 17% for attached diatom and 44% for aquatic animals. However, the earth and sand, dug from river bed during intensive repair-work throughout the entire stream, made diversity drop to 32% for the diatom and the aquatic animals were wiped out. Especially, fishes were totally destroyed except for some species such as Moroco oxycephalus in the upper stream. The yeongok stream has little contamination source and short water residence time due to the short length and rapid slope, and consequently a temporary deterioration of water quality caused by repair-work may be rapidly recovered, but it needs a long time to restore the damaged ecosystem.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4D
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• pp.467-472
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• 2009

Even if Seoul City administration improved its public transportation service, transportation model share in seoul has not been increased. Subway user is also decreasing. Therefore, policy transition into TOD(Transit Oriented Development) should be applied in oder to enhance subway modal share. This paper develops a influencing model by using variables of transportation demand and supply. In addition, it provides major influencing factors for users in subway station area and level of transportation supply based on the analysis results. The results show that: first, cluster analysis presents that traffic pattern is proved to be different according to land use characteristics(residence, non-residence); second, main transportation variables such as transferring distance, the number of bus stop, the number of short distant bus lines, and the number of bicycle are more supplied in residential area compared to non-residential areas; third, the number of lines, bus dispatching interval, operating time, and distance between subway stations are more supplied in non-residential areas than residential areas. All in all, the results will be useful for providing priority of considerations in case of decision-making on public transportation policy in subway station area.

• Journal of Korean Society on Water Environment
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• v.35 no.6
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• pp.557-566
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• 2019

Paldang is a river reservoir in the Midwest of Korea, which is a drinking water source for the metropolitan area. Since the Paldang Reservoir is shallow, and has a short hydraulic residence time, its water quality is directly impacted by two incoming rivers, the north Han River (NHR) and the south Han River (SHR). The NHR has different seasonal patterns of water temperature from the SHR because the NHR is greatly impacted by the discharge water from upstream dams. The electrical conductivity (EC) and other material concentrations of the SHR are usually higher than those of the NHR because its basin is limestone-based. The difference in water temperature in the two rivers causes density flow, and the distribution of the EC within the reservoir can be an indicator for monitoring density flow. From the vertical gradient of the EC at the dam site, from spring to fall, it was confirmed that the SHR flowed into the upper layer, and the NHR flowed into the lower layer, and vice versa at other times. The relative difference (RD) of the EC between the upper layer and the lower layer at the dam site was used as an indicator for density flow. The RD of the EC showed a very significant correlation with the RD of total organic carbon (r = 0.70, p < 0.001) and the RD of total nitrogen (r = 0.58, p < 0.01). This relationship is based on the assumption that the difference in electrical conductivity and water quality between the SHR and the NHR is constant. However, in many cases this assumption is inconsistent. Thus, further study is needed on more suitable indicators to evaluate the impact of density flow on water quality.

• Journal of architectural history
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• v.24 no.6
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• pp.67-82
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• 2015

With regard to Gung-jung Yeon-hyang(宮中宴享; court banquet), the frequency of banquets that were held at one time beginning Mu-ja J in-jak(戊子進爵; a royal banquet held in 1828) in 1828 (the 28th year of King Sunjo (純祖)'s reign). In proportion to this frequency, there was an increase in the need and importance of Suk-seol-so(熟設所; a kitchen built in temporarily house for court banquet) and Jung-bae-seol-cheong(中排設廳; a temporary place to put offerings) as a space to assist court banquets. Although Suk-seol-so was a temporary but large-scale facility, it was frequently used for long periods. This facility was flexibly established using the variability of Dong-gung(東宮; Palace for Crown Prince) and enhanced the efficiency of censorship and security in conjunction with palace gates and Suk-wi-cheo(宿衛處; guard station, guard room). In addition, it was reused according to the period when the nation and royal family gave finances or banquets. Jung-bae-seol-cheong was established in the place connected to the central space of court banquets and worked as buffer space to resolve the tension on the day of the event. The location where Jung-bae-seol-cheong was established enabled us to confirm the applicability of Bok-do(複道; corridor) connected to Chimjeon(寢殿; royal residence) when holding court banquets. In short, Suk-seol-so and Jung-bae-seol-cheong were auxiliary spaces, but were considered importantly in the palace operation when holding court banquets.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.9
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• pp.709-717
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• 2009

Heat transfer rate is a very important factor for the performance of a steam reformer because a steam reforming reaction is an endothermic reaction. Coaxial cylindrical reactor is the reactor design which can improve the heat transfer rate. Temperature, fuel conversion and heat flux in the coaxial cylindrical steam reformer are studied in this paper using numerical method under various operating conditions. Langmuir-Hinshelwood model and pseudo-homogeneous model are incorporated for the catalytic surface reaction. Dominant chemical reactions are assumed as a Steam Reforming (SR) reaction, a Water-Gas Shift (WGS) reaction, and a Direct Steam Reforming (DSR) reaction. Although coaxial cylindrical steam reformer uses 33% less amount of catalyst than cylindrical steam reformer, its fuel conversion is increased 10 % more and its temperature is also high as about 30 degree. There is no heat transfer limitation near the inlet area at coaxial-type reactor. However, pressure drop of the coaxial cylindrical reactor is 10 times higher than that of cylindrical reactor. Operating parameters of coaxial cylindrical steam reformer are the wall temperature, the inlet temperature, and the Gas Hourly Space Velocity (GHSV). When the wall temperature is high, the temperature and the fuel conversion are increased due to the high heat transfer rate. The fuel conversion rate is increased with the high inlet temperature. However, temperature drop clearly occurs near the inlet area since an endothermic reaction is active due to the high inlet temperature. When GHSV is increased, the fuel conversion is decreased because of the heat transfer limitation and short residence time.