• The Journal of Korean Philosophical History
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• no.57
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• pp.127-150
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• 2018

Although Wangfu's Tian-Ren relations theory could not be free from the influence of the religious understanding of the Yinyangwuxing theory, which was prevalent in the times of two Hans, due to the limitations of the times, it refers to human status and capabilities here and there of the "Qianfulun" and traces of attempts to enhance humans' ability to preside and attempts to dilute the powers of Tian(heaven) and God can be found. In addition, the fact that the theory shifted the focus of the administration and politics of the state from Tian(heaven) to the people can be also said to be highly worthwhile. Of course, when seen from philosophical, political, social, and economic perspectives, Wangfu's primary concern can be said to have been the stabilization of people's livelihood. The influence and contribution of Wangfu's ?Qianfulun? as such on the aspects of political and philosophical thoughts in the society at the time can be said to be comparable to those of Wangchong. Although there are the limitations of the situations of the times faced by Wangfu that made him unable to surpass the standardized paradigm of the Tian-Ren response theory, when seen from other perspectives, the fact that he severely criticized the confused social conditions at that time unlike other intellectuals in the confused situations at the end of the East Han Dynasty period can be said to be worth affirmation. The fact that Wangfu, who tried to work on the basis, the stabilization of the people's livelihood, concentrated most of his energy on overcoming the situation of national internal and external troubles such as breaking down the bad customs of operating the national administration by religious notions such as natural calamity or superstition instead of trying to solve the problems of the times from the academic and ideological aspects as with Wangchong can be also said to be valuable in itself. In addition, Wangfu naturally became to take the lead in breaking down deeply superstitious notions such as the Yinyangwuxing theory and the Chanwei theory while he was conducting studies on how practical problems could be overcome facing the situations in the turbulent period.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1234-1268
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• 2004

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2002 and 2003 has been carried out. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment/design. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation in diverse facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat transfer, humidity was also interesting to promote comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing research topics. Well developed CFD technologies were widely applied for analysis and design of various facilities and their systems. (2) Heat transfer characteristics of enhanced finned tube heat exchangers and heat sinks were extensively investigated. Experimental studies on the boiling heat transfer, vortex generators, fluidized bed heat exchangers, and frosting and defrosting characteristics were also conducted. In addition, the numerical simulations on various heat exchangers were performed and reported to show heat transfer characteristics and performance of the heat exchanger. (3) A review of the recent studies shows that the performance analysis of heat pump have been made by various simulations and experiments. Progresses have been made specifically on the multi-type heat pump systems and other heat pump systems in which exhaust energy is utilized. The performance characteristics of heat pipe have been studied numerically and experimentally, which proves the validity of the developed simulation programs. The effect of various factors on the heat pipe performance has also been examined. Studies of the ice storage system have been focused on the operational characteristics of the system and on the basics of thermal storage materials. Researches into the phase change have been carried out steadily. Several papers deal with the cycle analysis of a few thermodynamic systems which are very useful in the field of air-conditioning and refrigeration. (4) Recent studies on refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement when new alternative refrigerants are applied. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and new alternative refrigerants including natural refrigerants. Efficiency of various compressors and performance of new expansion devices are also dealt with for better design of refrigeration/air conditioning system. In addition to the studies related with thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out. It should be noted that the researches on two-phase flow are constantly carried out. (5) A review of the recent studies on absorption refrigeration system indicates that heat and mass transfer enhancement is the key factor in improving the system performance. Various experiments have been carried out and diverse simulation models have been presented. Study on the small scale absorption refrigeration system draws a new attention. Cooling tower was also the research object in the respect of enhancement its efficiency, and performance analysis and optimization was carried out. (6) Based on a review of recent studies on indoor thermal environment and building service systems, it is noticed that research issues have mainly focused on several innovative systems such as personal environmental modules, air-barrier type perimeterless system with UFAC, radiant floor cooling system, etc. New approaches are highlighted for improving indoor environmental conditions and minimizing energy consumption, various activities of building energy management and cost-benefit analysis for economic evaluation.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.199-208
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• 2021

Environmental DNA (eDNA) metabarcoding is effective method with high detection sensitivity for evaluating fish biodiversity and detecting endangered fish from natural water samples. We compared the richness of operational taxonomic units(OTUs) and composition of freshwater fishes according to filters(cellulose nitrate filter vs. glass fiber filter), extraction kits(DNeasy2^® Blood & Tissue Kit vs. DNeasy2^® PowerWater Kit), primer sets (12S rDNA vs. 16S rDNA), and PCR methods (conventional PCR vs. touchdown PCR) to determine the optimal conditions for metabarcoding analysis of Korean freshwater fish. The glass fiber filter and DNeasy2^® Blood & Tissue Kit combination showed the highest number of freshwater fish OTUs in both 12S and 16S rDNA. Among the four types, the primer sets only showed statistically significant difference in the average number of OTUs in class Actinopterygii (non-parametric Wilcoxon signed ranks test, p=0.005). However, there was no difference in the average number of OTUs in freshwater fish. The species composition also showed significant difference according to primer sets (PERMANOVA, Pseudo-F=6.9489, p=0.006), but no differences were observed in the other three types. The non-metric multidimensional scaling (NMDS) results revealed that species composition clustered together according to primer sets based on similarity of 65%; 16S rDNA primer set was mainly attributed to endangered species such as Microphysogobio koreensis and Pseudogobio brevicorpus. In contrast, the 12S rDNA primer set was mainly attributed to common species such as Zacco platypus and Coreoperca herzi. This study provides essential information on species diversity analysis using metabarcoding for environmental water samples obtained from rivers in Korea.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1657-1667
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• 2021

Anthropogenic activities and natural processes have been causes of land subsidence which is sudden sinking or gradual settlement of the earth's solid surface. Mexico City, the capital of Mexico, is one of the most severe land subsidence areas which are resulted from excessive groundwater extraction. Because groundwater is the primary water resource occupies almost 70% of total water usage in the city. Traditional terrestrial observations like the Global Navigation Satellite System (GNSS) or leveling survey have been preferred to measure land subsidence accurately. Although the GNSS observations have highly accurate information of the surfaces' displacement with a very high temporal resolution, it has often been limited due to its sparse spatial resolution and highly time-consuming and high cost. However, space-based synthetic aperture radar (SAR) interferometry has been widely used as a powerful tool to monitor surfaces' displacement with high spatial resolution and high accuracy from mm to cm-scale, regardless of day-or-night and weather conditions. In this paper, advanced interferometric approaches have been applied to get a time-series of land subsidence of Mexico City using four-year-long twenty ALOS PALSAR L-band observations acquired from Feb-11, 2007 to Feb-22, 2011. We utilized persistent scatterer interferometry (PSI) and small baseline subset (SBAS) techniques to suppress atmospheric artifacts and topography errors. The results show that the maximum subsidence rates of the PSI and SBAS method were -29.5 cm/year and -27.0 cm/year, respectively. In addition, we discuss the different subsidence rates where the study area is discriminated into three districts according to distinctive geotechnical characteristics. The significant subsidence rate occurred in the lacustrine sediments with higher compressibility than harder bedrock.

• The Korean Journal of Archival Studies
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• no.12
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• pp.179-235
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• 2005

In this article, the task of evaluating the official documents that were created and issued by the Joseon Governor General office during the Japanese occupation period, with new perspectives based upon the Macro-Appraisal approaches developed by the Canadian scholars and personnel, will be attempted. Recently, the Canadian people and the authorities have been showing a tendency of evaluating the meaning and importance of a particular document with perspectives considering the historical situation and background conditions that gave birth to that document to be a more important factor, even than considering the quality and condition of that very document. Such approach requires the archivists to determine whether they should preserve a certain document or not based upon the meaning, functions and status of the entity that produced the document or the meaning of the documentation practice itself, rather than the actual document. With regard to the task of evaluating the official documents created and issued by the Joseon Governor General office and involved the city plans devised by the office back then, this author established total of 4 primary tasks that would prove crucial in the process of determining whether or not a particular theme, or event, or an ideology should be selected and documents involving those themes, events and ideologies should be preserved as important sources of information regarding the Korean history of the Japanese occupation period. Those four tasks are as follow: First, the archivists should study the current and past trends of historical researches. The archivists, who are usually not in the position of having comprehensive access to historical details, must consult the historians' studies and also the trends mirrored in such studies, in their efforts of selecting important historical events and themes. Second, the archivists should determine the level of importance of the officials who worked inside the Joseon Governor General office as they were the entities that produced the very documents. It is only natural to assume that the level of importance of a particular document must have been determined by the level of importance(in terms of official functions) of the official who authorized the document and ordered it to be released. Third, the archivists should be made well aware of the inner structure and official functions of the Joseon Governor General office, so that they can have more appropriate analyses. Fourth, in order to collect historically important documents that involved the Koreans(the Joseon people), the archivists should analyze not only the functions of the Joseon Governor General office in general but also certain areas of the Office's business in which the Japanese officials and the Koreans would have interacted with each other. The act of analyzing the documents only based upon their respective levels of apparent importance might lead the archivists to miss certain documents that reflected the Koreans' situation or were related to the general interest of the Korean people. This kind of evaluation should provide data that are required in appraising how well the Joseon Governor General office's function of devising city plans were documented back then, and how well they are preserved today, utilizing a comparative study involving the Joseon Governor General office's own evaluations of its documentations and the current status of documents that are in custody of the National Archive. The task would also end up proposing a specialized strategy of collecting data and documents that is direly needed in establishing a well-designed comprehensive archives. We should establish a plan regarding certain documents that were documented by the Joseon Governor General office but do not remain today, and devise a task model for the job of primary collecting that would take place in the future.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.216-227
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• 2019

The purpose of this study is to propose the rational mountain stream management strategy considering the natural conditions and social needs of the Republic of Korea. We reviewed domestic and overseas studies related to mountain streams, identified the study areas by text mining and co-word analysis using the VOSviewer program, and then analyzed the spatial and temporal study trends and topics of each study area. The results showed that domestic studies on mountain streams are still in an initial stage compared to overseas studies. Overseas studies on mountain streams can be classified into four groups: (i) habitat and species composition of fish and invertebrates, (ii) hydrological phenomena and nutrient migration, (iii) transport of sediment and organic materials and the relevant morphological changes by runoff flows, and (iv) plant species composition in mountain streams. Of these study subjects, domestic studies belonging to the (i) group mainly focused on macroinvertebrates while domestic studies belonging to the (iii) group regarded transport of sediment and organic materials as not the ecological disturbance but the source of sediment-related disasters. We then analyzed the rate of each research group to all papers by period and country. The results showed that the overseas studies belonging to (iii) and (iv) groups have increased with time, and the increase was mostly due to the studies in the United States, Brazil, Canada, and China. On the other hand, domestic studies belonging to (i) and (iii) groups increased somewhat with time, but there was a slight lack of correlation between the two subjects. Therefore, the hybridity studies to complement the shortage is necessary for the future.

• Korean Journal of Heritage: History & Science
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• v.51 no.1
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• pp.32-47
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• 2018

The purpose of this study is to examine the vegetation maintenance project that was conducted as a part of the Official Development Assistance (ODA) project for the historic site of Angkor, to analyze the aspects and characteristics of the project, and to derive implications for the establishment of future policies and strategies. First, the key words used in the vegetation maintenance project at the historic site of Angkor do not only refer to the concept of plants (and more specifically to 'trees') but also to the concept of heritage. In other words, the concept of heritage is not limited to architectural structures but is also intended to mean the vegetation and surroundings that form the historic site. Second, the expansion of the value of vegetation has contributed to the establishment of the basic principles of conservation based on the 'coexistence' between architectural structures and vegetation; here, vegetation has come to be recognized as an 'essential' element in the conservation of historic sites. Third, the range of vegetation maintenance has expanded from each tree to the surroundings of the temples, and vegetation maintenance came to adopt 'integrative' and 'active' directions to improve not only the growth environment of the vegetation but also the viewing environment experienced by visitors. This change means that it is necessary for the historic site maintenance project to comprehensively deal with the temples and their surrounding areas. Fourth, for the effective performance of the ODA project, the role of the International Coordinating Committee for the Safeguarding and Development of the Historic Site of Angkor (ICC-Angkor), under the influence of UNESCO, was expanded from an examination of the problems with the existing projects to a search for solutions to technical consultation and supervision. This implies that, in order to perform the ODA project in a way that is appropriate to the local conditions, it is important to reach gradual and phased agreements with ICC-Angkor.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.2
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• pp.82-96
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• 2019

This study evaluated the status of watershed health in Geum River Basin by SWAT (Soil and Water Assessment Tool) hydrology and water quality. The watershed healthiness from watershed hydrology and stream water quality was calculated using multivariate normal distribution from 0(poor) to 1(good). Before evaluation of watershed healthiness, the SWAT calibration for 11 years(2005~2015) of streamflow(Q) at 5 locations with 0.50~0.77 average Nash-Sutcliffe model efficiency and suspended solid (SS), total nitrogen(T-N), and total phosphorus(T-P) at 3 locations with 0.67~0.94, 0.59~0.79, and 0.61~0.79 determination coefficient($R^2$) respectively. For 24 years (1985~2008) the spatiotemporal change of watershed healthiness was analyzed with calibarted SWAT and 5 land use data of 1985, 1990, 1995, 2000, and 2008. The 2008 SWAT results showed that the surface runoff increased by 40.6%, soil moisture and baseflow decreased by 6.8% and 3.0% respectively compared to 1985 reference year. The stream water quality of SS, T-N, and T-P increased by 29.2%, 9.3%, and 16.7% respectively by land development and agricultural activity. Based on the 1985 year land use condition. the 2008 watershed healthiness of hydrology and stream water quality decreased from 1 to 0.94 and 0.69 respectively. The results of this study be able to detect changes in watershed environment due to human activity compared to past natural conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.144-151
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• 2019

The establishment rate of foxtail millet seeds is greatly affected by soil environment conditions. To enhance germination viability and stable production of foxtail millet seeds, it is important to select seeds with a high density. Therefore, this study tested the selection of high-quality seeds using salt solution (specific gravity: 1.000, 1.005, 1.010, 1.015, 1.020, 1.025, 1.030, 1.035, and $1.040g\;L^{-1}$) and investigated their germination rates, percentages of emergence, and seeding quality. In this study, three varieties were tested: 'Hwanggeum', 'Samdachal', and 'Kyeongkwan1'. The thousand seed weight of all three varieties increased proportionally with specific gravity. The highest thousand seed weight was observed at the selection with $1.040g\;L^{-1}$ specific gravity, which also had the highest germination rate of 88.3%, 86.7%, and 90.6%, for 'Hwanggeum'; 'Samdachal'; and 'Kyeongkwan1', respectively. The results of seeding quality indicated that higher the specific gravity during selection, the higher were the values of plant growth (plant height, leaf length, stem diameter, root length, root weight, and stem weight). All the three varieties were found to be longer or heavier for seeds selected at the specific gravity of $1.040g\;L^{-1}$. The packing germination viability investigation found that higher the specific gravity for selection of seeds, the higher was the percentage of emergence (PE) and the emergence rate index (ERI). The PE was the highest for seeds selected at $1.040g\;L^{-1}$ specific gravity (85.3, 83.0, and 87.0%), and ERI was also as high as $2.82d^{-1}\;m^{-1}$ or more at $1.040g\;L^{-1}$. Selection of seeds with salt solution resulted in high germination viability of foxtail millet. Therefore, sowing seeds selected at $1.040g\;L^{-1}$ specific gravity is expected to help substantially in increased productivity.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.2
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• pp.85-96
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• 2019

Solar radiation is an important variable for estimation of energy balance and water cycle in natural and agricultural ecosystems. A deep neural network (DNN) model has been developed in order to estimate the daily global solar radiation. Temperature and precipitation, which would have wider availability from weather stations than other variables such as sunshine duration, were used as inputs to the DNN model. Five-fold cross-validation was applied to train and test the DNN models. Meteorological data at 15 weather stations were collected for a long term period, e.g., > 30 years in Korea. The DNN model obtained from the cross-validation had relatively small value of RMSE ($3.75MJ\;m^{-2}\;d^{-1}$) for estimates of the daily solar radiation at the weather station in Suwon. The DNN model explained about 68% of variation in observed solar radiation at the Suwon weather station. It was found that the measurements of solar radiation in 1985 and 1998 were considerably low for a small period of time compared with sunshine duration. This suggested that assessment of the quality for the observation data for solar radiation would be needed in further studies. When data for those years were excluded from the data analysis, the DNN model had slightly greater degree of agreement statistics. For example, the values of $R^2$ and RMSE were 0.72 and $3.55MJ\;m^{-2}\;d^{-1}$, respectively. Our results indicate that a DNN would be useful for the development a solar radiation estimation model using temperature and precipitation, which are usually available for downscaled scenario data for future climate conditions. Thus, such a DNN model would be useful for the impact assessment of climate change on crop production where solar radiation is used as a required input variable to a crop model.