• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.19-32
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• 2007

In Korea, there have been various methods of estimating groundwater recharge which generally can be subdivided into three types: baseflow separation method by means of groundwater recession curve, water budget analysis based on lumped conceptual model in watershed, and water table fluctuation method (WTF) by using the data from groundwater monitoring wells. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, so these methods have various limits to deal with these characteristics. To overcome these limitations, we present a new method of estimating recharge based on water balance components from the SWAT-MODFLOW which is an integrated surface-ground water model. Groundwater levels in the interest area close to the stream have dynamics similar to stream flow, whereas levels further upslope respond to precipitation with a delay. As these behaviours are related to the physical process of recharge, it is needed to account for the time delay in aquifer recharge once the water exits the soil profile to represent these features. In SWAT, a single linear reservoir storage module with an exponential decay weighting function is used to compute the recharge from soil to aquifer on a given day. However, this module has some limitations expressing recharge variation when the delay time is too long and transient recharge trend does not match to the groundwater table time series, the multi-reservoir storage routing module which represents more realistic time delay through vadose zone is newly suggested in this study. In this module, the parameter related to the delay time should be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater table with observed one as well as to compare simulated watershed runoff with observed one. This method is applied to Mihocheon watershed in Korea for the purpose of testing the procedure of proper estimation of spatio-temporal groundwater recharge distribution. As the newly suggested method of estimating recharge has the advantages of effectiveness of watershed model as well as the accuracy of WTF method, the estimated daily recharge rate would be an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers and aquifers.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.15-22
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• 2002

Transportation project appraisal should be precise in order to increase the social welfare and efficiency, and it has been evaluated by only a single criterion analysis such as benefit/cost analysis. However, this method cannot assess some qualitative items, and cannot get a proper solution for the clash of interests among various groups. Therefore, the multi-criteria analysis, which can control these problems, is needed, and then Saaty has developed one of these methods, AHP(Analytic Hierarchy Process) method. In AHP, the project is evaluated through weighted score of the criteria and the alternatives, which is surveyed by a questionnaire of specialists. It is based on some strict suppositions such as reciprocal comparison, homogeneity, expectation, independence relationship between multi-criteria, but supposing that each criterion has independence relation with others is too difficult in two reasons. First, in real situation, there cannot be perfect independence relationship between standards. Second, individuals, even though they are specialists of that area, do not feel the degree of independence relation as same as others. This paper develops a modified AHP method for solving this dependence relationship between multi-criteria. First of all. in this method, the degree of dependence relationship between multi-criteria that the specialist feels is surveyed and included to the weighted score of multi-criteria This study supposes three methods to implement this idea. The first model products the degree of dependence relationship in the first step for calculating the weighted score, and the others adjust the result of weighted score from the basic AHP method to the dependence relationship. One of the second methods distributes the cross weighted score to each standard by constant ratio, and the other splits them using Fuzzy measure such as Bel and Pl. Finally, in order to validate these methods, this paper applies them to evaluate the alternatives which can control public resentments against Korean rail path in a city area.

• The Korean Journal of Archival Studies
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• no.3
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• pp.91-113
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• 2001

History always be re-interpreted as the time flows. 'The Sillok', Which was registered in Memory of World of UNESCO in 1997, is comprehensive documents of the Chosun Dynasty, which had been compiled after kings' death, The Sillok encompasses 473 years of the reign in their 848 volumes(1,893 chapters). It was a history itself and has been main source in studying Korean history. Due to the rise of studies on the Sillok, time has come to explore the nature of the Sillok and to criticize the text, which would be called 'The Sillok-Study'. In this context, this paper examined three concepts that categorize the nature of the Sillok as historical materials ;Is it book or record?; The Sillok in register system in pre-modern society; And the Sillok as the National Archives. Korean historians, including myself, haven't yet examined the question whether the Sillok is the Book or Record in terms of archival science. At first, I regarded it as history book, and with this presupposition, wrote several papers on the characteristics of the Sillok. However, I recognized that the Sillok are close to record rather that history book as I examined the definition of glossary of librarian study, OED (Oxford English Dictionary) and Encyclopedia of Britannica, etc. Definitely, the Sillok was neither compiled and published to be read and sold publicly, nor meant to the works of literature or scholarship. one may say that the court-historians wrote comments on the facts and therefore it was just scholarly work. However, because the court-historians produced their comments on their own businesses, the outcome of 'their scholarly works' were also records conceptually, as were daily court-journalists in Rome. Its publication also had a absolutely different meaning from that of modern society. It was a method to preserve the important national records and distributed each edition of them to plural repositories for its safety and security. How can we explain its book-like shape and the procedure of compilation after a kings' death. The answer is as follows ; In pre-modern society, it was a common record-keeping system in the world to register records materials in order to arrange the materials of different sizes and to store them conveniently. And the lack of scientific preservation or conservation skill also encouraged them to register original records. Actually, the court-historians who participated in the compiling process called themselves "registering officers". On the other hand, similar to social hierarchy, there was a hierarchical system of records, and the Sillok was placed at the top of this hierarchy. In conclusion, the Sillok was a kind of registered records in the middle ages and the supreme records in the records-world. In addition to this we can also conceptualize the Sillok as archives. Through the compiling process, the most important and valuable records were selected to be the parts of Sillok. This process corresponds to the modem records appraisal. In the next step, it was preserved in the Four Archives(史庫) which located at remote site as archives and only accessible by the descendents in the future, who might be the people of the next dynasty. And nobody could access or read the documents at that time except the authorized court-historians who were archivists of the Chosun Dynasty. From this perspective, I conclude that Sillok was the supreme confidential archives in the register system. I work for the Government Archives as a historian and archivist. Whenever I entered the exhibition hall of the Government Archives and Records Service(GARS) and saw the replica of the Archives of Taebeak Mountain built during Chosun period, I always asked to myself a question whether the Sillok can be a symbol of the archival tradition of Korea and the GARS. Now, I can say, 'Yes!' definitely.

• Communications of Mathematical Education
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• v.37 no.2
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• pp.233-256
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• 2023

This study conducted foundational research to derive ways to use ChatGPT in mathematics education by analyzing ChatGPT's responses to questions from the National Assessment of Educational Achievement (NAEA) and the College Scholastic Ability Test (CSAT). ChatGPT, a generative artificial intelligence model, has gained attention in various fields, and there is a growing demand for its use in education as the number of users rapidly increases. To the best of our knowledge, there are very few reported cases of educational studies utilizing ChatGPT. In this study, we analyzed ChatGPT 3.5 responses to questions from the three-year National Assessment of Educational Achievement and the College Scholastic Ability Test, categorizing them based on the percentage of correct answers, the accuracy of the solution process, and types of errors. The correct answer rates for ChatGPT in the National Assessment of Educational Achievement and the College Scholastic Ability Test questions were 37.1% and 15.97%, respectively. The accuracy of ChatGPT's solution process was calculated as 3.44 for the National Assessment of Educational Achievement and 2.49 for the College Scholastic Ability Test. Errors in solving math problems with ChatGPT were classified into procedural and functional errors. Procedural errors referred to mistakes in connecting expressions to the next step or in calculations, while functional errors were related to how ChatGPT recognized, judged, and outputted text. This analysis suggests that relying solely on the percentage of correct answers should not be the criterion for assessing ChatGPT's mathematical performance, but rather a combination of the accuracy of the solution process and types of errors should be considered.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.46-46
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• 2011

Severe sediment erosion during floods occur disaster and economic losses, but general sediment erosion is basic mechanism to move sediment from upstream to downstream river. In addition, it is important process to change river form. Check dam, which is constructed in mountain stream, play a vital role such as control of sudden debris flow, but it has negative aspects to river ecosystem. Now a day, check dam of open type is an alternative plan to recover river biological diversity and ecosystem through sediment transport while maintaining the function of disaster control. The purpose of this paper is to verify sediment erosion progress of river bottom and bank as first step for river restoration after dam slit by cross-sectional shear stress and critical shear stress. Study area is upstream reach of slit check dam in mountain stream, named Wasada, in Japan. The check dam was slit with two passages in August, 2010. The transects were surveyed for four upstream cross-sections, 7.4 m, 34 m, 86 m, and 150 m distance from dam in October 2010. Sediment size was surveyed at river bottom and bank. Sediment of cobble size was found at the wetted bottom, and small size particles of sand to medium gravel composed river bank. Discharge was $2.5\;m^3/s$ and bottom slope was 0.027 m/m. Excess shear stress (${\tau}_{ex}$) was calculated for hydraulic erosion by subtracting the values of critical shear stress (${\tau}_{c}$) from the value of shear stress (${\tau}$) at river bottom and bank (${\tau}_{ex}=\tau-{\tau}_c$). Shear stress of river bottom (${\tau}_{bottom}$) was calculated using the cross-sectional shear stress, and bank shear stress (${\tau}_{bank}$) was calculated from the method of Flintham and Carling (1988). $${\tau}_{bank}={\tau}^*SF_{bank}((B+P_{bed})/(2^*P_{bank}))$$ where $SF_{bank}=1.77(P_{bed}/p_{bank}+1.5)^{-1.4}$, B is the water surface width, $P_{bed}$ and $P_{bank}$ are wetted parameter of the bed and bank. Estimated values for ${\tau}_{bottom}$ for a flow of $2.5\;m^3/s$ were lower as 25.0 (7.5 m cross-section), 25.7 (34 m), 21.3 (86 m) and 19.8 (150 m), in N/$m^2$, than critical shear stress (${\tau}_c=62.1\;N/m^2$) with cobble of 64 mm. The values were insufficient to erode cobble sediment. In contrast, even if the values of ${\tau}_{bank}$ were lower than the values for ${\tau}_{bottom}$ as 18.7 (7.5 m), 19.3 (34 m), 16.1 (86 m) and 14.7 (150 m), in N/$m^2$, excess shear stresses were calculated at the three cross-sections of 7.5 m, 34 m, and 86 m distances compare with ${\tau}_c$ is 15.5 N/$m^2$ of 16mm gravel. Bank shear stresses were sufficient for erosion of the medium gravel to sand. Therefore there is potential to erode lateral bank than downward erosion in a flow of $2.5\;m^3/s$. Undercutting of the wetted bank can causes bank scour or collapse, therefore this channel has potential to become wider at the same time. This research is about a potential of sediment erosion, and the result could not verify with real data. Therefore it need next step for verification. In addition an erosion mechanism for river restoration is not simple because discharge distribution is variable by snow-melting or rainy season, and a function for disaster control will recover by big precipitation event. Therefore it needs to consider the relationship between continuous discharge change and sediment erosion.

• Journal of Intelligence and Information Systems
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• v.27 no.3
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• pp.199-230
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• 2021

Innovative new products and services are being launched through the convergence between heterogeneous industries, and social interest and investment in convergence industries such as AI, big data-based future cars, and robots are continuously increasing. However, in the process of commercialization of convergence new products and services, there are many cases where they do not conform to the existing regulatory and legal system, which causes many difficulties in companies launching their products and services into the market. In response to these industrial changes, the current government is promoting the improvement of existing regulatory mechanisms applied to the relevant industry along with the expansion of investment in new industries. This study, in these convergence industry trends, aimed to analysis the existing regulatory system that is an obstacle to market entry of innovative new products and services in order to preemptively predict regulatory issues that will arise in emerging industries. In addition, it was intended to establish a regulatory impact analysis system to evaluate adequacy and prepare improvement measures. The flow of this study is divided into three parts. In the first part, previous studies on regulatory impact analysis and evaluation systems are investigated. This was used as basic data for the development direction of the regulatory impact framework, indicators and items. In the second regulatory impact analysis framework development part, indicators and items are developed based on the previously investigated data, and these are applied to each stage of the framework. In the last part, a case study was presented to solve the regulatory issues faced by actual companies by applying the developed regulatory impact analysis framework. The case study included the autonomous/electric vehicle industry and the Internet of Things (IoT) industry, because it is one of the emerging industries that the Korean government is most interested in recently, and is judged to be most relevant to the realization of an intelligent information society. Specifically, the regulatory impact analysis framework proposed in this study consists of a total of five steps. The first step is to identify the industrial size of the target products and services, related policies, and regulatory issues. In the second stage, regulatory issues are discovered through review of regulatory improvement items for each stage of commercialization (planning, production, commercialization). In the next step, factors related to regulatory compliance costs are derived and costs incurred for existing regulatory compliance are calculated. In the fourth stage, an alternative is prepared by gathering opinions of the relevant industry and experts in the field, and the necessity, validity, and adequacy of the alternative are reviewed. Finally, in the final stage, the adopted alternatives are formulated so that they can be applied to the legislation, and the alternatives are reviewed by legal experts. The implications of this study are summarized as follows. From a theoretical point of view, it is meaningful in that it clearly presents a series of procedures for regulatory impact analysis as a framework. Although previous studies mainly discussed the importance and necessity of regulatory impact analysis, this study presented a systematic framework in consideration of the various factors required for regulatory impact analysis suggested by prior studies. From a practical point of view, this study has significance in that it was applied to actual regulatory issues based on the regulatory impact analysis framework proposed above. The results of this study show that proposals related to regulatory issues were submitted to government departments and finally the current law was revised, suggesting that the framework proposed in this study can be an effective way to resolve regulatory issues. It is expected that the regulatory impact analysis framework proposed in this study will be a meaningful guideline for technology policy researchers and policy makers in the future.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.658-672
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• 2022

The unique teaching and learning difficulties of speed-related units in elementary school science are mainly due to the student's lack of mathematical thinking ability and procedural knowledge on speed measurement, and curriculums and textbooks must be constructed with these in mind. To identify the implications of composing a new science curriculum and relevant textbooks, this study reviewed the structure and contents of the speed-related units of three curriculums from the 2007 revised curriculum to the 2015 revised curriculum and the resulting textbooks and examined their relevance in light of the literature. Results showed that the current content carries the risk of making students calculate only the speed of an object through a mechanical algorithm by memorization rather than grasp the multifaceted relation between traveled distance, duration time, and speed. Findings also highlighted the need to reorganize the curriculum and textbooks to offer students the opportunity to learn the meaning of speed step-by-step by visualizing materials such as double number lines and dealing with simple numbers that are easy to calculate and understand intuitively. In addition, this paper discussed the urgency of improving inquiry performance such as process skills by observing and measuring an actual object's movement, displaying it as a graph, and interpreting it rather than conducting data interpretation through investigation. Lastly, although the current curriculum and textbooks emphasize the connection with daily life in their application aspects, they also deal with dynamics-related content somewhat differently from kinematics, which is the main learning content of the unit. Hence, it is necessary to reorganize the contents focusing on cases related to speed so that students can grasp the concept of speed and use it in their everyday lives. With regard to the new curriculum and textbooks, this study proposes that students be provided the opportunity to systematically and deeply study core topics rather than exclude content that is difficult to learn and challenging to teach so that students realize the value of science and enjoy learning it.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.3
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• pp.60-68
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• 2009

This work proposes a 10b 200MS/s 65nm CMOS ADC for high-definition video systems such as HDTV requiring high resolution and fast operating speed simultaneously. The proposed ADC employs a four-step pipeline architecture to minimize power consumption and chip area. The input SHA based on four capacitors reduces the output signal range from $1.4V_{p-p}$ to $1.0V_{p-p}$ considering high input signal levels at a low supply voltage of 1.2V. The proposed three-stage amplifiers in the input SHA and MDAC1 overcome the low output resistance problem as commonly observed in a 65nm CMOS process. The proposed multipath frequency-compensation technique enables the conventional RNMC based three-stage amplifiers to achieve a stable operation at a high sampling rate of 200MS/s. The conventional switched-bias power-reduction technique in the sub-ranging flash ADCs further reduces power consumption while the reference generator integrated on chip with optional off-chip reference voltages allows versatile system a locations. The prototype ADC in a 65nm CMOS technology demonstrates a measured DNL and INL within 0.19LSB and 0.61LSB, respectively. The ADC shows a maximum SNDR of 54.BdB and 52.4dB and a maximum SFDR of 72.9dB and 64.8dB at 150MS/S and 200MS/s, respectively. The proposed ADC occupies an active die area of $0.76mm^2$ and consumes 75.6mW at a 1.2V supply voltage.

• (The)Study of the Eastern Classic
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• no.72
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• pp.35-66
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• 2018

This thesis has examined Jo Guimyeong's observation method and rhetoric of style of writing style. He tried to look at the world differently through observation and expressed relationship with the world through the style of comic. $J{\breve{o}}nggwan$ is a new way of looking at subjects and objects. It trust the senses and thoughts of the subject. So It is to clarify the circumstances and logic of the world from one's own point of view. In this case, it collides with the common thinking of the day. He put the reason and the action standard in the "taste" and the "mind". This means three things. First, he is proud that his reasons and actions are no different from those of a saint. Second, an individual is an independent being with different emotions and thoughts. Third, based on this, his works of literature have their own value. These reasons and actions were incarnated through '$J{\breve{o}}nggwan$(靜觀)'s observation methods. What he gained from the three stages of $J{\breve{o}}nggwan$(靜觀)' is the 'great mind'. The first step is self-reflection. It is the process of objectifying oneself. The second target is the appearance of things. It's about looking at everything equally, whether it's precious or vulgar. The third object of observation is a harmonic. He is joining the movement of the harmonizers. Therefore, one's own reasons, actions, and works of literature share the same meaning as those of a harmonizer. He said that the description can change according to his own knowledge. It means that you can fit the situation. A typical example was the analysis of 'Sung Bo hyung hwasangchan'<成甫兄畵像贊>. He described Park Moon-soo's life as the lives of officials through comic. Through this, He criticized Park Moon-soo's natural nature of the academic world. but the situation in which he can't escape from bureaucratic life by inducing laughter. This style of writing is one of the most representative features which was written by Jo Guimyeong writer.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.3
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• pp.183-200
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• 2022

This study is a study on the effect of a healing experience program on satisfaction in the field of healing agriculture. In the development of a rural experience program, what factors constituting the healing experience program affect satisfaction, and how much time and participation cost affect the satisfaction of the healing experience program from the marketing point of view of the healing experience program. I want to analyze By researching the effect of experience cost and experience time on satisfaction of the healing experience program, I would like to suggest the development direction of the healing experience program. To this end, by empirically analyzing the effect of a healing experience program using experience cost and experience time as parameters on satisfaction, we present a theoretical basis for priority considerations when developing a rural experience program. There are entertainment experience, educational experience, deviant experience, and aesthetic experience as sub-factors of the experience program, experience time and experience cost as parameters, and satisfaction as a dependent variable. In addition, the reliability of the research results was secured by setting the demographic variables of the survey subjects as control variables. The empirical analysis was conducted on 314 valid questionnaires from the unspecified majority who were interested in or aware of the healing experience program. SPSS v22.0 was used, and to test the mediating effect, the three-step verification method of Baron & Kenny(1986) and the SPSS PROCESS Macro Model No. of Andrew F. Hayes(2018). 4 The reliability of the mediating effect was secured by applying the verification method and comparing the analysis resul. As a result of the study, it was found that educational experience (𝛽=.134, t=1.759*) had a positive (+) effect on experience cost, and aesthetic experience (𝛽=.144 t=1.684*) had a positive (+) effect on experience time. +) was found to have an effect. Also, educational experience (𝛽=.239, t=4.112***) was found to have a positive (+) effect on satisfaction, and aesthetic experience (𝛽=.330 t=4.921***) had a positive effect on satisfaction. It has been shown to have a (+) effect. Experience time was found to have a negative (-) inconsistent mediating effect between aesthetic experience and satisfaction. That is, it is the total effect (𝛽=.330 t=4.921***), and the direct effect (𝛽=.349 t=5.241***) increased by 𝛽=.019 compared to the total effect when the experience time was input, while the indirect effect (𝛽=-.019), which was shown to exert a negative (-) mediating effect.