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Evaluation of water drainage according to hydraulic properties of filling material of sand dam in Mullori, Chuncheon (춘천 물로리 지역 샌드댐 채움재 수리특성에 따른 배수량 평가)

  • Chung, Il-Moon;Lee, Jeongwoo;Kim, Min-Gyu;Kim, Il-Hwan
    • Journal of Korea Water Resources Association
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    • v.55 no.11
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    • pp.923-929
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    • 2022
  • The Chuncheon Mullori area is an underprivileged area of water welfare where local water supply is not supplied, and it is supplying water to the villages with small water supply facilities using lateral flow and groundwater as water sources. This is an area with poor water supply conditions, such as relying on water trucks due to water shortages during the recent severe drought. Therefore, in order to solve the problem of water shortage during drought and to prepare for the increasing water demand, a sand dam was installed along the valley, and this facility has been operating since May 2022. In this study, repeated simulations were performed according to the hydraulic conductivity of the filler material and the storage coefficient value for the inflow condition for about two years from mid-March 2020 to mid-March 2022. For each case, the amount of discharge through the perforated drain pipe was calculated. Overall, as the hydraulic conductivity increased, the amount of discharge and its ratio increased. However, when the hydraulic conductivity of the second floor was relatively low, the amount of discharge increased and then decreased as the hydraulic conductivity of the third floor increased. This is considered to be due to the fact that the water level was kept low due to the rapid drainage compared to the net inflow into the third floor because the water permeability of the third floor and the drainage coefficient of the drain pipe were large. As a result of simulating the flow of the open channel in the upper part of the sand dam as a hypothetical groundwater layer with very high hydraulic conductivity, the decrease in discharge rate was slower than the increase in the hydraulic conductivity of the hypothetical layer, but it was clearly shown that the discharge volume decreased relatively as the hydraulic conductivity of the virtual layer increased.

The Study of the Identity of Christian Educators in Autobiographical Writing of Christian Educational Books: Focusing on the books of Palmer, Harris, and Moore. (기독교교육학 저서의 자전적 글쓰기에 나타난 기독교교육학자의 정체성 연구: 파머, 해리스, 무어를 중심으로)

  • Kim, Eun Joo
    • Journal of Christian Education in Korea
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    • v.68
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    • pp.345-374
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    • 2021
  • This study is a paper which studies the fact that autobiographical writing in Christian educational books is an important channel for studying the identity of Christian educators. The identity of Christian educators is the background and foundation of the study of Christian education theory. It was found through research that the scholar's identity is more evident in autobiographical writing from a first-person perspective experienced by the author than in argumentative writing with objective and cognitive limitations. This study examined the concept and characteristics of autobiographical writing research, the relationship of autobiographical writing research and self-identity, the relationship between autobiographical writing and Christian education, and discovered autobiographical writing in Christian educational scholars' books. Through the autobiographical writing of Maria Harris' Teaching and Religious Imagination, Parker Palmer's The Courage to Teach, and Elizabeth Moore's Teaching as a Sacrament Act, we studied that the identity of Christian educators can meet, transform, and expand learners' identity as well. Through research, it has been confirmed that autobiographical writing takes the form of a story, but as a story distinct from the story, it becomes a place where the authors' identity and readers' identity can meet, wrestle and expand. Autobiographical writing has a relationship with story and self-identity. These characteristics are also linked to Christian educational goals that focus on the formation and transformation of self-identity. The autobiographical writing in Harris, Palmer, and Moore's writings shows the identity of a teacher, including scholars' theological perspectives and views on education. As the writing of Christian education books so far has become argumentative and objective writing, readers has felt a sense of disparity and disconnection. If autobiographical writing becomes educational books' style, it can invite readers to empathize with who the author is. Christian education will experience more fundamental changes with autobiographical writing.

Spatial Distribution and Successional Changes of Riparian Vegetation on Sandbars Exposed after Watergate-Opening of Weirs in the Geumgang River, South Korea (보 개방 후 노출된 금강 모래톱에서 하천 식생의 공간 분포와 천이)

  • Lee, Cheolho;Kim, Hwirae;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.9 no.3
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    • pp.194-205
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    • 2022
  • Sandbars formed by sediment transportation and sedimentation are some of the most important habitats for specific wildlife and they provide an aesthetic landscape in streams. The purpose of this study was to understand the successional process of the colonization and development of early vegetation over time on sandbars exposed by the opening of a gate at a downstream weir. We selected the following four study sites in the Geumgang River, South Korea: three weir-upstream sites with different gate-opening times and a control site that was not affected by weir operation. Changes in the structural characteristics and spatial distribution of the riparian vegetation on the sandbars exposed after opening the gate at the weir were surveyed according to the different exposure periods of the sandbars at the study sites. The newly formed sandbars accounted for more than 33% of the area of the existing floodplain in the three weir-upstream sites of the Geumgang River after opening the gate at the weir. Nine main plant communities were distributed on the exposed sandbars. These communities were classified as annual mesophytic, perennial hydrophytic, perennial hygrophytic, subtree, and tree vegetation based on their species traits. As the duration of exposure of the sandbar increased, the area of the bare sandbar and the annual herbaceous and perennial hydrophytic communities decreased, and the areas occupied by perennial hygrophytic, subtree, and tree communities increased. Changes in vegetation on the sandbar were classified into three types of succession according to the condition of the aquatic habitat before the gate-opening and the degree of physical disturbance caused by the water flow after the gate-opening. The types of succession were: 1) succession starting from hydrophytes in the lentic aquatic zone, 2) succession starting from annual herbaceous hygrophytes in the lotic aquatic zone, and 3) willow-dominated succession in the disturbed channel side. Our results suggested that the dynamics of successional changes in vegetation should be considered during weir operation to ecologically manage the habitats and landscape of the fluvial landforms, including sandbars in streams.

Evaluation of Spectral Band Adjustment Factor Applicability for Near Infrared Channel of Sentinel-2A Using Landsat-8 (Landsat-8을 활용한 Sentinel-2A Near Infrared 채널의 Spectral Band Adjustment Factor 적용성 평가)

  • Nayeon Kim;Noh-hun Seong;Daeseong Jung;Suyoung Sim;Jongho Woo;Sungwon Choi;Sungwoo Park;Kyung-Soo Han
    • Korean Journal of Remote Sensing
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    • v.39 no.3
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    • pp.363-370
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    • 2023
  • Various earth observation satellites need to provide accurate and high-quality data after launch. To maintain and enhance the quality of satellite data, it is crucial to employ a cross-calibration process that accounts for differences in sensor characteristics, such as the spectral band adjustment factor (SBAF). In this study, we utilized Landsat-8 and Sentinel-2A satellite imagery collected from desert sites in Libya4, Algeria3, and Mauritania2 among pseudo-invariant calibration sites to calculate and apply SBAF, thereby compensating the uncertainties arising from variations in bandwidths. We quantitatively compared the reflectance differences based on the similarity of bandwidths, including Blue, Green, Red, and both the near-infrared (NIR) narrow, and NIR bands of Sentinel-2A. Following the application of SBAF, significant results with reflectance differences of approximately 1% or less were observed for all bands except NIR. In the case of the Sentinel-2A NIR band, it exhibited a significantly larger bandwidth difference compared to the NIR narrow band. However, after applying SBAF, the reflectance difference fell within the acceptable error range (5%) of 1-2%. It indicates that SBAF can be applied even when there is a substantial difference in the bandwidths of the two sensors, particularly in situations where satellite utilization is limited. Therefore, it was determined that SBAF could be applied even when the bandwidth difference between the two sensors is large in a situation where satellite utilization is limited. It is expected to be helpful in research utilizing the quality and continuity of satellite data.

Householder's Working Type and Household Saving: A Perspective of the Precautionary Saving Behavior Theory (가구주 근로유형과 가계저축: 예비적 저축행동 이론의 관점)

  • Shim, Young
    • Journal of Consumption Culture
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    • v.15 no.1
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    • pp.93-118
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    • 2012
  • The purpose of this study was to examine the effect of a householder's working type on household saving from the perspective of precautionary saving behavior theory and the determinants of household saving by householder's working type. The data for this study was from the 2009 year of the Korea Welfare Panel Survey (KOWEPS), consisting of 2,463 households with householders whose working type was regular or non-regular employment(temporary, daily or public work). OLS regression analyses and Chow-tests were performed. In the regression analyses, the dependent variables for household saving were precautionary saving and precautionary asset. Precautionary saving was operationalized with the amount of average monthly saving and the ratio of average monthly saving to average monthly disposable income, and precautionary asset was operationalized with the amount of financial assets and the ratio of financial assets to net assets. The independent variables were household income, household assets, householder's working type(regular, non-regular), householder's age, sex, education level and marriage status, income level, the number of household members, housing type, debt, and public transfer income. Monthly average total consumption expenditures for household income, and net assets for household assets, the existence of spouse for marriage status, poverty for income level were used. Public transfer income was classified into three, social insurance, basic assistance and government assistance. For the analyses, Stata 11.0 version was used. The results are as follows: Householder's working type was significantly related to the precautionary saving behavior of a household. However, the precautionary saving and the precautionary asset of a household with a householder in non-regular working type was lower than those of a household with a householder in regular working type. This result is not consistent with the expectation from the perspective of precautionary saving behavior that the saving of a household with a householder in non-regular working type is expected to be higher than that of a household with a householder in regular working type. According to the analyses of the determinants for precautionary saving behavior by householder's working type, monthly average total consumption expenditures, debt, net assets, poverty, the number of household members, basic assistance were statistically significant variables. The positive relation of basic assistance to precautionary saving(the amount of average monthly saving and the ratio of average monthly saving)is a noteworthy result in the analyses of the determinants for household saving by householder's working type. The above results suggest the followings. First, it is easy to predict the unstability of economic life of a household with a householder in non-regular working type because of relatively low precautionary saving and precautionary asset. The reason for the low precautionary saving and the low precautionary asset may be a low current income of the household in spite of its willingness to save. If this reasoning is possible, it suggests that policies are needed for households with householders in non-regular working type to save. Second, the relatively low precautionary saving and precautionary asset of a household with a householder in non-regular working type suggest also their long-term economic stability. This suggests they need to try a long-term financial planning even though they have limitations to save for future because of their low current income. It is necessary to develop the financial planning for the households with unstable incomes. Third, the determinants for precautionary saving behavior by householder's working type were mostly the ones which reflect the economic condition of a household. This suggests that the economic condition of a household is a core factor for household saving. Consequently, it emphasizes the efforts for a household to acquire the adequate level of income for saving. Forth, the positive relation of basic assistance to precautionary saving(the amount of average monthly saving and the ratio of average monthly saving) suggests the possibility for a household to accumulate the precautionary saving and the precautionary asset in the channel of basic assistance.

An Exploratory Study on Consumer Behavior of Digital Banking Deposits: Focusing on Bank Loyal Customers (디지털 뱅킹 정기예금의 소비자 행동 실태에 관한 탐색적 연구 -은행 충성고객을 중심으로-)

  • Inkwan Cho;Soo Kyung Park;Bong Gyou Lee
    • Journal of Service Research and Studies
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    • v.13 no.2
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    • pp.130-145
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    • 2023
  • The digital transformation of finance is accelerating, and digital banking has already become a major banking channel. Banks have traditionally placed importance on CRM(Customer Relationship Management) and have tried to retain their loyal customers, who contribute significantly to the bank, such as long-term transactions, holding accounts with a certain balance or more, and holding loans. In this situation, this study exploratorily analyzed the consumer behavior of digital banking deposits in a major bank of Korea(1,145 samples). Statistical analysis was performed using SPSS. The main findings of the study are summarized as follows. It was found that there were differences of consumer behavior in digital banking deposits by generation, and the MZ generation used digital banking more on holidays than other generations. As a result of analyzing the behavior of existing loyal customers and regular customers of digital banking deposit, there was a significant difference in both the amount and period of the deposit. It was confirmed that the existing loyal customers of the bank also engage in consumer behavior that contributes to the bank in digital banking. In addition, the interaction between the customer type and the date of sign up for the deposit period, which is the goal setting of financial consumers, it was found that there was a significant effect. This study empirically analyzed the consumer behavior of digital banking in a situation where decrease of bank branches and encounters with digital banking. The major concepts of the consumer behavior theory are Loyal Customer, Goal Pursuit, and Habit, which were confirmed in an example of digital banking. The results of this study can suggest practical implications for existing banks and Internet-only banks, including the importance of customer management in digital banking.

The 50th Anniversary of the UNESCO World Heritage Convention: present status and challenges (유네스코 세계유산 협약 50주년, 현재 및 과제)

  • LEE Hyunkyung ;YOO Heejun ;NAM Sumi
    • Korean Journal of Heritage: History & Science
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    • v.56 no.2
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    • pp.264-279
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    • 2023
  • The 50th anniversary of the UNESCO World Heritage Convention was in 2022. In order to reflect on the present and future of the meaning of World Heritage, this paper examines the development and changes of the UNESCO World Heritage system. After promulgating the convention in 1972, the UNESCO World Heritage system prioritized the protection of heritage sites in the world that were at risk due to armed conflicts and natural disasters to bequeath heritage to the next generation. In addition, the UNESCO World Heritage's emphasis on Outstanding Universal Value represents the particular culture of human beings formed during a certain period of time, and acts as a significant source of soft power in public diplomacy. The UNESCO World Heritage might be perceived as a shared heritage that has not only become a channel to understand various national values, but also an effective medium to convey one of UNESCO's main principles, that is, peacebuilding. However, the UNESCO World Heritage is now at the center of conflicts of heritage interpretation between many stakeholders related to invisible wars, such as cultural wars, memory wars, and history wars as the social, political, and cultural contexts concerning World Heritage have dramatically shifted with the passing of time. Paying attention to such changing contexts, this paper seeks to understand the main developments in UNESCO World Heritage's discourse concerning changes to the World Heritage Operation Guidelines and heritage experts' meetings by dividing its 50-year history into five phases. Next, this paper analyzes the main shifts in keywords related to UNESCO World Heritage through UNESDOC, which is a platform on which all UNESCO publications are available. Finally, this paper discusses three main changes of UNESCO World Heritage: 1) changes in focus in World Heritage inscriptions, 2) changes in perception of World Heritage protection, and 3) changes of view on the role of the stakeholders in World Heritage. It suggests new emerging issues regarding heritage interpretation and ethics, climate change, and human rights.

Research on Factors Affecting Smartphone App Market Selection: App Market Platform Provider's Perspective (스마트폰 앱 마켓 선택에 영향을 미치는 요인에 관한 연구: 앱 마켓 플랫폼 사업자 관점으로)

  • Lee, Ho;Kim, Jae Sung;Kim, Kyung Kyu;Lee, Youngin
    • Journal of the Korea Knowledge Information Technology Society
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    • v.13 no.1
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    • pp.11-23
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    • 2018
  • This paper empirically investigates the factors that influence the consumer choice of an app market based on the rational choice theory. The app market is the only channel where a consumer can buy smartphone apps, which give various functional convenience and are considered to be a major contributor to the proliferation of smartphones. Analyses of 281 questionnaires show that usability and structural guarantees as benefit factors significantly influence the app market choice. From the cost perspectives, both monetary and non-monetary conversion costs are found to significantly influence the app market choice. On the other hand, customer trust, information quality, and market image were found to have no significant effect on app market selection. In particular, Korean app market platform providers (KT, LG U +) seem to be superior in terms of structural guarantees, such as customer center operation and damage compensation regulations, compared to overseas app market platform operators (Google). However, in the case of the Google App Market, it is pre-installed on all Android phones, so it is not inconvenient to install additional apps to use other app market. This is disadvantageous to domestic app market platform operators, and it is necessary to establish a policy solution point. In terms of operator costs, both monetary and non-monetary conversion costs have a significant impact on app market choice. In particular, non-monetary conversion costs have a negative impact on Korean app market platform operators. It can be explained that the service expectation level of the domestic app market is low and it is recognized that the time cost factor such as membership is large for new users to use. It seems to be necessary to improve the domestic app market business. Meanwhile, extant research on smartphone apps focuses on the purchase of apps themselves, but not on the selection of the app market itself. In order to fill in this gap, this study focuses on the determinants of app market selection, including the characteristics of an app market and the switching costs.

The Effect of Preferential Purchase Policy for Technologically Developed Products on Growth of SMEs (기술개발제품 우선구매 제도가 중소기업의 성장에 미치는 영향)

  • Young-Jin Kim;Yong-Seok Cho;Woo-Hyoung Kim
    • Korea Trade Review
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    • v.48 no.3
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    • pp.43-68
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    • 2023
  • In this study, in relation to "Chapter 3 Support for Priority Purchase of Technology Development Products" of the 「Market Channel Support Act」, this study investigated the positive growth impact of technology development products subject to preferential purchase on small and medium sized enterprises. The data used for empirical verification is for 371 companies that obtained certification for technology development products subject to preferential purchase in 2016 and Data from SMEs were collected from 2017 to 2021, Sales, operating profit, and net profit was identified, and empirical verification. And conducted through statistical analysis to determine whether it had a positive effect on the growth factors of SMEs. In addition, data from 225 technology development product certification companies were collected, and empirical testing was conducted through t-test analysis on the change in growth factors before and after acquiring certification. As a result of statistical analysis, it was found that the total assets, certified sales, operating profit, and net profit, which are the growth factors of a company, are all positively affected according to the type of technology development product certification. However, in the case of authentication types, some authentications showed significant negative results. In addition, significant results were derived that after acquiring certification had a positive effect on growth factors than before acquiring certification. Consistent with this conclusion, I think that it is effective for technology development-based SMEs to enter the public procurement market and utilize the technology development product priority purchase policy for market exploitation and corporate growth. And the government should strengthen the market support policy to create demand so that SMEs can enter the procurement market and actively utilize the preferential purchase system, and come up with an improvement plan so that public institutions can actively utilize the preferential purchase system.

Spatio-temporal Changes in Macrobenthic Community Structure and Benthic Environment at an Intensive Oyster Culturing Ground in Geoje-Hansan Bay, Korea (굴 양식장 밀집해역인 거제한산만의 저서동물군집 구조와 저서환경의 시.공간적 변동)

  • Yoon, Sang-Pil;Jung, Rae-Hong;Kim, Youn-Jung;Hong, Sok-Jin;Oh, Hyun-Taik;Lee, Won-Chan
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.14 no.4
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    • pp.213-228
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    • 2009
  • This study was conducted to investigate spatio-temporal changes in macrobenthic community structure and benthic environmental conditions in Geoje-Hansa Bay, which is the greatest oyster producing site in Korea. Field survey for benthic environment and macrobenthos was seasonally carried out at 15 stations covering oyster farming sites and non-farming sites from February to November, 2008. The grain size of surface sediments was dominated by very fine silt with the mean phi of about $9\;{\Phi}$ and TOC was 1.9% on average. Mean dissolved oxygen content was 8.1 mg/L and lowest in August corresponding to the 2nd degree in seawater quality criteria. Total species number was 351 and mean density was $3,675\;ind./m^2$, both of which were dominated by polychaete worms. Spatio-temporal variation in above two biological variables was great with higher values seasonally in spring and spatially in channels rather than inner bay. Dominant species were Lumbrineris longifolia (21.3%), Aphelochaeta monilaris (17.8%) and Ericthonius pugnax(6.1%), all of which are typical species of organically enriched area. From the multivariate analyses, the whole macrobenthic community was distinguished into two groups of channel and inner bay group. Spatio-temporal changes of macrobenthic community in Geoje-Hansan Bay were related to those of TOC and acid volatile sulfide (AVS). Our results showed that Geoje-Hansan Bay should be intermediately affected by organic pollution, and that such organic enrichment was more remarkable at farming stations in the inner bay.