• Title/Summary/Keyword: Estimating

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Prediction of Expected Residual Useful Life of Rubble-Mound Breakwaters Using Stochastic Gamma Process (추계학적 감마 확률과정을 이용한 경사제의 기대 잔류유효수명 예측)

  • Lee, Cheol-Eung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.31 no.3
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    • pp.158-169
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    • 2019
  • A probabilistic model that can predict the residual useful lifetime of structure is formulated by using the gamma process which is one of the stochastic processes. The formulated stochastic model can take into account both the sampling uncertainty associated with damages measured up to now and the temporal uncertainty of cumulative damage over time. A method estimating several parameters of stochastic model is additionally proposed by introducing of the least square method and the method of moments, so that the age of a structure, the operational environment, and the evolution of damage with time can be considered. Some features related to the residual useful lifetime are firstly investigated into through the sensitivity analysis on parameters under a simple setting of single damage data measured at the current age. The stochastic model are then applied to the rubble-mound breakwater straightforwardly. The parameters of gamma process can be estimated for several experimental data on the damage processes of armor rocks of rubble-mound breakwater. The expected damage levels over time, which are numerically simulated with the estimated parameters, are in very good agreement with those from the flume testing. It has been found from various numerical calculations that the probabilities exceeding the failure limit are converged to the constraint that the model must be satisfied after lasting for a long time from now. Meanwhile, the expected residual useful lifetimes evaluated from the failure probabilities are seen to be different with respect to the behavior of damage history. As the coefficient of variation of cumulative damage is becoming large, in particular, it has been shown that the expected residual useful lifetimes have significant discrepancies from those of the deterministic regression model. This is mainly due to the effect of sampling and temporal uncertainties associated with damage, by which the first time to failure tends to be widely distributed. Therefore, the stochastic model presented in this paper for predicting the residual useful lifetime of structure can properly implement the probabilistic assessment on current damage state of structure as well as take account of the temporal uncertainty of future cumulative damage.

A Study on the Sketch of Trikaya Banner Painting in the Suta-sa Temple (수타사 삼신불괘불도(三身佛掛佛圖) 초본(草本) 연구)

  • Kim, Chang Kyun
    • Korean Journal of Heritage: History & Science
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    • v.42 no.4
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    • pp.112-131
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    • 2009
  • The Trikaya Banner Painting in the Suta-sa Temple at Hongcheon-gun, Gangwon-do draws attention as it was painted not on flax but on paper, and used the water color painting technique on the sketch rather than the deep color painting technique, which is most common in Buddhist paintings created during the Chosun Dynasty. Nevertheless, there is not any information on the creation of the Trikaya Banner Painting in the painting record on the painting, in Sutasasajeok(壽陀寺史蹟), or in Sutasagogirok(壽陀寺古記錄), so it is uncertain when the painting was created. Furthermore, because it was not drawn by the deep color painting technique, it has been difficult to compare it with other banner paintings. For these reasons, the Trikaya Banner Painting has been studied little except brief introduction. In recent preservation treatment that removed multiple-layered paper from the back of the painting, however, an inked inscription written on Korean paper 118cm high and 87.5cm wide was discovered on the back. It is a kind of placard notifying a number of acts prohibited in order to follow Buddha's teachings correctly, and was found to have been written on April 15, 1690. The inked inscription is a very valuable material for estimating the creation date of the Suta-sa Trikaya Banner Painting, and provides crucial clues for approaching the contents and nature of the painting more precisely. When the image, form, and style of the Suta-sa Trikaya Banner Painting were examined and its creation date was estimated based on the inked inscription, first, the painting is presumed to have been created in around 1690 as suggested by 'the placard' attached on the back instead of a painting record. Second, the painting is highly likely to be the first standing Trikaya banner painting showing the basic icons of Trikaya banner paintings in the Chosun Dynasty since the Trikaya Banner Painting in the Gap-sa Temple in Gongju (1650). Furthermore, considering the shape of the Trikaya in the painting, screen composition, background treatment, solemn and affectionate facial expression, harmonious and adequate body proportion, etc., the painting is believed to have had a considerable influence not only on Trikaya banner paintings of similar style in the 18thcentury but also on deep-color Trikaya banner paintings in the 19thcentury. Third, although the Suta-sa Trikaya Banner Painting is not acompleted work but a sketch, it exhibits the typical water color painting technique in which the strokes are clearly visible. Thus, it is considered highly valuable in understanding and analyzing stroke styles and in studying the history of Buddhist paintings. As there are not many extant banner paintings of the same style in form and expression technique as the Suta-sa Temple Trikaya Banner Painting, this study could not make thorough comparative analysis of the work, but still it is meaningful in that it laid the ground for research on standing Trikaya banner paintings in the 18thand 19thcenturies in the Chosun Dynasty.

Study on improvement of USLE P factor considering topography and cultivation method (지형 및 경작 방법을 반영한 범용토양유실량 산정공식 보전관리 인자 개선 연구)

  • Sung, Yunsoo;Lee, Gwanjae;Lee, Gwanjae;Han, Jeongho;Kim, Jonggun;Lim, Kyoung Jae;Kim, Ki Sung
    • Journal of Wetlands Research
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    • v.21 no.2
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    • pp.163-172
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    • 2019
  • The USLE P factor is a factor that varies depending on how croplands are managed and cultivated. Previous studies tend to overestimate the amount of soil loss because the factor was estimated from the slope of the watershed rather than the estimate of each cultivated land. In addition, the accuracy of estimating the soil loss is decreasing due to the fact that the factor is calculated without considering various conditions of cultivated land defined by Wishmeier and Smith. In order to overcome these problems, the Ministry of Environment (MOE) has proposed to establish the topsoil notification and calculate the P factor according to the cultivation methods (e.g., tillage system, support practice). However, it is required to apply the conditions proposed in the United States to domestic circumstances as it is causing uncertainties. Thus, this study selected the watersheds where soil loss was serious (Haean, Jaun, Banbyeoncheon), measured the actual slopes and slope lengths, and examined the crop, tillage systems, and support practice for each cultivated land. The P factors were recalculated considering the actual conditions of cultivated land and compared to the factors proposed by the previous studies (MOE). As the result of the study, the P factors calculated based on the previous studies were 0.8 ~ 1.0 in three watersheds. On the other hand, it is confirmed that there is a significant difference between the factors notified by MOE and estimated by reflecting the topography and cultivation methods in this study. Therefore, it is considered that the research for developing the cultivation conditions to calculate the P factor suitable for the domestic environment should be continuously carried out.

Development and evaluation of semi-quantitative food frequency questionnaire for marriage migrant women in multicultural families (다문화가정 결혼이주여성 대상 식사조사를 위한 반정량 식품섭취빈도 조사지의 개발 및 평가)

  • Kim, Jung-Hyun;Kim, Oh Yoen;Lee, Min June;Park, Eunju
    • Journal of Nutrition and Health
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    • v.54 no.1
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    • pp.76-94
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    • 2021
  • Purpose: This study was implemented to develop and validate a semi-quantitative food frequency questionnaire (SQ-FFQ) to assess the dietary intake of married migrant women in multicultural families. Methods: The SQ-FFQ consisting of 41 food items was selected based on the information of frequently consumed foods from the preliminary studies on dietary intake survey for married migrant women or a Korean Health and Nutrition Examination survey. Thirty-five subjects who visited the Multicultural Family Support Center in Seoul and Daejeon area completed their three-day diet records and SQ-FFQ 2 times. The reproducibility and relative validity of SQ-FFQ were assessed by comparing the 1st and 2nd SQ-FFQ and by comparison with the three-day diet records, respectively. Results: The reliability of SQ-FFQ, which was examined 1-2 weeks apart, showed no significant difference in the energy and macronutrient intake (carbohydrate, fat, protein), while the average intakes of vitamin A, riboflavin, calcium, and potassium were slightly higher in the 2nd than 1st SQ-FFQ. All correlation coefficients for the reliability for nutrients were statistically significant, ranging from 0.453 to 0.885. The mean intakes of energy, carbohydrate, vitamin C, thiamin, folate, vitamin B12, calcium, and sodium obtained from the SQ-FFQ were greater than those of the 3-day dietary records. The Spearman's correlation coefficient between the 2 methods was the highest for plant fat (r = 0.602; p < 0.001) and relatively higher for energy, carbohydrate, fat, and thiamin ranging from 0.512 to 0.599; and protein, riboflavin, niacin, folate ranging from 0.335 to 0.499, while no significant correlation was observed for vitamin A, C, calcium, iron, and sodium. Conclusion: The developed SQ-FFQ for married migrant women in multicultural families in this study appears to be useful for estimating the nutritional status, particularly energy, carbohydrates, fat, and vitamin B group.

Production Date and Patrons of Korean Treasure #978: Transcription of the Avatamsaka Sutra (Zhou Version) in Gold on White Paper (보물 제978호 <백지금니대방광불화엄경(白紙金泥大方廣佛華嚴經) 권(卷)29>의 조성 연대 및 발원자 고찰)

  • Won, Seunghyun
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.98
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    • pp.78-103
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    • 2020
  • Transcribed Buddhist sutras generally consist of a frontispiece illustration, sutra illustrations, and sutra text, although some parts may be lost over time. Most transcribed sutras originally include an official record of the transcription (saseonggi) at either the beginning or end of the volume, which document various details of the production, including who commissioned the sutra and when it was transcribed. If such records are unavailable or difficult to decipher, the date of the sutra can only be estimated by comparison to other works with known production dates. This is the case with Korean Treasure #978, the "Transcription of the Avatamsaka Sutra (Zhou Version) in Gold on White Paper" (hereinafter, "Avatamsaka Sutra, Volume 29"), which does not contain any details of its production. Based on formal comparisons, the volume has been estimated to date from the early Joseon period. Important criteria for estimating the production date include the type of calligraphy script and the overall expression of the sutra illustrations. However, these features are missing from some early Joseon sutras, making it difficult to definitively assert which characteristics are representative of the period. Also, transcribed sutras from the late Goryeo period (after 1350) and early Joseon period are often very similar in terms of the expression of the frontispiece illustrations and sutra illustrations. From the late Goryeo period through the early Joseon period, the illustrations of transcribed sutras, which had previously been relatively detailed and realistic, gradually became more formalized and stylized. Significantly, Avatamsaka Sutra, Volume 29 includes illustrations showing both styles of expression (i.e., realistic and formalized). Moreover, the hemp leaf design on the frontispiece and the border around the sutra illustrations are unique features that have never been seen on any other transcribed sutras. Notably, however, Avatamsaka Sutra in Gold on White Paper, Volume 26 (hereinafter, "Avatamsaka Sutra, Volume 26"), which has not yet been introduced in academic research, is complete with frontispiece, sutra illustrations, and sutra text. This sutra is identical to Avatamsaka Sutra, Volume 29 in size, composition, and details, and is thus estimated to have been produced at the same time and by the same patrons. According to the record at the end of the volume, Avatamsaka Sutra, Volume 26 was commissioned in 1348 by Gi Cheol (d. 1365), which corresponds to the estimated date of Avatamsaka Sutra, Volume 29 derived by formal comparison. Based on this new information, Avatamsaka Sutra, Volume 29 was likely produced in the late Goryeo period rather than the early Joseon period, as has previously been presumed. The new study of Avatamsaka Sutra, Volume 26 also seems to confirm that both sutras were transcribed by highly skilled artisans in 1348 of the late Goryeo period, a transitional phase in the expression of sutra illustrations.

Application of Spectral Indices to Drone-based Multispectral Remote Sensing for Algal Bloom Monitoring in the River (하천 녹조 모니터링을 위한 드론 다중분광영상의 분광지수 적용성 평가)

  • Choe, Eunyoung;Jung, Kyung Mi;Yoon, Jong-Su;Jang, Jong Hee;Kim, Mi-Jung;Lee, Ho Joong
    • Korean Journal of Remote Sensing
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    • v.37 no.3
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    • pp.419-430
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    • 2021
  • Remote sensing techniques using drone-based multispectral image were studied for fast and two-dimensional monitoring of algal blooms in the river. Drone is anticipated to be useful for algal bloom monitoring because of easy access to the field, high spatial resolution, and lowering atmospheric light scattering. In addition, application of multispectral sensors could make image processing and analysis procedures simple, fast, and standardized. Spectral indices derived from the active spectrum of photosynthetic pigments in terrestrial plants and phytoplankton were tested for estimating chlorophyll-a concentrations (Chl-a conc.) from drone-based multispectral image. Spectral indices containing the red-edge band showed high relationships with Chl-a conc. and especially, 3-band model (3BM) and normalized difference chlorophyll index (NDCI) were performed well (R2=0.86, RMSE=7.5). NDCI uses just two spectral bands, red and red-edge, and provides normalized values, so that data processing becomes simple and rapid. The 3BM which was tuned for accurate prediction of Chl-a conc. in productive water bodies adopts originally two spectral bands in the red-edge range, 720 and 760 nm, but here, the near-infrared band replaced the longer red-edge band because the multispectral sensor in this study had only one shorter red-edge band. This index is expected to predict more accurately Chl-a conc. using the sensor specialized with the red-edge range.

Economic Feasibility of REDD Project for Preventing Deforestation in North Korea (북한 산림전용 방지수단으로서의 REDD 사업의 경제적 타당성 분석)

  • Jo, Jang Hwan;KOO, Ja Choon;Youn, Yeo Chang
    • Journal of Korean Society of Forest Science
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    • v.100 no.4
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    • pp.630-638
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    • 2011
  • This study aims to verify the economic validity of the REDD project in North Korea by estimating the potential carbon credits and the cost of REDD project. The REDD potential credits of North Korea are estimated based on the international statistics of forest area and population from 1990 to 2010, and the cost of REDD project is estimated indirectly by annual land opportunity cost of agriculture assuming that South Korea will aid the food production per area in North Korea. When the 25% reduction scenario was applied to the annual deforestation rate in North Korea, the potential REDD credits were estimated to be $4,232million{\sim}5,290milliontCO_2eq.$ for 20 years. It would account for 28~35% of South Korea's national medium-term greenhouse gas reduction target. On the other hand, the break-even price of REDD project was calculated as the profit of agriculture in the land available by forest conversion in North Korea. It was estimated to be 19.19$/$tCO_2eq.$ when the non-permanence risk of forest conserved through a REDD contract is assumed to be 20%. This price is higher than the price of REDD carbon credit 5$/$tCO_2eq.$ dealt in the 2010 voluntary carbon market, leading to no economic feasibility. However, REDD project provides co-benefits besides climate mitigation. As previous studies indicate, the break-even price is lower than 20$/$tCO_2eq.$, which is the social marginal cost of greenhouse gas emissions by loss of forest. Therefore REDD in North Korea can be justified against the social benefits. The economic feasibility of REDD project in North Korea can be largely influenced by the risk percentage. Thus, North Korean REDD project needs a strong guarantee and involvement by the government and people of North Korea to assure the project's economic feasibility.

Feasibility of Tax Increase in Korean Welfare State via Estimation of Optimal Tax burden Ratio (적정조세부담률 추정을 통한 한국 복지국가 증세가능성에 관한 연구)

  • Kim, SeongWook
    • 한국사회정책
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    • v.20 no.3
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    • pp.77-115
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    • 2013
  • The purpose of this study is to present empirical evidence for discussion of financing social welfare via estimating optimal tax burden in the main member countries of the OECD by using Hausman-Taylor method considering endogeneity of explanatory variables. Also, the author produced an international tax comparison index reflecting theoretical hypotheses on revenue-expenditure nexus within a model to compare real tax burden by countries and to examine feasibility of tax increase in Korea. As a result of the analysis, the higher the level of tax burden was, the higher the level of welfare expenditure was, indicating the connection between high burden and high welfare from the aspect of scale. The results also indicated that the subject countries recently entered into the state of low tax burden. Meanwhile, Korea had maintained low burden until the late 1990s but the tax burden soared up since the financial crisis related to the IMF. However, due to the impact of foreign economy and the tax reduction policy, it reentered into the low-burden state after 2009. On the other hand, the degree of social welfare expenditure's reducing tax burden has been gradually enhanced since the crisis. In this context, the current optimal tax burden ratio of Korea as of 2010 may be 25.8%~26.5% of GDP based on input of welfare expenditure variables, a percent that Korea was investigated to be a 'high tax burden-low ITC' country whose tax increase of 0.7~1.4%p may be feasible and that the success of tax system reform for tax increase might be higher probability when compare to others. However, measures of increasing social security contributions and consumption tax were analyzed to be improper from the aspect of managing finance when compared to increase in other tax items, considering the relatively higher ITC. Tax increase is not necessarily required though there may be room for tax increase; the optimal tax burden ratio can be understood as the level that may be achieved on average when compared to other nations, not as the "proper" level. Thus, discussion of tax increase should be accompanied with comprehensive understanding of models of economic developmental difference from nations and institutional & historical attributes included in specific tax mix.

Dam-Heon Hong Dae Yong's : A part of the BukHak School's Understanding on The Great Learning (담헌 홍대용의 <대학문의(大學問疑)> : 북학파의 『대학』 이해의 일단(一端))

  • Ahn, Woe Soon
    • (The)Study of the Eastern Classic
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    • no.33
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    • pp.385-411
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    • 2008
  • This thesis aims at examining his understandings about the The Great Learning centering on the of the founder of the YiYongHuSaeng School (利用厚生學派: A school who pursued prosperous economy and welfare of people) orthe BukHak School(北學派: A positive school that pursued mercantilism) from the Joseon Dynasty, Dam-Heon Hong Dae Yong (1731-1783). 1) From what is indicated in the , his studies mainly focused on the annotations from DaeHakJangGuDaeJeonJipJu ("大學章句大全集註": A book that edited different phrases from the Great Learning into chapters and paragraphs), Questioning of the Great Learning", and "JuJaUhRyu (朱子語類: A book of Confucian literature written by Yeo Jung Deok" of Zhu Xi who was a representative scholar of the Neo-Confucianism in the Song Dynasty. 2) Acknowledging entirely the arguing points of Zhu Xi, he is taking a critical position in a way that partial doubts are divided into seven chapters and questioned. 3) For the main characteristic and direction of the questioning, he is estimating that Zhu Xi only stressed the 'means' and 'interior' out of the world of 'means and ends' and 'interior and exterior' in Zhu Xi's recognizing and handling cases; instead, he emphasized putting equivalent value on the 'ends' and 'exterior' as well. 4) In fact, such questions raised partially were misconceived since they were not carried out through profound understanding nor systematic logic expansion of what Zhu Xi insisted. 5) Despite this, at the point where Neo-Confucian thoughts were fixed and weakened only with its form left in the late Joseon Dynasty, his perspective on the study of Confucian classics that the 'ends' and 'exterior' should be as equally valued as the 'means' and 'interior' by examining through the core text of the Neo-Confucianism, The Great Learning has its significance in his YiYongHuSaeng dogma that says politicians, by all means, should provide the ruled with economic convenience and welfare and this is their very right virtue.

A Study of the Current State of the Garden and Restoration Proposal for the Original Garden of Yi Cheon-bo's Historic House in Gapyeong (가평 이천보(李天輔) 고가(古家)의 정원 현황과 원형 복원을 위한 제안)

  • Rho, Jaehyun;Choi, Seunghee;Jang, Hyeyoung
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.118-135
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    • 2020
  • It is not uncommon in Korea to see the structure and function of a garden remain intact as well as its form. Yi Cheon-bo's Historic House (Gyeonggi-do Cultural Heritage Item No. 55), located in Sang-myeon, Gapyeong-gun, Gyeonggi-do, is considered an example of very valuable garden heritage, although its family history, location, and remaining buildings and natural cultural assets are not fully intact. Along with Yi Cheon-bo's Historic House, this study attempted to explore the possibility of restoration of the forest houses and gardens by highlighting the high value of Yi Cheon-bo's Historic House through research into the typical layout of private households in northern Gyeonggi Province and Gapyeong County, comparative review of aerial photographs from 1954, and interviews with those involved. The results of the study are as follows: In this study, the presence of Banggye-dongmun and Bansukam in the Banggyecheon area, where the location of the garden was well-preserved, was examined across the landscape of the outer garden, while the location of Yi Cheon-bo's Historic House, the appearance of feng shui, and the viewing axis were considered. Also, the appearance of the lost main house was inferred from the arrangement and shape of the Sarangchae and Haengrangchae that remain in the original garden, and the asymmetry of the Sarangchae Numaru and the hapgak shape on the side of the roof. In addition, the three tablets (Pyeonaeks) of Sanggodang (尙古堂), Bangyejeongsa (磻溪精舍), and Okgyeongsanbang (玉聲山房) were used to infer the landscape, use, and symbolism of the men's quarters. Also, a survey was conducted on the trees that existed or existed in the high prices. Incidentally, it was confirmed that information on boards and cultural properties of Yeonha-ri juniper (Gyeonggi-do Monument No. 61) was recorded to a much lesser extent than the actual required standard, and the juniper trees remaining in the front of Haengrangchae should also be re-evaluated after speculation. On the other hand, as a result of estimating the original shape as a way of pursuing completeness of the garden through restoration of the lost women's quarters and shrine, it is estimated that the main house was placed in the form of a '口' or a 'be warped 口' on the right (north) side of the men's quarters. By synthesizing these results, a restoration alternative for Yi Cheon-bo's Historic House was suggested.