• Title/Summary/Keyword: Horizontal stress

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Morphological Adaptation of Zostera marina L. to Ocean Currents in Korea (한국산 거머리말(Zostera marina L.)의 해류에 대한 형태적 적응)

  • Lim, Dong-Ok;Yun, Jang-Tak;Han, Kyung-Shik
    • Korean Journal of Environment and Ecology
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    • v.23 no.5
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    • pp.431-438
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    • 2009
  • The main purpose of this research is to prepare and provide basic materials for the propagational strategy of eelgrass by investigating on the morphological adaptation of Korean Zostera marina to ocean currents. An eelgrass plant mainly consists of rhizome, leaf sheath, leaves and roots. The rhizome is the horizontal stem of the plant that serves as the backbone from which the leaves and roots emerge. The leaf sheath is the bundle at the base of the leaves that holds the leaves together, protecting the meristem, the primary growth point of the shoot. Leaves originate from a meristem which is protected by a sheath at the actively growing end of the rhizome. As the shoot grows, the rhizome elongates, moving across or within the sediment, forming roots as it progresses. The aggregated leaves from the leaf sheath are found to have two cell layers on one side and multiple layers of airy tissues called aerenchyma on the other. The aerenchyma tissues are developed in multi-layered cell structures surrounding the veins which are formed in the leaf sheath. Generative shoots are made of rhizomes, which are circular or ovoidal, stem, and spathe and spadix. The transverse section of rhizome and the stem and central floral axis is found to be circular, ovoid and in the shape of convex respectively, and the vascular bundle, which is a part of transport system, has one large tube in the center and two small tubes on both sides. The layers of collenchyma cells numbered from 12 to 15 in the stem, and from 7 to 12 in the rhizome. The seed coat is composed of sclereids, small bundles of sclerenchyma tissues, which prevent the influx of sea water from the outside and help endure the environmental stress. In conclusion, alternative multi-layer structure in circular, convex type aggregated leaf base are interpreted to morphological adaption as doing tolerable elastic structure through movement of seawater. The generative shoots develop long slim stem and branches in circular or ovoidal shapes to minimize the adverse impacts of sea current, which can be interpreted as the plant's morphological adaptation to its environment.

Stress distribution following face mask application using different finite element models according to Hounsfield unit values in CT images (CT상의 HU 수치에 따른 상악골 전방견인 효과의 유한요소 분석)

  • Chung, Dong-Hwa
    • The korean journal of orthodontics
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    • v.36 no.6
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    • pp.412-421
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    • 2006
  • Objective: The result of finite element analysis depends on material properties, structural expression, density of element, and boundar or loading conditions. To represent proper elastic behavior, a finite element model was made using Hounsfield unit (HU) values in CT images. Methods: A 13 year 6 month old male was used as the subject. A 3 dimensional visualizing program, Mimics, was used to build a 3D object from the DICOM file which was acquired from the CT images. Model 1 was established by giving 24 material properties according to HU. Model 2 was constructed by the conventional method which provides 2 material properties. Protraction force of 500g was applied at a 45 degree downward angle from Frankfort horizontal (FH) plane. Results: Model 1 showed a more flexible response on the first premolar region which had more forward and downward movement of the maxillary anterior segment. Maxilla was bent on the sagittal plane and frontal plane. Model 2 revealed less movement in all directions. It moved downward on the anterior part and upward on the posterior part, which is clockwise rotation of the maxilla. Conclusion: These results signify that different outcomes of finite element analysis can occur according to the given material properties and it is recommended to use HU values for more accurate results.

Current Research Trend of Postharvest Technology for Chrysanthemum (국화 수확 후 관리기술의 최근 연구 동향)

  • Kim, Su-Jeong;Lee, Seung-Koo;Kim, Ki-Sun
    • Korean Journal of Plant Resources
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    • v.25 no.1
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    • pp.156-168
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    • 2012
  • Chrysanthemum is a cut flower species that normally lasts for 1 to 2 weeks, in some cases 3-4 weeks. This has been attributed to low ethylene production during senescence. Reduction in cut flower quality has been attributed to the formation of air embolisms that partially or completely blocks the water transport from the vase solution to the rest of the cut flower stem, increasing hydraulic resistance which may cause severe water stress, yellowing, wilting of leaf, and chlorophyll degradation. Standard type chrysanthemum can be harvested when buds were still tightly closed and then fully opened with the simple bud-opening solution. Standard type chrysanthemum can also be harvested when the minimum size of the inflorescence is about 5-6 cm bud which opened into the first flower full-sized flower. While spray varieties can be harvested when 2-4 most mature flowers have opened (40% opening). Cut flowers are sorted by stem length, weight, condition, and so on. Standard chrysanthemum is 80 cm length for standard type and 70cm for spray type. Pre-treatment with a STS, plant regulator such as GA, BA, 1-MCP, chrysal, germicide, and sucrose, significantly improved the vase life and quality of cut flowers. It is well established that vase solutions containing sugar can improve the vase life of cut chrysanthemum. Chrysanthemum is normally packed in standard horizontal fiberboard boxes. Chrysanthemum should normally be stored at $5{\sim}7^{\circ}C$. Precooling resulted in reduction in respiration, decomposition, and transpiration activities as well as decoloration retardation. There was significant difference between "wet" storage in 3 weeks and "dry" storage in 2 weeks. In separate pulsing solution trials, various germicides were tested, as well as PGRs to maintain the green color of leaves and turgidity. Prolonging vase life was attained with the application of optimal solution such as HQS, $AgNO_3$, GA, BA and sucrose. This also retarded senescence in leaves of cut flower stems. Fresh cut chrysanthemum can be transported using a refrigerated van with $5{\sim}7^{\circ}C$. Increasing consumption and usage of cut chrysanthemum of various cultivars would require efficient transport system, and effective information exchange among producer, wholesaler, and consumer.

Temperature and Solar Radiation Prediction Performance of High-resolution KMAPP Model in Agricultural Areas: Clear Sky Case Studies in Cheorwon and Jeonbuk Province (고해상도 규모상세화모델 KMAPP의 농업지역 기온 및 일사량 예측 성능: 맑은 날 철원 및 전북 사례 연구)

  • Shin, Seoleun;Lee, Seung-Jae;Noh, Ilseok;Kim, Soo-Hyun;So, Yun-Young;Lee, Seoyeon;Min, Byung Hoon;Kim, Kyu Rang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.22 no.4
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    • pp.312-326
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    • 2020
  • Generation of weather forecasts at 100 m resolution through a statistical downscaling process was implemented by Korea Meteorological Administration Post- Processing (KMAPP) system. The KMAPP data started to be used in various industries such as hydrologic, agricultural, and renewable energy, sports, etc. Cheorwon area and Jeonbuk area have horizontal planes in a relatively wide range in Korea, where there are many complex mountainous areas. Cheorwon, which has a large number of in-situ and remotely sensed phenological data over large-scale rice paddy cultivation areas, is considered as an appropriate area for verifying KMAPP prediction performance in agricultural areas. In this study, the performance of predicting KMAPP temperature changes according to ecological changes in agricultural areas in Cheorwon was compared and verified using KMA and National Center for AgroMeteorology (NCAM) observations. Also, during the heat wave in Jeonbuk Province, solar radiation forecast was verified using Automated Synoptic Observing System (ASOS) data to review the usefulness of KMAPP forecast data as input data for application models such as livestock heat stress models. Although there is a limit to the need for more cases to be collected and selected, the improvement in post-harvest temperature forecasting performance in agricultural areas over ordinary residential areas has led to indirect guesses of the biophysical and phenological effects on forecasting accuracy. In the case of solar radiation prediction, it is expected that KMAPP data will be used in the application model as detailed regional forecast data, as it tends to be consistent with observed values, although errors are inevitable due to human activity in agricultural land and data unit conversion.

Granite Dike Swarm and U-Pb Ages in the Ueumdo, Hwaseong City, Korea (경기도 화성시 우음도 일원의 화강암 암맥군과 U-Pb 연령)

  • Chae, Yong-Un;Kang, Hee-Cheol;Kim, Jong-Sun;Park, Jeong-Woong;Ha, Sujin;Lim, Hyoun Soo;Shin, Seungwon;Kim, Hyeong Soo
    • Journal of the Korean earth science society
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    • v.43 no.5
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    • pp.618-638
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    • 2022
  • The Middle Jurassic granite dike swarm intruding into the Paleoproterozoic banded gneiss is pervasively observed in Ueumdo, Hwaseong City, mid-western Gyeonggi Massif. Based on their cross-cutting relationships in a representative outcrop, there are four dikes (UE-A, UE-C, UE-D, UE-E), and depending on the direction, there are three granite dike groups, which are NW- (UE-A dike), NW to WNW- (UE-C dike), and NE-trending (UE-D and UE-E dikes). These granite dikes are massive, medium-to coarse-grained biotite granites, and their relative ages observed in outcrops are in the order of UE-A, UE-D (=UE-E), and UE-C. The geometric analysis of the dikes indicates that the UE-A and UE-C dikes intrude under approximately NE-SW trending horizontal minimum stress fields. The UE-A dike, which showed a relatively low average SiO2 content by major element analysis, is a product of early magma differentiation compared to other dikes; therefore, it is consistent with the relative age of each dike. The 206Pb/238U weighted mean ages for each dike obtained from SHRIMP zircon U-Pb dating were calculated to be 167 Ma (UE-A), 164 Ma (UE-C), 167 Ma (UE-D), and 167 Ma (UE-E), respectively. The samples of the UE-A, UE-D, and UE-E dikes showed very similar ages. The UE-C dike shows the youngest age, which is consistent with the results of the relative age in the outcrops and major element analysis. Therefore, the granite dikes intruded into the Middle Jurassic (approximately 167 and 164 Ma), coinciding with those of the Gyeonggi Massif, where the Middle Jurassic plutons are geographically widely distributed. This result indicates that the wide occurrence of the Middle Jurassic plutons on the Gyeonggi Massif was formed as a result of igneous activity moving in the northwest direction with the shallower subduction angle of the subducting oceanic plate during the Jurassic.

Deformation History of the Pohang Basin in the Heunghae Area, Pohang and Consideration on Characteristics of Coseismic Ground Deformations of the 2017 Pohang Earthquake (Mw 5.4), Korea (포항 흥해지역에서 포항분지의 변형작용사와 2017 포항지진(Mw 5.4) 동시성 지표변형 특성 고찰)

  • Ji-Hoon, Kang
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.4
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    • pp.485-505
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    • 2022
  • On November 15, 2017, a Mw 5.4 Pohang Earthquake occurred at about 4 km hypocenter in the Heunghae area, and caused great damage to Pohang city, Korea. In the Heunghae area, which is the central part of the Pohang Basin, the Cretaceous Gyeongsang Supergroup and the Late Cretaceous to Early Paleogene Bulguksa igneous rocks as basement rocks and the Neogene Yeonil Group as the fillings of the Pohang Basin, are distributed. In this paper, structural and geological researches on the crustal deformations (folds, faults, joints) in the Pohang Basin and the coseismic ground deformations (sand volcanoes, ground cracks, pup-up structures) of Pohang Earthquake were carried out, and the deformation history of the Pohang Basin and characteristics of the coseismic ground deformations were considered. The crustal deformations were formed through at least five deformation stages before the Quaternary faulting: forming stages of the normal-slip (Gokgang fault) faults which strike (N)NE and dip at high angles, and the high-angle joints of E-W trend regionally recognized in Yeonil Group and the faults (sub)parallel to them, and the conjugate normal-slip faults (Heunghae fault and Hyeongsan fault) which strike E-W and dip at middle or low angles and the accompanying E-W folds, and the conjugate strike-slip faults dipped at high angles in which the (N)NW and E-W (NE) striking fault sets show the (reverse) sinistral and dextral strike-slips, respectively, and the conjugate reverse-slip faults in which the NNE and NNW striking fault sets dip at middle angles and the accompanying N-S folds. Sand volcanoes often exhibit linear arrangements (sub)parallel to ground cracks in the coseismic ground deformations. The N-S or (N)NE trending pop-up structures and ground cracks and E-W or (W)NW trending ground were formed by the reverse-slip movement of the earthquake source fault and the accompanying buckling folding of its hanging wall due to the maximum horizontal stress of the Pohang Earthquake source. These structural activities occurred extensively in the Heunghae area, which is at the hanging wall of the earthquake source fault, and caused enormous property damages here.

Reinforcing Effects around Face of Soil-Tunnel by Crown & Face-Reinforcing - Large Scale Model Testing (천단 및 막장면 수평보강에 의한 토사터널 보강효과 - 실대형실험)

  • Kwon Oh-Yeob;Choi Yong-Ki;Woo Sang-Baik;Shin Jong-Ho
    • Journal of the Korean Geotechnical Society
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    • v.22 no.6
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    • pp.71-82
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    • 2006
  • One of the most popular pre-reinforcement methods of tunnel heading in cohesionless soils would be the fore-polling of grouted pipes, known as RPUM (reinforced protective umbrella method) or UAM (umbrella arch method). This technique allows safe excavation even in poor ground conditions by creating longitudinal arch parallel to the tunnel axis as the tunnel advances. Some previous studies on the reinforcing effects have been performed using numerical methods and/or laboratory-based small scale model tests. The complexity of boundary conditions imposes difficulties in representing the tunnelling procedure in laboratory tests and theoretical approaches. Full-scale study to identify reinforcing effects of the tunnel heading has rarely been carried out so far. In this study, a large scale model testing for a tunnel in granular soils was performed. Reinforcing patterns considered are four cases, Non-Reinforced, Crown-Reinforced, Crown & Face-Reinforced, and Face-Reinforced. The behavior of ground and pipes as reinforcing member were fully measured as the surcharge pressure applied. The influences of reinforcing pattern, pipe length, and face reinforcement were investigated in terms of stress and displacement. It is revealed that only the Face-Reinforced has decreased sufficiently both vertical settlement in tunnel heading and horizontal displacement on the face. Vertical stresses along the tunnel axis were concentrated in tunnel heading from the test results, so the heading should be reinforced before tunnel advancing. Most of maximum axial forces and bending moments for Crown-reinforced were measured at 0.75D from the face. Also it should be recommended that the minimum length of the pipe is more than l.0D for crown reinforcement.

Space Usage and Satisfaction with Privacy in General Hospital Inpatients (종합병원 입원환자의 공간사용 및 프라이버시 만족도)

  • Choi, In Young;Park, Hey Kyung
    • Korea Science and Art Forum
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    • v.36
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    • pp.391-400
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    • 2018
  • To ensure a user-centered treatment environment, hospital construction needs an approach that is not centered on functional aspects such as efficiency or economic feasibility but on the consideration of needs as reflected in user psychology and behavior. Patients who are physically and psychologically vulnerable experience psychological pressure when they are placed in an unfamiliar environment. Most of existing studies however focus on the evaluation of the physical environment, without paying attention to the psychological or behavioral approach to anxiety and stress that patients may experience in a special environment that a hospital may be to them. This study examines general hospital inpatients to understand the usage of major space available and their satisfaction with privacy. This study provides useful primary information needed for the user-centered design of general hospital for improved patient health and welfare. For the purpose of the study, literature review, site investigation, and survey were conducted. Major functional space and privacy in general hospitals were studied, and the site investigation was performed to identify the plans and their status. Survey was also performed to understand the usage of functional space and satisfaction with such space usage as well as satisfaction with privacy. The findings were as follows: (1) Space usage was rated as average in general. It was found that patients used their rooms and lobby on a daily basis. By age, the usage was highest in the group in their 40s; the usage was relatively lower in the groups in their 30s or younger. (2) Space satisfaction was above average, indicating that patients were fairly satisfied. Satisfaction was highest in the lobby space designed with distinct features. By case, satisfaction was highest in Case B, characterized by its wide horizontal space in the rural settings. (3) Satisfaction with privacy in hospital was average, indicating that the demand for privacy was relatively higher but what patients receive in return was lower than their expectation. It was also found that satisfaction with privacy was a crucial element that affected the overall satisfaction with hospital.

Showing Filial Piety: Ancestral Burial Ground on the Inwangsan Mountain at the National Museum of Korea (과시된 효심: 국립중앙박물관 소장 <인왕선영도(仁旺先塋圖)> 연구)

  • Lee, Jaeho
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.96
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    • pp.123-154
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    • 2019
  • Ancestral Burial Ground on the Inwangsan Mountain is a ten-panel folding screen with images and postscripts. Commissioned by Bak Gyeong-bin (dates unknown), this screen was painted by Jo Jung-muk (1820-after 1894) in 1868. The postscripts were written by Hong Seon-ju (dates unknown). The National Museum of Korea restored this painting, which had been housed in the museum on separate sheets, to its original folding screen format. The museum also opened the screen to the public for the first time at the special exhibition Through the Eyes of Joseon Painters: Real Scenery Landscapes of Korea held from July 23 to September 22, 2019. Ancestral Burial Ground on the Inwangsan Mountain depicts real scenery on the western slopes of Inwangsan Mountain spanning present-day Hongje-dong and Hongeun-dong in Seodaemun-gu, Seoul. In the distance, the Bukhansan Mountain ridges are illustrated. The painting also bears place names, including Inwangsan Mountain, Chumohyeon Hill, Hongjewon Inn, Samgaksan Mountain, Daenammun Gate, and Mireukdang Hall. The names and depictions of these places show similarities to those found on late Joseon maps. Jo Jung-muk is thought to have studied the geographical information marked on maps so as to illustrate a broad landscape in this painting. Field trips to the real scenery depicted in the painting have revealed that Jo exaggerated or omitted natural features and blended and arranged them into a row for the purposes of the horizontal picture plane. Jo Jung-muk was a painter proficient at drawing conventional landscapes in the style of the Southern School of Chinese painting. Details in Ancestral Burial Ground on the Inwangsan Mountain reflect the painting style of the School of Four Wangs. Jo also applied a more decorative style to some areas. The nineteenth-century court painters of the Dohwaseo(Royal Bureau of Painting), including Jo, employed such decorative painting styles by drawing houses based on painting manuals, applying dots formed like sprinkled black pepper to depict mounds of earth and illustrating flowers by dotted thick pigment. Moreover, Ancestral Burial Ground on the Inwangsan Mountain shows the individualistic style of Jeong Seon(1676~1759) in the rocks drawn with sweeping brushstrokes in dark ink, the massiveness of the mountain terrain, and the pine trees simply depicted using horizontal brushstrokes. Jo Jung-muk is presumed to have borrowed the authority and styles of Jeong Seon, who was well-known for his real scenery landscapes of Inwangsan Mountain. Nonetheless, the painting lacks an spontaneous sense of space and fails in conveying an impression of actual sites. Additionally, the excessively grand screen does not allow Jo Jung-muk to fully express his own style. In Ancestral Burial Ground on the Inwangsan Mountain, the texts of the postscripts nicely correspond to the images depicted. Their contents can be divided into six parts: (1) the occupant of the tomb and the reason for its relocation; (2) the location and geomancy of the tomb; (3) memorial services held at the tomb and mysterious responses received during the memorial services; (4) cooperation among villagers to manage the tomb; (5) the filial piety of Bak Gyeong-bin, who commissioned the painting and guarded the tomb; and (6) significance of the postscripts. The second part in particular is faithfully depicted in the painting since it can easily be visualized. According to the fifth part revealing the motive for the production of the painting, the commissioner Bak Gyeongbin was satisfied with the painting, stating that "it appears impeccable and is just as if the tomb were newly built." The composition of the natural features in a row as if explaining each one lacks painterly beauty, but it does succeed in providing information on the geomantic topography of the gravesite. A fair number of the existing depictions of gravesites are woodblock prints of family gravesites produced after the eighteenth century. Most of these are included in genealogical records and anthologies. According to sixteenth- and seventeenth-century historical records, hanging scrolls of family gravesites served as objects of worship. Bowing in front of these paintings was considered a substitute ritual when descendants could not physically be present to maintain their parents' or other ancestors' tombs. Han Hyo-won (1468-1534) and Jo Sil-gul (1591-1658) commissioned the production of family burial ground paintings and asked distinguished figures of the time to write a preface for the paintings, thus showing off their filial piety. Such examples are considered precedents for Ancestral Burial Ground on the Inwangsan Mountain. Hermitage of the Recluse Seokjeong in a private collection and Old Villa in Hwagae County at the National Museum of Korea are not paintings of family gravesites. However, they serve as references for seventeenth-century paintings depicting family gravesites in that they are hanging scrolls in the style of the paintings of literary gatherings and they illustrate geomancy. As an object of worship, Ancestral Burial Ground on the Inwangsan Mountain recalls a portrait. As indicated in the postscripts, the painting made Bak Gyeong-bin "feel like hearing his father's cough and seeing his attitudes and behaviors with my eyes." The fable of Xu Xiaosu, who gazed at the portrait of his father day and night, is reflected in this gravesite painting evoking a deceased parent. It is still unclear why Bak Gyeong-bin commissioned Ancestral Burial Ground on the Inwangsan Mountain to be produced as a real scenery landscape in the folding screen format rather than a hanging scroll or woodblock print, the conventional formats for a family gravesite paintings. In the nineteenth century, commoners came to produce numerous folding screens for use during the four rites of coming of age, marriage, burial, and ancestral rituals. However, they did not always use the screens in accordance with the nature of these rites. In the Ancestral Burial Ground on the Inwangsan Mountain, the real scenery landscape appears to have been emphasized more than the image of the gravesite in order to allow the screen to be applied during different rituals or for use to decorate space. The burial mound, which should be the essence of Ancestral Burial Ground on the Inwangsan Mountain, might have been obscured in order to hide its violation of the prohibition on the construction of tombs on the four mountains around the capital. At the western foot of Inwangsan Mountain, which was illustrated in this painting, the construction of tombs was forbidden. In 1832, a tomb discovered illegally built on the forbidden area was immediately dug up and the related people were severely punished. This indicates that the prohibition was effective until the mid-nineteenth century. The postscripts on the Ancestral Burial Ground on the Inwangsan Mountain document in detail Bak Gyeong-bin's efforts to obtain the land as a burial site. The help and connivance of villagers were necessary to use the burial site, probably because constructing tombs within the prohibited area was a burden on the family and villagers. Seokpajeong Pavilion by Yi Han-cheol (1808~1880), currently housed at the Los Angeles County Museum of Art, is another real scenery landscape in the format of a folding screen that is contemporaneous and comparable with Ancestral Burial Ground on the Inwangsan Mountain. In 1861 when Seokpajeong Pavilion was created, both Yi Han-cheol and Jo Jung-muk participated in the production of a portrait of King Cheoljong. Thus, it is highly probable that Jo Jung-muk may have observed the painting process of Yi's Seokpajeong Pavilion. A few years later, when Jo Jungmuk was commissioned to produce Ancestral Burial Ground on the Inwangsan Mountain, his experience with the impressive real scenery landscape of the Seokpajeong Pavilion screen could have been reflected in his work. The difference in the painting style between these two paintings is presumed to be a result of the tastes and purposes of the commissioners. Since Ancestral Burial Ground on the Inwangsan Mountain contains the multilayered structure of a real scenery landscape and family gravesite, it seems to have been perceived in myriad different ways depending on the viewer's level of knowledge, closeness to the commissioner, or viewing time. In the postscripts to the painting, the name and nickname of the tomb occupant as well as the place of his surname are not recorded. He is simply referred to as "Mister Bak." Biographical information about the commissioner Bak Gyeong-bin is also unavailable. However, given that his family did not enter government service, he is thought to have been a person of low standing who could not become a member of the ruling elite despite financial wherewithal. Moreover, it is hard to perceive Hong Seon-ju, who wrote the postscripts, as a member of the nobility. He might have been a low-level administrative official who belonged to the Gyeongajeon, as documented in the Seungjeongwon ilgi (Daily Records of Royal Secretariat of the Joseon Dynasty). Bak Gyeong-bin is presumed to have moved the tomb of his father to a propitious site and commissioned Ancestral Burial Ground on the Inwangsan Mountain to stress his filial piety, a conservative value, out of his desire to enter the upper class. However, Ancestral Burial Ground on the Inwangsan Mountain failed to live up to its original purpose and ended up as a contradictory image due to its multiple applications and the concern over the exposure of the violation of the prohibition on the construction of tombs on the prohibited area. Forty-seven years after its production, this screen became a part of the collection at the Royal Yi Household Museum with each panel being separated. This suggests that Bak Gyeong-bin's dream of bringing fortune and raising his family's social status by selecting a propitious gravesite did not come true.