• Journal of architectural history
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• v.17 no.5
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• pp.7-22
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• 2008

The purpose of this study is to examine the function of wall posts in pit-houses in the Bronze Age, in the Kyung-nam Province. Wall posts were found as post-holes, created after wooden posts had decayed. In this research, the role of wall posts is newly defined from the perspective of a construction engineering. While existing studies in archaeology regard wall posts as sub-posts that support the roof of a pit-house, this study views wall posts as piles installed to support the soil wall, not as sub-posts. Based on the existing reports on excavation in prehistoric settlement sites by archaeologists, the study examines the remnants of the wall posts and remains after a fire. The main findings of this study are threefold. First, the wall posts were installed not as posts but as piles, cut sharply and hammered along the building lines of a pit-house. Second, wall piles were used to support the walls during earthwork, such as excavating and banking for low ground, mostly because a large amount of soil is often lost during the process. Third, wall piles were used as post piles of retaining walls that enabled the installation of transverse wall panels, which were used to prevent the soil loss.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.677-688
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• 2017

In order to solve the undetected probability of multiple targets in ultra-wideband (UWB) through-the-wall radar imaging (TWRI), a time-delay and amplitude modified back projection (BP) algorithm is proposed. The refraction point is found by Fermat's principle in the presence of a wall, and the time-delay is correctly compensated. On this basis, transmission loss of the electromagnetic wave, the absorption loss of the refraction wave, and the diffusion loss of the spherical wave are analyzed in detail. Amplitude compensation is deduced and tested on a model with a single-layer wall. The simulating results by finite difference time domain (FDTD) show that it is effective in increasing the scattering intensity of the targets behind the wall. Compensation for the diffusion loss in the spherical wave also plays a main role. Additionally, the two-layer wall model is simulated. Then, the calculating time and the imaging quality are compared between a single-layer wall model and a two-layer wall model. The results illustrate the performance of the time-delay and amplitude-modified BP algorithm with multiple targets and multiple-layer walls of UWB TWRI.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.253-259
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• 2002

Micro cell structures with high aspect ratio were fabricated by injection molding method. The mold inserts had dimension $1.9cm\times8.3cm$ composed of a lot of micro posts and were fabricated by LIGA process. The size of the micro posts was $157{\mu}m\times157{\mu}m\times500{\mu}m$ and the gaps between two adjacent posts were $50{\mu}m$. Using Polymethylmethacrylate (PMMA) injection molding was performed. The key experimental variables were temperature, pressure, and time. By controlling these, good shaped mim cell structures with $50{\mu}m$ in wall thickness and $500{\mu}m$ in depth were obtained. In order to understand micro molding mechanism, shape changes of molded PMMA were studied with experimental variables. And the durability of mold insert was investigated, too. The results show that the most important factor in molding processes was the mold temperature that is closely related to the filling of the melt into the micro cavity. And the holding time before cooling showed a great effect on the quality of molded PMMA.

• The Journal of Korean Academy of Prosthodontics
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• v.24 no.1
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• pp.55-65
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• 1986

An in vitro study was performed to evaluate adaptation of custom direct, custom indirect, and prefabricated post system on 15 extracted upper central incisors. 15 specimens were prepared and equally devided into 3 groups under random sampling. Each group of 5 cast posts was made with custom direct, custom indirect, and prefabricated post core method. Gap between inner wall of the dentin and outer wall of the cast post was measured on electron microphotographic prints at x500 magnification. The result were as follows ; 1. No significant difference of adaptation at cervical portion was found between each method. 2. Prefabricated post core method had poor adaptation compared with other methods. 3. Even distribution of adaptation was found in custom direct method between each portion. 4. Prefabricated post core method showed remarkable difference in adaptation between each portion.

• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.347-372
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• 2012

This paper explores the current condition of facebook pages in order to provide university libraries with practical ideas in using facebook services. A total of 20 facebook pages of 20 selected Korean and USA university libraries were examined and analyzed in various ways. The research questions for this study are: (1) how well do library operate the facebook page? (2) what are the category and nature of wall posts of library facebook pages. To get the answers to this questions, various checkpoints are developed and applied. The most significant findings are that there are a quite different data of operation and there are similar patterns of posts communication to the Korean and USA university library pages.

• Journal of the Korean Society of Safety
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• v.5 no.2
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• pp.66-75
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• 1990

This study is conducted to establish the structural standard of tube and coupler scaffold which is suitable for our present stuation through the comparison analysis for domestic and foreign standards as well as measurement of field survey. The results of this study are as follows ： 1) The load is classified by three categories, light-duty(equal and lower than 150kg/m$^2$), medium-duty(150-250 kg/m$^2$), heavy-duty(250-350kg/m$^2$), and the equivalent horizontal length of side posts is each, 1.5-1.8m, 1.2-1.5m, equal and lower than 1.2m, and the equivalent horizontal length between front and rear posts is each 1.2-1.5m, 0.9-1.2m, equal and lower thatn 0.9m, in accordance with the load classification. 2) The height between upper and lower runner is equal and lower than 1.5m, and the brace across the width of scaffold should be installed within 15m in horizontal direction at 45 degree angle. 3) The entire scaffold should be securely tied to the wall of permanent structure with uslng anchor and bolt at intervals not to exceed 6m in case of non-connection and 4.5m in case of connection in both horizontal and vertical direction. 4) The post should be installed on the sound foundation tied to lumber footing with using base plate, and standard platform plank should be produced in the factory and widely used in the construction field.

• Geomechanics and Engineering
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• v.31 no.5
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• pp.489-503
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• 2022

A 1257-m-long irregular deep foundation pit located in the central of Nanjing, China was constructed using the combined full-width and half-width top-down method. Based on the long-term field monitoring data, this study analyzed the evolution characteristics of the vertical movement of the columns, internal force of the struts, and axial force of the structural beam and slab. The relevance of the three mentioned above and their relationship with the excavation process, structural system, and geological conditions were also investigated. The results showed that the column uplift was within the range of 0.08% to 0.22% of the excavation depth, and the embedded depth ratio of the diaphragm wall and the bottom heave affected significantly on the column uplift. The differential settlement between the column and diaphragm wall remained unchanged after the base slab was cast. The final settlement of the diaphragm wall was twice the column uplift. The internal force of the struts did not varied monotonically but was related to numerous factors such as the excavation depth, number of struts, and environmental conditions. Additionally, the dynamic force and deformation of the columns, beams, and slabs were analyzed to investigate the inherent relationship and variation patterns of the responses of different parts of the structure.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.102-115
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• 2014

The stamped earth method is a typical ancient engineering technique which consists of in-filling wooden frame with layers of stamped earth or sand. This method has been universally used to construct earthen walls and buildings, etc. The purpose of this article is to understand the construction method and principles of the stamped earthen wall through analysis of various construction techniques of Pungnaptoseong Fortress(Earthen Fortification in Pungnap-dong). First of all, the ground was leveled and the foundations for the construction of the earthen wall were laid. The underground foundation of the earthen walls was usually constructed by digging into the ground and then in-filling this space with layers of mud clay. Occasionally wooden posts or paving stones which may have been used to reinforce the soft ground were driven in. The method of adding layers of stamped earth at an oblique angle to either side of a central wall is the most characteristic feature of Pungnaptoseong Fortress. Even though the traces of fixing posts, boards, and the hardening of earth - all signatures of the stamped earth technique - have not been identified, evidence of a wooden frame has been found. It has also been observed that this section was constructed by including layers of mud clay and organic remains such as leaves and twigs in order to strengthen the adhesiveness of the structures. The outer part of the central wall was constructed by the anti-slope stamped earth technique to protect central wall. In addition a final layer of paved stones was added to the upper part of the wall. These stone layers and the stone wall were constructed in order to prevent the loss of the earthen wall and to discharge and drain water. Meanwhile, the technique of cementing with fire was used to control damp and remove water in stamped earth. It can not be said at present that the stamped earth method has been confirmed as the typical construction method of Korean ancient earthen walls. If we make a comparative study of the evidence of the stamped earth technique at Pungnaptoseong Fortress with other archeological sites, progress will be made in the investigation of the construction method and principles of stamped earthen wall.

• Journal of the Korean Wood Science and Technology
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• v.39 no.2
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• pp.140-147
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• 2011

The strength properties of wooden retaining wall which was made with pitch pine were evaluated. Wooden retaining wall was made with diameter 90 mm of pitch pine round posts treated with CUAZ-2 (Copper Azole). The length of the front stretcher of the retaining wall was 3,000 mm. The distance between the headers (the notched member) is 1,000 mm in center and is 900 mm in side. There were connections every 2,000 mm because actually the length of stretcher is limited in the retaining wall. The strength test was carried out according to connection type because the section between stretchers can act as a defect. A result of the strength test according to connection type confirms that connection does not act as defect because the strength of retaining wall in single stretcher is similar to that in the section between stretchers. The strength test of the wooden retaining wall was carried out in 5 types according to the condition of the base section. When the upper soil pressure was 9.8 kN/$m^2$, the maximum load of the retaining wall fixing the front foundation shows higher values than those of others. But the total deformation is lower in the retaining wall not to fix a base section than in that to fix a base section. It is thought that the retaining wall not to fix a base section shows low value because the deformation is distributed throughout the retaining wall and it is confirmed that the soil pressure affects supporting the structure because the deformation of the retaining wall under low pressure is 3~4 fold higher than those of others. The failure mode of the retaining wall is the overturning type because the high section is deformed. Mostly, the failure mode is the separation of the header in the notched section.

• Journal of Public Diplomacy
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• v.1 no.2
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• pp.49-74
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• 2021

In this paper, I applied grounded theory in exploring how Twitter became the battlefield for China's public diplomacy campaign. China's new move to global social media platforms, such as Twitter and Facebook, has been a controversial strategy in public diplomacy. This study analyzes Chinese Foreign Spokesperson Zhao Lijian's Twitter posts and comments. It models China's recent diplomatic move to Twitter as a "war of words" model, with features including "leadership," "polarization," and "aggression," while exerting possible effects as "resistance," "hatred," and "sarcasm" to the global community. Our findings show that by failing to gage public opinion and promote the country's positive image, China's current digital diplomacy strategy reflected by Zhao Lijian's tweets has instead constructed a polarized political public sphere, contradictory to the country's promoted "shared human destiny." The "war of words" model extends our understanding of China's new digital diplomacy move as a hybrid of state propaganda and self-performance. Such a strategy could spread hate speech and accelerate political polarization in cyberspace, despite improvements to China's homogenous network building on Twitter.