• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.187-196
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• 2013

This study is focused on analyzing the deformation types of seaside armor stones based of field survey in order to establish the cause of abrasion following the deformation of seaside armor stones. 1. The deformation of seaside armor stone in saemangeum sea dike was classified as three different types: floating, deviation, and abrasion. 2. It was discovered that the stones floated to the extent of maximum 50 m, as the result of inspecting floating stones which were situated on different ten places. 3. The average number of deviation in the high ocean wave section was four times more than that in the ordinary ocean wave section, as a result of comparing the deviation number of the ordinary ocean wave section and that of the high ocean wave section for the purpose of inspecting the relation between the deviation of armor stones and the effects of ocean wave. 4. The angular shape of armor stones seen in the initial construction period has been abraded smoothly, as result of comparing of the shape change of armor stones for the purpose of inspecting abrasion state of seaside armor stones. 5. It was discovered that the abrasion of armor stone was severe in the section of many floating stones, as a result of analyzing the levels of abrasion and the cumulative sections of floating stones for the purpose of investigating the cause of abrasion.

• Journal of the Korean Society of Costume
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• v.59 no.5
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• pp.1-18
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• 2009

Due to the severe damages, it is very difficult to fathom out the original shape of the armor of Seong-ryong Ryu(1542-1607) right now. Ryu was a distinguished scholar official of his period, and his remaining armor has been designated as a National Treasure No. 460. This is a study of the types of the used scales, their positions used, the methods of their connections, and their hemmings, to figure out the original process of producing the armor. Based upon the research results, the remaining pieces of the armor are restored according to the discovered contemporary procedure of the armor. Then hypotheses are proposed for the three kinds of armor made up of long pieces, and three kinds of the armor of short pieces, and problems of the proposed hypotheses are considered for further studies. Hopefully this kind of approach shall serve as a ground stone for the better restorations of the scale armors of Joseon period in the future.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.4
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• pp.47-55
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• 2016

This study is on the stability re-evaluation of armor stones in saemangum seadike according to recently increased sea-level and frequent high wave incoming and the results are in the following. The field inspection of armor stones in the seadike revealed that damages of armor stones have been caused by higher waves than designed waves and that the reconstruction of armor stones and concrete grouting method have been used as the reinforcement work. The result of numerical simulation of wave channel conducted to estimate the safety weight of armor stones influenced by flows revealed that the safety weight of armor stones in the seadike No.4 was estimated as 5.47 tons by using the Isbash method, which is about 122 % more than 4.49 tons estimated by using Van der Meer method. Therefore, in designing armor stones which can be influenced by high waves such as the case of Saemangum seadike, it is necessary to apply the safety weight method of armor stones, based on the Isbash method, which produced the significant figures among the safety weight methods using flows as well as the safety weight method using high waves based on the Hudson method.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.5
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• pp.19-27
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• 2015

The results of Saemangeum seadike field inspection and material testing of armor stones in order to analyze causes of abrasion according to material characteristics of seaside armor stones in Saemangeum seadike are in the following: 1. The armor stones in Saemangeum seadike have been constructed by using internal stones (mainly, sinsi stones) and external stones, which had less strength (77.3 %) and more abrasion rate (133.3 %) compared with sinsi stones. 2. The compressive strength and abrasion rate were compared between ordinary wave section and high wave section for the purpose of analyzing the influence of waves. In compressive strength, sinsi stones were 4.0 % stronger and external stones were 0.6 % stronger in ordinary wave section than those of high wave section in average. In the case of abrasion rate, sinsi stones were 3.0 % higher and external stones were 8.2 % higher in the high wave section than those in the ordinary section. 3. The result of comparing compressive strength according to a zone is that the compressive strength in the Intertidal area was less strong in most of the zones. 4. Considering that deviated stones are moving around over the surface of armor stones in situ, it is important to compare material characteristics. So the comparison test about this factor showed that deviated sinsi stones were stronger than armor stones in situ in terms of compressive strength and resistance to abrasion. Based on these results, abraded armor stones may have resulted from their durability. Therefore it is assumed that armor stones are likely to be abraded when deviated stones which are more durable are moving around over armor stones which are less durable.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.81.1-81
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• 2002

$\textbullet$ This paper presents a study on the development of a walking robot for an armor-stone work of the breakwater construction. The armor-stone work is putting stones about 0.3 ∼ 2m3 on the surface of the breakwater to prevent it from waving. $\textbullet$ This work has been done manually, and its process plan is uncertain by effects of the weather, wave and tide of sea. Therefore the constructional cost is considered to be wasteful $\textbullet$ Working in underwater as well as on land for human workers causes the accident and caisson disease, so it is necessary to replace the process to be mechanized. $\textbullet$ The basic requirements of the robot for mechanizing are as follows : 1) To have a large...

• Journal of the Korean Society of Costume
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• v.30
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• pp.183-200
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• 1996

The purpose of this study is to examine the custume of Stone statues in roylal tombs and graves in Shilla dynasty. Stone statues in royal tombs and graves in Shilla dynasty. Stone statues in royal tombs and graves are divided into statues of the twelve horary signs(十二支像) and stone figure of a man(石人像). The results are as follows. 1. Statues of the twelve horary signs are found eleven in royal tombs and graves. First statues of the twelve horary signs in assumed Shinmunwangrung(推定神文王陵) wear long robe(長袍) pants(袴) skirt(裙) It says that the costume element of Shilla and the costume element of Tang are mixed. But statues of the twelve horary signs was developed as a tutelary god. Statues of the twelve horary signs in Kimyoushinmyo(金庾信墓) wear jacket pants(袴) instead of long robe(長袍). Also as attaching instead of long robe. Also as attaching other color cloth in collar of jacket or not they are showing dress of mulitary officer. next statues of the twelve horary signs in Hondokwangrung(憲德王陵) wear long robe(長袍) pants(袴). it says that they imitate assumed Shinmunwangrung(推定神文王陵) Kimyoushinmyo(金庾信墓). And statues of the twelve horary signs in the rest of royal tombs and graves put on decorative armor. 2. Stone figure of a man are found is Song-dokwangrung(聖德王陵) Wonsongwangrung(元聖王陵), Hungdokwangrung(興德王陵) and divided into two types. Type 1 wear long robe(長袍) and Yangdang(裲襠). They stend for the best dress uniform of military officer. Type 2 wear Danreong(團領) with side slash. They stend for common soldier.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1781-1786
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• 2003

This research develops a robot as the device which constructs underwater harbour. This construction is to build a breakwater, which is dangerous and difficult. The hydraulic parallel mechanism-typed robot is developed to mechanize the construction by operating of a stoneworker (or diver) through a joystick. The six-dof robot is able to carry 2-3 tons' heavy stone and put it on the surface of breakwater. This paper presents the mechanical design of a miniature robot, its control and application for the breakwater construction.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.186-195
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• 2001

The purpose of this study is to develop the time-dependent, one-dimensional numerical model on the interaction between irregular waves and two-layer permeable coastal structures, by extending and modifying the numerical model PBREAK(Wurjanto and Kobayashi, 1992) which is applicable only to one-layer permeable coastal structures. The two-layer permeable coastal structure consists of two permeable underlayers with different permeable media resting on an impermeable slope and an armor layer covering the permeable underlayer. The numerical model of this study simulates the wave over rough permeable underlayer of arbitrary geometry as well as the waves inside two-permeable underlayers of arbitrary thickness for specified normally-incident irregular waves. The utility of the numerical model is founded from comparing with PBREAK and the four hydraulic model tests under irregular waves. The sensitivities of computed results according to typical parameters(porosity, stone diameter, horizontal width of the permeable underlayer) and major factors(friction factor of primary armor layer etc.) discussed.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.443-445
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• 2008

Determination of allowable overtopping rate for coastal structure is a key point to determine the application of background of coastal structure while considering safety and economic efficiency. Thus, the accurate estimation of overtopping rate against coastal structure is essential. In general, estimation of overtopping against the coastal structure is based on an empirical formula or hydraulic experiment. In this study, we investigate the behavior of overtopping for rubble mound coastal structure with rubble armor stone and wave dissipating block using hydraulics experiment, and domestic or foreign design standard.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.3
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• pp.299-308
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• 2011

In this study, we develop a pressure observer to measure the cylinder length of a harbor-construction robot. For the robot control, sensors are required to measure the length of a hydraulic cylinder. The cylinder-position sensor is relatively expensive when the operating environment prohibits external approaches for the measurement of the cylinder position. LVDT or linear scales are usually mounted on the outside of the cylinder, which causes poor durability on a construction site. We use a pressure sensor to indirectly estimate the length of the cylinder. The pressure sensor is mounted inside a hydraulic valve box so that it is protected by the box and easy to waterproof for an underwater robot. By treating oil as a compressible fluid, we derive the nonlinear pressure dynamics as a function of the cylinder position, velocity, and pressure. The recursive least squares (RLS) algorithm is applied to identify the dynamic parameters, and the pressure observer estimates the cylinder position through the pressure acting on the head and the rod of the hydraulic cylinder. The position accuracy is relatively low, but it is acceptable for a construction robot that handles large armor stones.