• 한국연안방재학회지
• /
• 제5권4호
• /
• pp.203-210
• /
• 2018

It is generally known that submerged breakwaters can reduce the incoming wave energy without disturbing the beach scenery. However, a submerged breakwater is also able to cause a setup of the sea level in the protected area which is also called as water piling-up. Since the piling-up can result in longshore currents, sediment transports, and unexpected beach erosion, understanding about the piling-up process is required prior to designing the nearshore structures. In this study, the water piling-up behind a submerged breakwater is assessed in the time of storm events. For the study area, Anmok beach in Gyeonso-dong, Gangwon-do is selected. 1-year, 5-year, 10-year, and 50-year return-values were derived from Peaks-Over-Threshold(POT) method and those are applied as offshore boundary conditions for the numerical simulation. The numerical results of the piling-up were assessed with regard to the wave steepness and the height of the submerged breakwater. With increase of both significant wave height and the height of the submerged breakwater, the piling-up parameter is also increased which can lead to erosion of dry beach behind the structure.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1367-1372
• /
• 2007

Over the past decade, many computational researches have been performed to investigate quantitative relationships between load-displacement and material properties. But piling-up which causes errors to estimate mechanical material properties remains the most significant unresolved issue in nano-indentation test. This study has estimated quantitative aspects of the effects of material properties, especially work hardening exponent, on piling up/sinking in response of various materials. Using FE Analysis, piling up/sinking in response when material is indented by sharp indenter is investigated to evaluate the effects of material properties. From the FE analysis result, quantitative relationships between piling up/sinking in height and material properties is assessed using dimensional analysis which is used to define scaling variables and universal functions. And nano-indentaion test is performed to verify this relation on various materials. From the result of comparison with prediction from dimensional function and experiment, the work hardening exponent was found to have greater influence on the piling up/sinking in height during the nano-indentation than other material properties, such as elastic modulus and yield stress.

• Journal of Advanced Marine Engineering and Technology
• /
• 제33권5호
• /
• pp.762-769
• /
• 2009

A canoe is one of the most popular boats in leisure on the water. Generally canoe has been built by good wooden strips. And canoe built by FRP is used for business recently. But by the users' demands for good quality and the restriction to environmental pollution the wooden canoes are required for personal and canoe building business. The modern wooden canoes were built by the strip construction method are used typically. However it is not suitable for the mass productivity requires effective resource operations and managements of men, materials, times, and price. On this paper the new construction method, called the piling-up laminated construction method, is studied to building a canoe using the piling-up with the laminated wooden plates gives more productivity than the others. First a canoe with various curved surfaces is designed from 3D design system. And the hull of canoe model is divided horizontally to generating the laminated plates that will be converting real wooden plates available from the market and will be routed by the manufacturing machine. After the simulating and analyzing of piling-up with the laminated plates, the canoe is building with less times, less men, less resources, and lower price than other method, avoid of the requirements of additional building tools. On the next paper the constructing of a real canoe using the manufactured wooden plates will be studied.

• 한국가구학회지
• /
• 제18권4호
• /
• pp.296-306
• /
• 2007

As life style changes, the demand for stacking chairs are increasing as the use of event halls or outside furniture where people gather in crowd is increasing. Early stacking chairs were mainly made to pile up a great amount and store, but in modern days it also has a decorative purpose. Besides, the development of various new materials and applied technology of furniture manufacture, the structure and design of stacking chair is becoming more interesting. Basically, according to the structure of the leg, the form and method of piling up is decided. The structure of the leg means the location of the leg connected to the seat, and according to the location, it can be piled up as upper, front, or rotational type. Such is the way how stacking chairs are classified according to the location of the leg, with its basis; the structure of stacking chair is reviewed. Now, chair for piling up is overcoming its simple function, which aesthetic beauty or arrangement of color after piling up is being considered. Also, according to storing, moving, and the place of use, various designs are demanded. As people's interest in stacking chair is increasing, various research regarding design should continue.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
• /
• pp.489-497
• /
• 2000

Since Chinese cabbages weigh 3 to 5kgf and are big in size at the time of harvest, handling operations such as harvesting, loading and unloading including transportation require the highest labor demand among all other cultivation processes. Recently, though several cabbage harvesters were developed in Japan and Europe, those harvesters were not suitable for Chinese cabbages cultivated in Korea because of the size and shape. The cabbage harvester is almost meaningless without any proper cabbage piling and pallet unloading mechanism. Most harvesters developed so far adopted a sort of slide and free falling way in collecting cabbages into the pallet. Three or four labors are usually required for cleaning incoming cabbages and loading those in the pallet. Because of the required time for piling cabbages without severe damage and the required space capacity to carry empty and loaded pallets, harvesting speed should be adjusted in accordance with time required for consecutive operations. Up to now, any automatic or semi-automatic collecting device has not been developed in the world to pile cabbages on the layer one by one into the pallet in the ordered way with little damage and to unload pallet from the harvester continuously during the harvest process. To compromise system expenses and function, Semi-automatic cabbage piling and pallet unloading mechanism was devised and it required one labor. The foldable mesh pallet with a size of 1050mm x 1050mm x 1000mm and holding capacity of around 70 cabbages was utilized. The prototype for piling and unloading mechanism was composed of three parts such as feeding device, automatic piling device with retractable bellows, and pallet unloading device. Prior to developing the prototype, the geometric properties and the amount of the damage of the cabbage caused during the piling operation were investigated. Considering the height of the pallet, a series of cabbage carrying plates were mounted to the bracket chain to lift and to carry cabbages to the loading device. Indoor laboratory experiments showed that the cabbage carrying chain conveyor worked successfully. Considering the conveying speed 0.46m/sec of the pull up belt from the cabbages on the ground, the speed of cabbage carrying chain conveyor worked property in the range of 0.26m/sec to 0.36m/sec. The system allowed the operator to modify the position of cabbage slightly. Overall system worked successfully resulting into almost same capacity without severe damage to the cabbage as human did.

• 유공압시스템학회논문집
• /
• 제5권3호
• /
• pp.9-14
• /
• 2008

The application of an excavator can be expanded to various works through change of end-effector. In this paper, a gripper, which can pick up and rotate a fixed formal stone, was developed. The device was designed and produced to pick up and rotate a stone for an excavator. The maximum weight of stone was computed to prevent from reversal in according to each displacement of attachments. The necessary force of a hydraulic cylinder to grip a stone was obtained by simulation.

• Geomechanics and Engineering
• /
• 제34권4호
• /
• pp.397-408
• /
• 2023

Pipe pile walls are commonly used as retaining structures for excavation projects, particularly in densely populated coastal cities such as Hong Kong. Pipe pile walls are preferred in reclaimed land due to their cost-effectiveness and convenience for installation. However, the pre-bored piling techniques used to install pipe piles can cause significant ground disturbance, posing risks to nearby sensitive structures. This study reports a well-documented case history in a reclamation site, and it was found that pipe piling could induce ground settlement of up to 100 mm. Statutory design submissions in Hong Kong typically specify a ground settlement alarm level of 10 mm, which is significantly lower than the actual settlement observed in this study. In addition, lateral soil movement of approximately 70 mm was detected in the marine deposit. The lateral soil displacement in the marine deposit was found to be up to 3.4 and 3.1 times that of sand fill and CDG, respectively, mainly due to the relatively low stiffness of the marine deposit. Based on the monitoring data and site-investigation data, a 3D numerical analysis was established to back-analyze soil movements due to the installation of the pipe pile wall. The comparison between measured and computed results indicates that the equivalent ground loss ratio is 20%, 40%, and 20% for the fill, marine deposit and CDG, respectively. The maximum ground settlement increases with an increase in the ground loss ratio of the marine deposit, whereas the associated influence radius remains stationary at 1.2 times the pipe pile wall depth (H). The maximum ground settlement increases rapidly when the thickness of marine deposit is less than 0.32H, particularly for the ground loss ratio of larger than 40%. This study provides new insights into the pipe piling construction in reclamation sites.

• 한국조경학회지
• /
• 제38권3호
• /
• pp.83-97
• /
• 2010

석가산은 한국 전통조경의 구심적 구성요소로서 고려시대와 조선시대 전통 석경관의 한 축을 이루며 발달하여 왔으나, 현대에 와서 그 맥이 단절되었다. 고려 중기 모사적 축경식에서 출발한 첩석 석가산이 점차 사의적 석가산으로 발달, 변천하면서 전통 석경관 문화의 새로운 전환기를 맞이하였다. 한국의 전통 석가산은 중국의 주변경관을 압도하는 거대한 석가산과는 달리 소동산형으로 주변에 조화되게 한국적 석가산 문화를 구축하였다. 이 연구는 고문헌과 현장유적을 근거로 한 실증적 조사로서 석가산의 유형과 발달양상을 구명하고자 하였으며, 조사결과 석가산은 괴석을 쌓아올린 첩석형을 기본 골격으로 지변 첩석형, 첩석형, 지중형, 치석형, 분형 등 다섯 유형이 발달해온 것으로 나타났다. 이 중 석가산에 물이 흐르는 지변 첩석형 석가산은 고려 중기 도입된 이후부터 조선 후기까지 성행되어온 대표적 유형이다. 이러한 연구는 석가산의 조경문화사적 가치와 정체성을 회복하여 단절되어 온 석가산의 전통의 맥을 계승하고 발전시키는데 토대가 될 것으로 기대한다.

• 복식
• /
• 제59권5호
• /
• pp.41-52
• /
• 2009

In contemporary art, soft materials are used in various forms and ways as a medium expressing contingency beyond a simple nature of materials. In the late 1960's, the appearance of soft sculpture as a refusal of the stereotyped 'Erection' characteristic of traditional sculpture served as an opportunity for more attention to soft materials. Fashion is the reflection of age, and the mirror of society, culture and arts. In other words, soft sculpture and fashion are artistic behaviors in the same context, which have neither been fixed nor erected. This study finds its significance in analyzing correlation between soft sculpture and fashion, and the importance of contingency as artistic expression means in this age when boundaries between genres are obscure, and artistic values are given to fashion. By doing so, it aims to present the direction toward which fashion should face in the future, establishing a new aesthetic consciousness with which more creative and various expressions are available in fashion as well. This study presented as its theoretical background the concept of soft sculpture affected by Marcel Duchamp among representative examples of the contingency that started to appear in art starting in the early 20th century. It also analyzed the soft sculpture appeared in 1960s and the expression methods and features of contingency appeared in fashion after late 1990s through a new approach of piling up, hanging up, and tying, three categories classified by Maurice $Fr{\acute{e}}churet$. Common features of the contingency expressed in soft sculpture and fashion were derived in the analysis, which are intensive effects of energy, values given to physical properties themselves, and esthetics of anti-form.

• 한국지반공학회논문집
• /
• 제19권4호
• /
• pp.235-246
• /
• 2003

국내의 경우 이 등(1994)의 연구를 시작으로 국지 현장별로 타입말뚝의 지지력 증가효과에 대한 사례연구들이 있었다. 그러나 충분한 시험자료를 바탕으로 한 지지력 증가효과에 대한 전반적인 검토는 아직 미흡한 실정이고, 또한 지지력 증가효과에 지반조건 및 말뚝의 형상이 미치는 영향에 대해서는 아직 보고 된 바 없다. 타입말뚝의 지지력 증가효과를 실무적으로 이용하기 위해서는 현장에서 실구조물에 적용된 말뚝에 대한 시험자료의 분석을 실시하는 것이 필요하다. 본 연구에서는 말뚝기초의 설계 및 향후 사질토에서의 지지력 증가효과 등의 연구를 위한 기본 자료로 활용하기 위해 실구조물에 적용되는 다양한 시험말뚝의 시공과 동재하시험 자료 분석을 통해 지지력 증가효과에 대한 현상을 알아보았다. 말뚝의 동재하시험의 분석 결과, 말뚝지지력의 증가는 토질별로도 영향을 받지만 조성이력에도 영향을 받는 것으로 분석되었으며, 특히 사질토에도 상당한 지지력 증가효과가 나타났다. 이러한 말뚝의 지지력의 증가는 주로 주면부에서 발생하였으며, 선단형상에 따른 지지력 증가효과는 점성토에서는 폐단말뚝이 크고, 사질토에서는 개단말뚝이 큰 것으로 나타났다.