• Conservation Science in Museum
• /
• v.22
• /
• pp.1-14
• /
• 2019

The excavation of the south mound of Hwangnamdaechong Tomb in Gyeongju has yielded diverse types of shell artifacts. Among the them, this paper investigated fragments of shell ornaments with gilt-bronze frames, the use of which has not been identified. It was revealed that the artifacts are in fact nautilus cups, which had never been found previously in excavations in Korea. A nautilus is a species marine mollusk known to be the closest to prehistoric ammonites. It has brown stripes on the surface of the shell and septa inside, and a siphuncle penetrating to the center of the septa. It is known that nautilus cups were made and used in China, but only three examples have thus far been identified. These surviving cups have metal ornaments and are dated to the Western and Eastern Jin periods of China. No nautilus cups have been found in Japan, and the shell ornaments investigated in this study were determined to be the first nautilus cups ever found in Korea. Nautilus cups are mentioned in ancient documents and literature, including in poems by the Tang Dynasty poet Li Bai and in Joseon-period documents. This paper presents the biological characteristics of nautili, cases of excavation of nautilus cups outside Korea, and findings from the basic research of the nautilus cup from Hwangnamdaechong Tomb.

• Journal of Ocean Engineering and Technology
• /
• v.16 no.1
• /
• pp.71-75
• /
• 2002

대형 시추구조물의 건조는 보통 드라이도크에서 하거나, 해양에서 선체와 데크를 접합하는 방법을 사용한다. 그러나 적당한 해양 접합장소가 없거나 드라이도크의 공간부족으로 현대중공업에서는 드라이도크나 해양에서의 접합건조 대신 부유식 시추구조물을 지상에서 조립하는 방법을 채택하게 되었다. 현대중공업에서는 세 가지 단계를 통해 지상 데크조립을 수행하였다. 첫 번째는 네 개의 철골구조 리프팅타워 상에서 유압리프팅시스템을 이용하여 데크를 지상으로부터 38m 들어올린다. 두 번째는 마찰을 줄이기 위해 윤활제가 칠해진 합성 플라스틱으로 싸인 미끄럼틀(Skidway)을 이용하여 두 개의 6000톤 짜리 하부구조를 데크 아래로 끌어 들인다. 마지막 단계로 데크와 하부구조를 단단히 결합시킨다. 이 과정에 2주일이 소요되었으며 일련의 작업을 거쳐 중량 25,500톤급의 Deepwater Nautilus (RBS-8M) 시추선을 무사히 바다 위로 인도하였다. RBS-8M의 데크결합에 Super Lift를 적용하여 성공시킨 사례를 통해 현대중공업의 초대형 시추구조물 건조방식이 이상적이고, 작업 공기나 원가 측면에서 우위가 있음을 시사하고 있으며 이렇게 건조작업의 대부분을 지상에서 수행한 과정을 통해 작업관리, 품질관리, 일정관리에도 좋은 결과를 가져올 수 있었다.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.26 no.3
• /
• pp.308-314
• /
• 2016

This paper proposes design guidances for noise reduction of a bank teller cash recycler(TCR). The operating noise of a TCR is required to be reduced because it bothers bank tellers and customers. The operating noise from a TCR is measured and the most influential driving system is examined. To find the main sources of the noise, the frequency spectra are analyzed by comparing with excitation frequencies of the driving system. From the analysis results, we reveals that the main sources of the noise are gear mesh frequency of a certain gear train and its side band frequencies, which is attributed by vulnerable support condition. Consequently, to reduce the operating noise, the structural modification for the gear train support is suggested and its effectiveness for the noise reduction is confirmed experimentally.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.900-905
• /
• 2004

Development of color printer, postal classification machine, ATM and so on requires higher moving performance of the flat belt. Skew of the flat belt running over misaligned roller has a bad effect on performances of media transport. The vibration of loose side of belt causes the escape of the belt from roller and the drop of velocity of driven roller after the start of driving roller revolution. The skew of flat belt is investigated by FEM and dynamic simulation. FEM results show parameters which affect the skew of belt and match with dynamic results qualitatively. The shape of loose side of belt can be found by dynamic simulation. Increase of the acceleration time and initial tension have diminished the unstable movement of the loose side of belt.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.1
• /
• pp.73-79
• /
• 2012

Kiosks are widely used in drive-thru systems in parking lots or on the highway to provide various services to drivers. However, the driver must stop at an exact location to access the kiosk, since its panel is fixed. In order to improve the kiosk accessibility, in this study we developed a manipulator that can adjust the position of the kiosk panel. The number of active joints was minimized to lower the cost, whereas a parallelogram mechanism and passive joints were adopted to increase its convenience for the users. Furthermore, a safety mechanism using springs and a cam was designed to ensure the safety of the user in the case of an emergency. The performance of the position controller and the safety mechanism were verified through various tests. In addition, the proposed collision reaction strategy improved the safety performance of the kiosk system.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1125-1130
• /
• 2005

This paper presents a method for inter-sheet spacing control in a flexible media handling device. In order to verify the performance of inter-sheet spacing control by experiment, system of section structure is introduced in the first place. In the introduced system, each section is driven by different servo motor for independent section freedom. And suitable inter-sheet spacing control algorithm that is more optimal than conventional inter-sheet spacing control algorithm is proposed. Finally experiments are performed to confirm the performance of inter-sheet spacing control. And two inter-sheet spacing control algorithms, conventional and proposed, are compared with each other.

• Journal of Wellness
• /
• v.7 no.4
• /
• pp.187-199
• /
• 2012

The purpose of this review was to introduce a new training concept as pneumatic training method and how to apply the principles. Uses the new resistance, especially air powered that invisible, intangible, along with training on how to contribute to broadening their horizons, while attempts have been passed. Provide transition training methods in accordance with the trend of the times, and why these changes may be in the form of outside-free for theoretical consideration. From weight resistance, hydraulic, isokinetic exercise, and to pneumatic training why justification should apply for these training methods are presented also suggested the superiority of pneumatic training. In the near future, newly developed training method will be appear. In conclusion, it will be contribute to sports by concerning and applications to cutting edge training

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.13 no.3
• /
• pp.271-279
• /
• 2008

Polymetallic sulphides means hydrothermally formed deposits of sulphide minerals which contain concentrations of metals including, inter alia, copper, lead, zinc, gold and silver. Nautilus is the first company to commercially explore the seafloor polymetallic sulphide deposits. The Company holds exploration licences and exploration applications for more than 370,000 $km^2$ in the jurisdictional seas of Papua New Guinea, Fiji, Tonga, the Solomon Islands and New Zealand along the western Pacific Ocean's Rim of Fire. Neptune Minerals is also a leading explorer and developer in this field, with exploration licences awarded totalling more than 270,000 $km^2$ in the territorial seas or EEZ of New Zealand, Papua New Guinea and the Federated States of Micronesia. These two companies now carry out the most active investment activities for seafloor polymetallic sulphide deposits with a goal of commercial production by 2010. China and Japan carry out exploration activities for the seafloor polymetallic sulphide deposits to secure supplies of strategic metals. China carries out national R&D projects relating to deep sea mineral resources in the world ocean through China Ocean Mineral Resources R&D Association(COMRA). And Japan investigates her own EEZ for exploration of the seafloor polymetallic sulphide deposits. In consideration of aforementioned international activities of coastal nations as well as private companies for exploring the sulphide deposits, Korea shall prepare strategic plans : First, consolidation of the authorities concerned and legislative support; second, determination of main entity of the project; third, securing government's decisive investment of sufficient budget; and lastly, establishment of the mid, long-term plan for development of seafloor polymetallic sulphides deposits.