• Title/Summary/Keyword: Stone tools

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A Study on the Material Characteristics of Stone Tools Excavated from the Remain Point of Paleolithic Age in Osong Site, Cheongju

  • Kim, Jae Hwan;Han, Min Su
    • Journal of Conservation Science
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    • v.35 no.1
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    • pp.41-49
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    • 2019
  • This study analyzes the material characteristics of stone tools of the Paleolithic period excavated from the Osong site, located at the project site for the creation of the Osong 2nd Life Science Complex, and estimates the provenance of the stone materials. Because the stones had been buried for a long time, their surfaces had become heavily weathered yellow or yellowish-brown, and the magnetic susceptibility values varied from 0 to 15(${\times}10^{-3}SI$). The excavated stone tools were rocks with various magnetic susceptibility values that could not be specified. Five stone tools subjected to destructive analysis were divided into two groups, one with a value of 1-3(${\times}10^{-3}SI$) and the other with a value of 5-9(${\times}10^{-3}SI$), both based on visible characteristics. The results of the thin-section analysis showed that most of the stone tools were basaltic rocks comprising plagioclase, quartz, and pyroxene, and some had iron content as high as 20 wt.%. These findings and the present geological map suggest that the stone tools were not made from the surrounding rocks because there are no areas containing basaltic rocks surrounding Bongsan-ri in Osong-eup. Andesite and tuff are distributed along with basaltic rocks in the Doan-myeon area in Jeongpyeong-gun, Chungcheongbuk-do Province, but the distance from the excavation site is too far. To determine whether this region is actually related to the provenance of the raw rock, it is necessary to conduct additional field surveys and comprehensive and precise analyses.

Archeological Quest on the Origin and Formation of the Stone Needle in the Korean Peninsula (폄석(砭石)의 한반도 기원과 형성에 관한 연구)

  • Yim, Yong-Soo;Sohn, In-Chul;Kang, Yeon-Seok;Kim, Seong-Chul;Kim, Jae-Hyo
    • Korean Journal of Oriental Medicine
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    • v.15 no.2
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    • pp.51-61
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    • 2009
  • Objective: Much has been known that the systematical theory of acupuncture was developed from stone needle as therapeutic tools for orthopedic diseases in ancient times. Stone needle is very old therapeutic method like moxibustion and has been recognized that it was developed since the Stone Age in China so far. In the present study, it was examined for the origination and formation of stone needle based on stone relics of the Stone Age in Korean Peninsular, the medical and geographical literatures. Materials and methods: The facts of stone needle was examined and arranged on the ancient medical or geographical literatures such as The Yellow Emperor's Canon Internal Medicine, Shanhaijing as an ancient geographical book, etc. The clan societies and family related to an origination of stone needle was chased together with their cultural characteristics and origination. The stone relics which have been digged out of historic sites in the North-East Asia were examined for a relevance to stone needle. Results: In The Yellow Emperor's Canon Internal Medicine, it was referred to the stone needle that originated from a fishery zone related to the east coast district in North-East Asia. Through the examination of Shan Hai Jing as an ancient geographical book and its historical reviews, a Go-yi clan society who keep Go's family tree dealt well with the stone needle and jewels including jade in the North-East Asia before the publication periods of The Yellow Emperor's Canon Internal Medicine, and is comprised in the culture of Dong-yi clan society but not the Chinese culture. The obsidian stones, which have been digged out of historical sites in the North-East Asia since the Stone Age, are originated from volcanic areas combined with seashore that seems to be Baekdu mountain district in Korea and Kyushu district in Japan. Furthermore, obsidian stone tools which were found out at Laodung peninsula and the Korean peninsula are archeologically similar to the stone needle with regards to the shape, size and dual-use. In addition, specific obsidian stone tools have been used in orthopedic surgery as well-crafted obsidian blades have a cutting edge up to five times sharper than high-quality steel surgical scalpels. Conclusion: The origin of obsidian stone needle is well corresponded to the explanation about that of the stone needle. It is suggested that the stone needle which influenced in completion of acupuncture and Meridian theory in China seems to be an obsidian stone, and distribution of obsidian stone needle has been closely connected to Dong-yi clan society which are lived in the North-East Asia including Baekdu-mountain district.

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Powder Metallurgy Diamond Tools - A Review of Manufacturing Routes

  • Konstanty, Janusz
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.871-872
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    • 2006
  • Nowadays the market for diamond tools grows rapidly. The present decline in the price of industrial diamond makes it a commoditised product capable of competing with conventional abrasives. In terms of production volume, the largest group of diamond tools comprises the metal-bonded diamond impregnated tools, such as sawblades, wire saws, and core drills for cutting stone and construction materials, and core bits for mining applications. This article provides a compendious coverage of the powder metallurgy (PM) diamond tool-making routes, and identifies the recent trends towards changing the tool design and composition to render it cheaper and more efficient.

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Respirable Silica Dust Exposure of Migrant Workers Informing Regulatory Intervention in Engineered Stone Fabrication

  • Mahinda Seneviratne;Kiran Shankar;Phillip Cantrell;Aklesh Nand
    • Safety and Health at Work
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    • v.15 no.1
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    • pp.96-101
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    • 2024
  • Background: Silicosis among workers who fabricate engineered stone products in micro or small-sized enterprises (MSEs) was reported from several countries. Workplace exposure data of these workers at high risk of exposure to respirable crystalline silica (RCS) dust are limited. Methods: We surveyed workers performing cutting, shaping and polishing tasks at 6 engineered stone fabricating MSEs in Sydney, Australia prior to regulatory intervention. Personal exposure to airborne RCS dust in 34 workers was measured, work practices were observed using a checklist and worker demography recorded. Results: Personal respirable dust measurements showed exposures above the Australian workplace exposure standard (WES) of 0.1 mg/m3 TWA-8 hours for RCS in 85% of workers who performed dry tasks and amongst 71% using water-fed tools. Dust exposure controls were inadequate with ineffective ventilation and inappropriate respiratory protection. All 34 workers sampled were identified as overseas-born migrants, mostly from three linguistic groups. Conclusions: Workplace exposure data from this survey showed that workers in engineered stone fabricating MSEs were exposed to RCS dust levels which may be associated with a high risk of developing silicosis. The survey findings were useful to inform a comprehensive regulatory intervention program involving diverse hazard communication tools and enforcing improved exposure controls. We conclude that modest occupational hygiene surveys in MSEs, with attention to workers' demographic factors can influence the effectiveness of intervention programs. Occupational health practitioners should address these potential determinants of hazardous exposures in their workplace surveys to prevent illness such as silicosis in vulnerable workers.

Resistance to Abrasive Wear of Materials Used as Metallic Matrices in Diamond Impregnated Tools

  • Konstanty, Janusz;Kim, Tai-Woung;Kim, Sang-Beom
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1132-1133
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    • 2006
  • Metal-bonded diamond impregnated tools are being increasingly used in the processing of stone and ceramics, road repair, petroleum exploration, etc. Although the main tool wear mechanisms have been identified, the scientific background is inadequate and fundamental research has to be carried out to better understand the tool field behaviour. This work addresses the complex issues of modelling abrasive wear of the metallic matrix under laboratory conditions. The generated data indicates that the matrix wear resistance can be assessed in a simple manner; whereas tests carried out on diamond impregnated specimens may aid prediction of the tool life in abrasive applications.

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Automatic detection of discontinuity trace maps: A study of image processing techniques in building stone mines

  • Mojtaba Taghizadeh;Reza Khalou Kakaee;Hossein Mirzaee Nasirabad;Farhan A. Alenizi
    • Geomechanics and Engineering
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    • v.36 no.3
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    • pp.205-215
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    • 2024
  • Manually mapping fractures in construction stone mines is challenging, time-consuming, and hazardous. In this method, there is no physical access to all points. In contrast, digital image processing offers a safe, cost-effective, and fast alternative, with the capability to map all joints. In this study, two methods of detecting the trace of discontinuities using image processing in construction stone mines are presented. To achieve this, we employ two modified Hough transform algorithms and the degree of neighborhood technique. Initially, we introduced a method for selecting the best edge detector and smoothing algorithms. Subsequently, the Canny detector and median smoother were identified as the most efficient tools. To trace discontinuities using the mentioned methods, common preprocessing steps were initially applied to the image. Following this, each of the two algorithms followed a distinct approach. The Hough transform algorithm was first applied to the image, and the traces were represented through line drawings. Subsequently, the Hough transform results were refined using fuzzy clustering and reduced clustering algorithms, along with a novel algorithm known as the farthest points' algorithm. Additionally, we developed another algorithm, the degree of neighborhood, tailored for detecting discontinuity traces in construction stones. After completing the common preprocessing steps, the thinning operation was performed on the target image, and the degree of neighborhood for lineament pixels was determined. Subsequently, short lines were removed, and the discontinuities were determined based on the degree of neighborhood. In the final step, we connected lines that were previously separated using the method to be described. The comparison of results demonstrates that image processing is a suitable tool for identifying rock mass discontinuity traces. Finally, a comparison of two images from different construction stone mines presented at the end of this study reveals that in images with fewer traces of discontinuities and a softer texture, both algorithms effectively detect the discontinuity traces.

Scarf Design with Application of the Pangudae Petroglyph (반구대 암각화를 응용한 스카프 디자인 연구)

  • Kim, Jong-Soon;Jang, Jeong-Dae
    • Fashion & Textile Research Journal
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    • v.9 no.3
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    • pp.262-269
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    • 2007
  • Traces of ancestors in the era without letters can be found in their legacies and remains such as stone implement, earthenware, dwelling sites, etc. Petroglyph among them reflects their life and spirits as like an epic so that we can be with them through petroglyph. petroglyph is a common culture of mankind, which has been found in various places over the world. The infinite value of traditional culture has a great impact as much as it is unnecessary to more discuss about it. When a culture of a country is reproduced as a world-class product, the country can have visible profits as well as positive effects on diverse fields. The Pangudae petroglyph in Ulsan, consistion of fishery and huntihg religiong, is one of the greatest cultural legacies of the local own uniqueness, and a source and thesaurus of design development. Despite limited tools and unskilled tact, the Pangudae petroglyph Carving shows a strong vital power, which does not change by time, of a whale or a man with various methods such as line and face carving, embossed carving, etc. under a desperate and unconditional purpose, the survival. Thus, the study tries to suggest scarf designs that applies such beauty in fashion design by using the formative beauty caused by natural abrasion through the time, and the feel of lines and stony material.

Design of watermark trace-back system to supplement connection maintenance problem

  • Kim, Hwan-Kuk;Han, Seung-Wan;Seo, Dong-Il;Lee, Sang-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2151-2154
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    • 2003
  • Internet is deeply rooted in everyday life and many things are performed using internet in real-world, therefore internet users increased because of convenience. Also internet accident is on the increase rapidly. The security vendor developed security system to protect network and system from intruder. Many hackings can be prevented and detected by using these security solutions. However, the new hacking methods and tools that can detour or defeat these solutions have been emerging and even script kids using these methods and tools can easily hack the systems. In consequence, system has gone through various difficulties. So, Necessity of intruder trace-back technology is increased gradually. Trace-back technology is tracing back a malicious hacker to his real location. trace-back technology is largely divided into TCP connection trace-back and IP packet trace-back to trace spoofed IP of form denial-of-service attacks. TCP connection trace-back technology that autonomously traces back the real location of hacker who attacks system using stepping stone at real time. In this paper, We will describe watermark trace-back system using TCP hijacking technique to supplement difficult problem of connection maintenance happened at watermark insertion. Through proposed result, we may search attacker's real location which attempt attack through multiple connection by real time.

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Research for Web Application Performance Analysis Method Based on Modern Web Browser (모던 웹 브라우저 기반 애플리케이션 성능 분석 방법 연구)

  • Park, Jin-tae;Kim, Hyun-gook;Moon, Il-young
    • Journal of Advanced Navigation Technology
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    • v.22 no.5
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    • pp.467-471
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    • 2018
  • During the fourth industrial revolution, the amount of data available to users has surged. And it became a stepping stone for various convergence technologies such as ECMA script, WebAssembly, and web of things using web technology. Also, as the amount of data shared on the web increases, the web has emerged as the most influential media in modern life. As a result, web developers have tried to deliver data quickly over the Web. So, various web application analysis tools appeared, and developers tried to find a solution to solve the speed problem by analyzing the web application. However, the performance of web application analysis tools has not improved significantly. Most existing analytical tools require direct installation, require expertise on the Web to perform analysis, and do not have function to analysis new technologies such as WebAssembly. Therefore, in this paper, we propose the design of a new reporting solution that can solve problems of existing web application analysis tool.

A SCANNING ELECTRON MICROSCOPIC STUDY OF CAVITY WALL (와동면(窩洞面)의 주사전자현미경적(走査電子顯微鏡的) 연구(硏究))

  • Lee, Myung-Jong
    • Restorative Dentistry and Endodontics
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    • v.11 no.1
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    • pp.11-18
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    • 1985
  • The purpose of this study was to observe the facial, lingual and gingival walls of the cavity walls with various kinds of cutting tools. Class II cavities were prepared in newly extracted sound humen mandibular 1st left premolars, and observed in Sanning electron microscope. Diamond point (#201) and Tungsten Carbide burs (#170L) were used in ultra high speed handpieces (rpm 200000), and Tungsten Carbide bur (#702) and Steel bur (#560) were used in conventional handpieces (rpm 6000). All cavities were prepared under water spray, except for some which were finished with a dry abrasive stone (#57). Some cavities were finished with chisels (#41, 42, 83). The following results were obtained. 1. The cavity walls prepared with Diamond point were rougher than the cavity walls with Carbide burs and Steel burs. 2. The chisels were produced the smoothest surface. 3. The cavity walls which were prepared with cutting blades rotated toward enamel surface from outside, were smoother than cavity walls which were prepared with cutting blades rotated toward outside from the enamel surface.

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