• Title/Summary/Keyword: 빙하

Search Result 1,085, Processing Time 0.032 seconds

Analysis of Cutting Characteristic of the Sapphire Wafer Using a Internal Laser Scribing Process for LED Chip (LED 칩 제조용 사파이어 웨이퍼 절단을 위한 내부 레이저 스크라이빙 가공 특성 분석)

  • Song, Ki-Hyeok;Cho, Yong-Kyu;Kim, Byung-Chan;Kang, Dong-Seong;Cho, Myeong-Woo;Kim, Jong-Su;Ryu, Byung-So
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.16 no.9
    • /
    • pp.5748-5755
    • /
    • 2015
  • Scribing is cutting process to determine production amount and characteristic of LED chip. So it is an important process for fabrication of LED chip. Mechanical process and conventional scribing process with laser source has several problems such as thermal deformation, decreasing of material strength and limitation of cutting region. To solve these problems, internal laser scribing process that generates void in wafer and derives self-crack has been researched. However, studies of sapphire wafer cutting by internal laser scribing process for fabrication of LED chip are still insufficient. In this paper, cutting parameters were determined to apply internal laser scribing process for sapphire wafer for fabrication of LED chip. Then, foundation of cutting condition was established to set up internal laser scribing system through investigation of cutting characteristics by several experiments.

A Preliminary Study on the Ice-induced Fatigue in Ice-going Ships (빙 해역 운항선박의 빙 유기 피로문제에 대한 기초연구)

  • Hwang, Mi-Ran;Kwon, Yong-Hyun;Lee, Tak-Kee
    • Journal of Ocean Engineering and Technology
    • /
    • v.30 no.4
    • /
    • pp.303-309
    • /
    • 2016
  • As commercialization of the Arctic sea route and resource developments are regularized, demands for ice-breaking tankers, LNG carriers, and offshore plants are expected to increase. In addition, the existing ice-breaking cargo ships navigating in the ice-covered waters are worn out. Hence, the construction of new ships is likely to be undertaken for both current and long-term applications. The design of ships navigating in ice-covered waters demands conservative methods and strict development standards owing to the extreme cold and collision tendencies with ice floes and/or icebergs. ISO 19906 recently stated that a fatigue limit should be defined when designing Arctic offshore structures such that the ice-induced fatigue becomes one of the important design drivers. Thus, establishing systematic measures to mitigate ice-induced fatigue problems in ice-breaking ships are important from the viewpoint of having a competitive advantage. In this paper, the issues relating to ice-induced fatigue problems, based on data and published literature, are examined to describe the criticality of ice-induced fatigue. Potential fatigue damage possibilities are investigated using data measured in the Arctic Ocean (2013) and using the Korean icebreaker, ARAON.

A Study of Metadata for Composite Electronic Records Archiving: With a Focus on Digital Components of E-Learning Contents (복합전자기록물 아카이빙을 위한 메타데이터에 관한 연구 - 이러닝 콘텐츠의 디지털 컴포넌트를 중심으로 -)

  • Lee, Inhyeok;Park, Heejin
    • Journal of Korean Society of Archives and Records Management
    • /
    • v.17 no.3
    • /
    • pp.115-138
    • /
    • 2017
  • Electronic record types are becoming diverse, and "composite electronic records," which are made up of various types of electronic records associated with functionality or user interaction that does not exist in current electronic document formats, are increasing. To ensure a continuous access to composite electronic records, metadata construction is a prerequisite for electronic records archiving. In this paper, we propose a metadata that can support archiving of composite electronic records associated with interactive functionality. The common elements were derived from an analysis of both domestic and international file format registry projects, and metadata elements related to functional requirements were identified from the analysis of the records on nursing education e-learning contents. We proposed the metadata elements for archiving composite electronic records, which consist of 25 high-level elements and 138 subelements.

The Effects of Self-management Technique on Eco-driving Behaviors (자기-관리 기법이 운전자의 에코 드라이빙 행동에 미치는 효과)

  • Kyehoon Lee ;Shinjung Choi ;Insub Choi ;Shezeen Oah
    • Korean Journal of Culture and Social Issue
    • /
    • v.17 no.4
    • /
    • pp.381-393
    • /
    • 2011
  • Eco driving is a strategy to reduce energy consumption and greenhouse gas emissions from motor vehicle. However, it has not received much attention until recently. Psychological studies on this issue have been limited and the majority of existing studies have primarily been based on engineering and educational approaches. This study examined the effects of a self-management technique on two driving behaviors: speeding and putting the gears in neutral while waiting at the signal. The self-management technique consisted of three behavior interventions: goal-setting, self-monitoring, and reward. Three drivers participated in this study. An AB multiple baseline design across participants was adopted. Results showed that the self-management technique was effective in increasing both driving behaviors. Implications of the present findings and suggestions for future research were discussed.

  • PDF

Archiving Situation and Improvement Strategy of Video Resources in Korea (우리나라 영상분야 자원관리 현황 및 개선전략)

  • Kim, Sun-Ae
    • Journal of the Korean BIBLIA Society for library and Information Science
    • /
    • v.20 no.4
    • /
    • pp.131-142
    • /
    • 2009
  • Visual industry can contribute to this national industry is a high-value industry. Nevertheless, video resources expansion strategy at national level is lacking. There have been several institutions and organization conducting film archiving and related activities in Korea. Korean Film Archive(KOFA) is the only institution whose status is protected by the law. The purpose of this study was to suggest the strategic plan which is able to support the video industry and academic research. For methods to strengthen video resources, role adjustment of KOFA conducting film archiving and unification or integration of collection system for archiving broadcast materials were proposed.

Establishment of an Ice Core Processing Method and Analytical Procedures for Fundamental Proxies (빙하코어의 전처리 방법 및 기초 프록시 분석법 확립)

  • Jun, Seong Joon;Hong, Sang Bum;Hur, Soon Do;Lee, Jeonghoon;Kang, Jung-Ho;Hwang, Hee Jin;Chung, Ji Woong;Jung, Hye Jin;Han, Changhee;Hong, Sungmin
    • Ocean and Polar Research
    • /
    • v.36 no.1
    • /
    • pp.13-24
    • /
    • 2014
  • We established the first complete ice core processing method and analytical procedures for fundamental proxies, using a 40.2 m long ice core drilled on the Mt. Tsambagarav glacier in the Mongolian Altai mountains in July 2008. The whole core was first divided into two sub ice core sections and the measurements of the visual stratigraphy and electrical conductivity were performed on the surface of these sub core sections. A continuous sequence of samples was then prepared for chemical analyses (stable isotope ratios of oxygen ($^{18}O/^{16}O$) and hydrogen ($^2H/^1H$), soluble ions and trace elements). A total of 29 insoluble dust layers were identified from the measurement of visual stratigraphy. The electrical conductivity measurement (ECM) shows 11 peaks with the current more than 0.8 ${\mu}A$ Comparing the profiles of $SO_4{^{2-}}$ and $Cl^-$ concentrations to correlate with known volcanic eruptions, the first two ECM peaks appear to be linked to the eruptions (January and June 2007) of Kliuchevskoi volcano on the Kamchatka Peninsula of Russia, which supports the reliability of our ECM data. Finally, the composition of stable isotopes (${\delta}^{18}O$ and ${\delta}D$) shows a well-defined seasonal variation, suggesting that various chemical proxies may have been well preserved in the successive ice layers of Tsambagarav ice core. Our ice core processing method and analytical procedures for fundamental proxies are expected to be used for paleoclimate and paleoenvironmental studies from polar and alpine ice cores.

Holocene Glaciomarine Sedimentation in Marian Cove, King George Island, West Antarctica (서 남극 킹조지 섬 마리안 소만의 홀로세 빙해양 퇴적작용)

  • Chang, Soon-Keun;Yoon, Ho-Il
    • Journal of the Korean earth science society
    • /
    • v.21 no.3
    • /
    • pp.276-286
    • /
    • 2000
  • A 2.3 m-long core obtained from Marian Cove, King George Island in the South Shetland Islands, West Antarctica shows clues to the glaciomarine sedimentation during the Holocene. The lower part below 115cm-deep of the core is predominated by coarser material such as diamictons compared with the higher part above 105cm dominated by finer material (rhythmite and massive muds). Based on the granulometric features the coarse materials are generally supposed to be glacially-driven and basal tills, whereas the fine materials appear to originate from various sources such as meltwater-supplied, glacially-supplied, wind-blown, and organic origins. However, the presence of erratic coarse particles in the finer materials suggests the ice-rafted origin of the relevant materials. The lower part below 105cm-deep of the core was characterized by lower TN, TC, and TOC contents, and by higher TS and CaCO$_3$ contents compared with its upper part. No significant changes in C/N ratio were shown throughout the core. The ice cliff along the east side of Marian Cove seemed to locate to the west by 1.6km at 8,300 years B. P. on the basis of the repetitive occurrence of rhythmite and diamicton. Since the retreat of ice cliff in 7,970${\pm}$70 years B. P. the sediments of Marian Cove were dominated by fine materials and ice-rafted materials. The abrupt increase of coarse materials in 175cm-4 deep seems to result from supply of coarse materials due to earthquake or other drastic phenomena.

  • PDF

Microbial Community of the Arctic Soil from the Glacier Foreland of Midtre Lovénbreen in Svalbard by Metagenome Analysis (북극 스발바르 군도 중앙로벤 빙하 해안 지역의 토양 시료 내 메타지놈 기반 미생물 군집분석)

  • Seok, Yoon Ji;Song, Eun-Ji;Cha, In-Tae;Lee, Hyunjin;Roh, Seong Woon;Jung, Ji Young;Lee, Yoo Kyung;Nam, Young-Do;Seo, Myung-Ji
    • Microbiology and Biotechnology Letters
    • /
    • v.44 no.2
    • /
    • pp.171-179
    • /
    • 2016
  • Recent succession of soil microorganisms and vegetation has occurred in the glacier foreland, because of glacier thawing. In this study, whole microbial communities, including bacteria, archaea, and eukaryotes, from the glacier foreland of Midtre Lovénbreen in Svalbard were analyzed by metagenome sequencing, using the Ion Torrent Personal Genome Machine (PGM) platform. Soil samples were collected from two research sites (ML4 and ML7), with different exposure times, from the ice. A total of 2,798,108 and 1,691,859 reads were utilized for microbial community analysis based on the metagenomic sequences of ML4 and ML7, respectively. The relative abundance of microbial communities at the domain level showed a high proportion of bacteria (about 86−87%), whereas archaeal and eukaryotic communities were poorly represented by less than 1%. The remaining 12% of the sequences were found to be unclassified. Predominant bacterial groups included Proteobacteria (40.3% from ML4 and 43.3% from ML7) and Actinobacteria (22.9% and 24.9%). Major groups of Archaea included Euryarchaeota (84.4% and 81.1%), followed by Crenarchaeota (10.6% and 13.1%). In the case of eukaryotes, both ML4 and ML7 samples showed Ascomycota (33.8% and 45.0%) as the major group. These findings suggest that metagenome analysis using the Ion Torrent PGM platform could be suitably applied to analyze whole microbial community structures, providing a basis for assessing the relative importance of predominant groups of bacterial, archaeal, and eukaryotic microbial communities in the Arctic glacier foreland of Midtre Lovénbreen, with high resolution.

A Study on Documentation Strategy for Archiving Locality (지역 아카이빙을 위한 기록화방안 연구)

  • Kwon, Soon-Myung;Lee, Seung-Hwi
    • The Korean Journal of Archival Studies
    • /
    • no.21
    • /
    • pp.41-84
    • /
    • 2009
  • Lots of cultures, memories, histories of the local life have disappeared. Some sectors of universities and religion have keep their records in manuscript archive only. On the other hand records of public sectors were at least able to be managed by the records management law. Citizen's groups and academic bounds were also roles to get public records strong. However can we just describe whole body with only public records? As records management law a record of private sector which has value of preserving can be managed under national protection. Yet establishment of local archive is not obligate. Only stressing on public records is like what dictatorial government acted in past years. It is what we ignore diversity and request of community. We need to move our view that we have focused on public and central sectors to private and local sectors. Local records management based on locality could help to complete the entire puzzle. The way complete the puzzle is various and wide spheres including from cultural space to being extinct village. Locality is defined as the property in certain area or distinctiveness of locals. Establishing production strategies is as important as collecting records produced over the past years for local archiving. Local archiving has to be regionally conducted in phase. Moreover common wealth and recognition of communities are reflected in the acquisition process. In next to archiving local organizations and private records according to collection policy, methodology on local archiving needs for archive management and use in various public and private fields. This methodology could be possible by building a local archive networking tool. It is true that Local archiving is not familiar and clear yet. If we can turn the effort for public records we have made to endeavor for private sectors, we might expect big fruits in private sectors. We easily emphasis on globalization or internationalization, our daily lives start on our villages. Setting aside our small communities, such a puzzle of the whole would never be completed. This is good time to begin finding lost puzzle for future. The key that can find lost puzzles be held in archiving localities.

Microbiological Safety Evaluation on Ice Cream and Ice Pop Products (빙과류의 품목별 제품의 미생물학적 안전성 평가)

  • Yu, Jeong-Wan;Kim, So-Hyun;Hong, Dong-Lee;Kim, Hyeon-Jae;Jeong, Eun-Joo;Lee, Jae-Hwa;Yang, Ji-Young;Lee, Yang-Bong
    • Journal of Food Hygiene and Safety
    • /
    • v.34 no.4
    • /
    • pp.367-373
    • /
    • 2019
  • In order to evaluate the microbiological safety of ice cream products, the total viable bacterial counts were measured in 6 kinds of ice pops, 5 kinds of non-milk fat ice cream, and 5 kinds of milk fat ice cream, sold in local markets. In addition, E. coli, S. aureus, B. cereus, and L. monocytogenes were artificially inoculated in three types of ice cream products and stored at $-5^{\circ}C$, $-10^{\circ}C$, and $-18^{\circ}C$, respectively, and after inoculation, viable cells were measured periodically. As a result of the total viable count, about 1~2 log CFU/mL was detected in 16 kinds of ice cream products. As a result of inoculation with microorganisms at various temperatures, the number of viable cells decreased as the storage period became longer, and the higher the storage temperature, the faster the microorganisms died. Especially, the microorganisms were killed faster in the ice pop products than in the other ice cream products, and the microorganisms were killed relatively slower in the milk ice cream. L. monocytogenes and S. aureus were relatively stable in frozen conditions compared to other microorganisms. The microbial contamination of commercial ice cream was lower than the allowable standard of the Korean Food Code. Microorganisms did not proliferate when the microorganism was inoculated at freezing temperature. Therefore, it is expected that the microbiological safety of frozen foods will be ensured if the sanitary control and disinfection of raw materials are thoroughly carried out during the production of frozen confections and the temperature control during distribution and storage is well maintained.