• Title/Summary/Keyword: Spring force

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A Study on the Roles and Revision of eUCP for Global Electronic Trading (글로벌 전자무역의 실현을 위한 eUCP의 역할과 개정방안)

  • Choi, Seok-Beom;Hong, Sung-Kyu
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.18
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    • pp.105-134
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    • 2002
  • In the Spring of 2000, the Banking Commission of the ICC decided to appoint a working group to draft a supplement to the UCP 500 to clarify the position regarding electronic presentation under a documentary credit. Provisions was drafted to supplement its existing rules for documentary credit, that is, UCP 500. These new provisions known as Supplement to UCP 500 for Electronic Presentation was approved by the ICC Banking Commission at the beginning of November 2001 and came in force as of 1 April 2002 The eUCP covers matters such as definitions of key terms such as electronic record, electronic signature, format, paper document, received. An eUCP Credit must specify the formats in which electronic records are to be presented and if not, electronic records may be presented in any format. Electronic records may be presented separately and need not be presented at the same time. The purpose of this paper is to understand the main substance of eUCP and to facilitate the introduction of electronic letter of credit by studying the problems and revision of eUCP and new electronic UCP. The main substances of eUCP are electronic address as place for presentation of electronic records, flexibility of the formats of electronic records to be presented, endowment of the notice of completeness of presentation to the beneficiary, one electronic record satisfying one or more originals or copies of an electronic record, the electronic records to be examined including the electronic record at the hyperlink to an external system or the referenced system, no remark as to the time period for the examination of documents. The Roles of eUCP are the Promotion of the Electronic Trade, the Supply of Basis on the Uniform Rules for Electronic Letter of Credit, the introduction of Electronic Trade Model. The characteristics of eUCP are a supplement to the UCP, no address of any issues relating to the issuance or advice of Credit electronically, independence of specific technologies and developing electronic commerce system, that is, Bolero Service. The Problems of eUCP are flexibility of format of electronic record, heavy burden on the side of banks, and the problems regrading the number of presentation, the notice of completeness of presentation, no provision in regard to the time to examine the electronic records, and representation of the electronic records. In the revision of eUCP to resolve the problems, the things to be taken into consideration are as follows; the designation of the format allowing the banks to examine electronically, prohibition of the paper documents, the development of the system receiving the electronic records, the addition of the reception notice on the side of the banks, the setting of the time to examine the electronic records, the construction of the backup system or the dual processing system.

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Serosurveillance of Scrub Typhus in Small Mammals Collected from Military Training Sites near the DMZ, Northern Gyeonggi-do, Korea, and Analysis of the Relative Abundance of Chiggers from Mammals Examined

  • Kim, Heung-Chul;Lee, In-Yong;Chong, Sung-Tae;Richards, Allen L.;Gu, Se-Hun;Song, Jin-Won;Lee, John S.;Klein, Terry A.
    • Parasites, Hosts and Diseases
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    • v.48 no.3
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    • pp.237-243
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    • 2010
  • Comprehensive quarterly serosurveillance on scrub typhus in small mammals collected from military training sites located near the Demilitarized Zone (DMZ), northern Gyeonggi-do (Province), ROK was conducted to determine the potential rodent-borne and associated ectoparasite disease risks to military personnel. A total of 1,196 rodents and insectivores representing 8 species, Apodemus agrarius (87.3%, n = 1,044), Mus musculus (5.4%, n = 65), Crocidura lasiura (3.3%, n = 40), Microtus fortis (2.6%, n = 31), Micromys minutus (0.3%, n = 4), Tscherskia triton (0.3%, n = 4), Rattus norvegicus (0.3%, n = 4), and Myodes regulus (0.3%, n = 4) were assayed for the presence of antibodies to Orientia tsutsugamushi. O. tsutsugamushi antibodies were detected in 6 of 8 species and seroprevalence determined; A. agrarius (45.6%), M. musculus (23.1%), M. fortis (48.4%), M. minutus (50.0%), T. triton (50.0%), and R. norvegicus (25.0%). A total of 31,184 chigger mites collected from 508 rodents and insectivores were slide-mounted and 10 species belonging to 4 genera were identified. Leptotrombidium pallidum (53.4%) was the most frequently collected, followed by L. pal pale (15.7%), Neotrombicula tam/yai (14.3%), L. orientate (10.7%), L. zetum (3.1%), Walchia fragilis (2.1%), and L. gemiticutum (0.8%), while the remaining 3 species, L subintennedium, N. gardellai, and Euschoengastia koreaensis were rarely observed (prevalence < 10%). In contrast to previous surveys, higher chigger indices of the primary scrub typhus vectors, L. pallidum (165.4), L. orientale (45.0), and L. palpate (21.4), were observed during the spring season.

Process Optimization of PECVD SiO2 Thin Film Using SiH4/O2 Gas Mixture

  • Ha, Tae-Min;Son, Seung-Nam;Lee, Jun-Yong;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.434-435
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    • 2012
  • Plasma enhanced chemical vapor deposition (PECVD) silicon dioxide thin films have many applications in semiconductor manufacturing such as inter-level dielectric and gate dielectric metal oxide semiconductor field effect transistors (MOSFETs). Fundamental chemical reaction for the formation of SiO2 includes SiH4 and O2, but mixture of SiH4 and N2O is preferable because of lower hydrogen concentration in the deposited film [1]. It is also known that binding energy of N-N is higher than that of N-O, so the particle generation by molecular reaction can be reduced by reducing reactive nitrogen during the deposition process. However, nitrous oxide (N2O) gives rise to nitric oxide (NO) on reaction with oxygen atoms, which in turn reacts with ozone. NO became a greenhouse gas which is naturally occurred regulating of stratospheric ozone. In fact, it takes global warming effect about 300 times higher than carbon dioxide (CO2). Industries regard that N2O is inevitable for their device fabrication; however, it is worthwhile to develop a marginable nitrous oxide free process for university lab classes considering educational and environmental purpose. In this paper, we developed environmental friendly and material cost efficient SiO2 deposition process by substituting N2O with O2 targeting university hands-on laboratory course. Experiment was performed by two level statistical design of experiment (DOE) with three process parameters including RF power, susceptor temperature, and oxygen gas flow. Responses of interests to optimize the process were deposition rate, film uniformity, surface roughness, and electrical dielectric property. We observed some power like particle formation on wafer in some experiment, and we postulate that the thermal and electrical energy to dissociate gas molecule was relatively lower than other runs. However, we were able to find a marginable process region with less than 3% uniformity requirement in our process optimization goal. Surface roughness measured by atomic force microscopy (AFM) presented some evidence of the agglomeration of silane related particles, and the result was still satisfactory for the purpose of this research. This newly developed SiO2 deposition process is currently under verification with repeated experimental run on 4 inches wafer, and it will be adopted to Semiconductor Material and Process course offered in the Department of Electronic Engineering at Myongji University from spring semester in 2012.

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Reduction of Chattering Error of Reed Switch Sensor for Remote Measurement of Water Flow Meter (리드 스위치 센서를 이용한 원격 검침용 상수도 계량기에서 채터링 오차 감소 방안 연구)

  • Ayurzana, Odgerel;Kim, Hie-Sik
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.4 s.316
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    • pp.42-47
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    • 2007
  • To reduce the chattering errors of reed switch sensors in the automatic remote measurement of water meter a reed switch sensor was analyzed and improved. The operation of reed switch sensors can be described as a mechanical contact switch by approximation of permanent magnet piece to generate an electrical pulse. The reed switch sensors are used mostly in measurement application to detect the rotational or translational displacement. To apply for water flow measurement devices, the reed switch sensors should keep high reliability. They are applied for the electronic digital type of water flow meters. The reed switch sensor is just mounted simply on the conventional mechanical type flow meter. A small magnet is attached on a pointer of the water meter counter rotor. Inside the reed sensor two steel leaf springs make mechanical contact and apart repeatedly as rotation of flow meter counter. The counting electrical contact pulses can be converted as the water flow amount. The MCU sends the digital flow rate data to the server using the wireless communication network. But the digital data is occurred difference or won by chattering noise. The reed switch sensor contains chattering error by it self at the force equivalent position. The vibrations such as passing vehicle near to the switch sensor installed location causes chattering. In order to reduce chattering error, most system uses just software methods, for example using filter algorithm and also statistical calibration methods. The chattering errors were reduced by changing leaf spring structure using mechanical characteristics.

Impact on the characteristics by heating temperature change during orthodontic wire solder (치과교정용 wire 납착시 가열온도의 변화가 제특성에 미치는 영향)

  • Lee, Gyu-Sun
    • Journal of Technologic Dentistry
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    • v.32 no.2
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    • pp.65-74
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    • 2010
  • Purpose : To understand the impact on the strength or restoration force by the change of heating temperature when soldering 18-8 stainless steel round wire which is the chrome-nickel class for dental orthodontic device production. Methods : The following conclusions were made upon the results from tensile strength test, 3 point bending test, and $90^{\circ}$ bending fatigue test with 24 samples that had been applied with condition 1 (before heat treatment - natural) and condition 2 (after heat treatment - mooring 30 seconds after heating up to $500^{\circ}C$, $700^{\circ}C$, and $900^{\circ}C$) to ${\phi}0.4mm$, ${\phi}0.7{\beta}mm$, 18-8 stainless steel round wire (spring hard) by Jinsung Company. Results : When it was heat-treated at $900^{\circ}C$, both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low tensile strengths compared to the heat treated cases at $500^{\circ}C$ and $700^{\circ}C$ Yield strengths of both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$, as well. Upon the results of 3 point bending test, the heat treated case at $900^{\circ}C$ showed very low in both ${\phi}0.4mm$ and ${\phi}0.7mm$, compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Tensile strength of both ${\phi}0.4mm$ and ${\phi}0.7mm$ as well, showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Upon the results of $90^{\circ}$ bending fatigue test, the heat treated case at $900^{\circ}C$ showed the highest wave node resistance in both ${\phi}0.4mm$ and ${\phi}0.7mm$. Conclusion : This study concluded that heating temperature change during wire soldering impacts on the characteristics of orthodntic wire.

Measurement of EMC/PCB Interfacial Adhesion Energy of Chip Package Considering Warpage (휨을 고려한 칩 패키지의 EMC/PCB 계면 접합 에너지 측정)

  • Kim, Hyeong Jun;Ahn, Kwang Ho;Oh, Seung Jin;Kim, Do Han;Kim, Jae Sung;Kim, Eun Sook;Kim, Taek-Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.26 no.4
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    • pp.101-105
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    • 2019
  • The adhesion reliability of the epoxy molding compound (EMC) and the printed circuit board (PCB) interface is critical to the quality and lifetime of the chip package since the EMC protects PCB from the external environment during the manufacturing, storage, and shipping processes. It is necessary to measure adhesion energy accurately to ensure product reliability by optimizing the manufacturing process during the development phase. This research deals with the measurement of EMC/PCB interfacial adhesion energy of chip package that has warpage induced by the coefficient of thermal expansion (CTE) mismatch. The double cantilever beam (DCB) test was conducted to measure adhesion energy, and the spring back force of specimens with warpage was compensated to calculate adhesion energy since the DCB test requires flat substrates. The result was verified by comparing the adhesion energy of flat chip packages come from the same manufacturing process.

Effect of Foundation Flexibility of Offshore Wind Turbine on Force and Movement at Monopile Head (해상풍력발전기 기초구조물의 강성이 모노파일 두부의 부재력 및 변위에 미치는 영향)

  • Jung, Sungmoon;Kim, Sung-Ryul;Lee, Juhyung;Le, Chi Hung
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.4
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    • pp.21-31
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    • 2014
  • Recently, the research on renewable energy against depletion of fossil fuel have been actively carried out in the world. Especially, offshore wind turbines are very economical and innovative technology. However, offshore wind turbines experience large base moments due to the wind and wave loading, so the monopile with large diameter needs to be applied. For the economical design of the large diameter pile, it is important to consider the flexibility of the foundation to estimate the maximum moment accurately, based on studies conducted so far. In this paper, the foundation was modeled using the finite element method in order to better describe the large diameter effect of a monopile and the results were compared with those of p-y method. For the examples studied in this paper, the change in maximum moment was insignificant, but the maximum tilt angle from the finite element method was over 14% larger than that of p-y method. Therefore, the finite element approach is recommended to model the flexibility effect of the pile when large tilt angles may cause serviceability issues.

A Study on Scientific Concepts and Teaching and Learning Methods in the Activities of the Nuri Curriculum Teacher Guidebooks for Ages 3-5 in Accordance with Themes (생활주제를 중심으로 본 3-5세 연령별 누리과정 교사용지도서 활동의 과학개념 및 교수학습방법 분석)

  • Choi, Hye Yoon
    • Korean Journal of Child Education & Care
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    • v.18 no.4
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    • pp.65-89
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    • 2018
  • Objective: The purpose of this study is to analyze the science concepts and teaching and learning methods presented in the science education-related activities of the Nuri Curriculum teacher guidebooks for ages 3-5. Methods: The research data included 772 activities related to science education in the teachers' guidebook. The analysis of science concepts was based on physical science (force and motion, physical structure, electricity and magnetism, light and shadow, sound properties), chemistry (material properties, material reaction), life science (organizational structure, growth and change, heredity and evolution, animal plant and human relationships), earth science (earth system interaction, earth system structure, and universe), engineering (designed world, engineering design, engineering, technology and society) and ecology (environment preservation). Teaching and learning methods were analyzed according to the types of small and large group activities and of free play activities. Results: Science concepts were mainly presented in the fields of engineering, chemistry, and life science commonly among children aged 3-5, whereas the concepts of physical science were lowly presented in all ages. Science concepts appeared mainly in the daily subjects of 'animal plant and nature', 'life tools', 'environment and life', and 'spring, summer, autumn and winter'. As the teaching and learning method, free paly activities (science area, free outdoor selection activity, math and manipulative activity) were mostly used for the ages of 3 and 4, and small and large group activities (cooking, story sharing, music activity) were for the age of 5. Conclusion/Implications: It is necessary to select the level of science area and concept that can be taught according to the age of children and the timing of the teaching.

Impact of piezocision on orthodontic tooth movement

  • Papadopoulos, Nikolaos;Beindorff, Nicola;Hoffmann, Stefan;Jost-Brinkmann, Paul-Georg;Prager, Thomas Michael
    • The korean journal of orthodontics
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    • v.51 no.6
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    • pp.366-374
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    • 2021
  • Objective: This study investigated the impact of a single piezocision in the maxillary alveolar process on the speed of tooth movement. The null hypothesis was that the speed of tooth movement will be equal with and without piezocision. Methods: All maxillary molars on one side were moved against the combined incisors in 10 ten-week-old male Wistar rats. Under general anesthesia, a force of 25 cN was applied on either side using a Sentalloy closed coil spring. After placing the orthodontic appliance, vertical corticision was performed using a piezotome under local anesthesia, 2 mm mesial from the mesial root of the first molar on a randomly selected side; the other side served as the control. At the beginning of the treatment, and 2 and 4 weeks later, skull micro-computed tomography was performed. After image reconstruction, the distance between the mesial root of the first molar and the incisive canal, and the length of the mesial root of the first maxillary molar were measured. Moreover, the root resorption score was determined as described by Lu et al. Results: Significantly higher speed of tooth movement was observed on the corticision side; thus, the null hypothesis was rejected. The loss of root length and root resorption score were significantly more pronounced after piezocision than before. A strong correlation was observed between the speed of tooth movement and root resorption on the surgical side, but the control side only showed a weak correlation. Conclusions: Piezocision accelerates orthodontic tooth movement and causes increased root resorption.

Changes in CGRP-immunoreactive Nerve Fibers during Expansion of Midpalatal Suture of the Rat (백서 정중구개봉합 확대후의 CGRP 면역반응 신경섬유의 변화)

  • Kim, Bo-Kyung;Park, Kuk-Pil;Kyung, Hee-Moon;Kwon, Oh-Won;Sung, Jae-Hyun
    • The korean journal of orthodontics
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    • v.29 no.1 s.72
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    • pp.73-81
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    • 1999
  • Midpalatal suture expansion is often used for patients haying narrow maxillary arch, cleft palate, respiratory handicap with narrow nasal cavity. CGRP has been known as a modulator of pain transmission in central nervous system and a local effector to peripheral tissue causing vasodilation, increase of blood flow, modulation of immune system, regulation of macrophagic function and stimulation of bone formation. To investigate changes of CGRP-immunoreactive nerve fibers in midpalatal suture during the expansion, immunohistochemical study was performed by using rats. Experimental rats (10 weeks, 250 gm) were divided into five groups (control, 1, 4, 7, 14 days group (each n=4) and applied orthodontic force (approximately 200gm) to upper anterior incisors. Frozen sections of midpalatal suture area were immunostained by using rabbit antisera. The results were as follows. ${\cdot}$ The CGRP-immunoreactive nerve fibers were hardly observed in control group. ${\cdot}$ In 1 day group, the CGRP-immunoreactive nerve fibers were more increased around the vessels than control group. ${\cdot}$ In 4 days group, the CGRP-immunoreactive nerve fibers were more increased than control group, but not more increased than 1 day group. Vascular diameter was more enlarged. ${\cdot}$ In 7 days group, especially, hematoxilin affinity of cells was remarkable and cells were arranged along the bone margin. The CGRP-immunoreactive nerve fibers were more reduced than 4 days group and vascular diameter was also reduced. ${\cdot}$ In 14 days group, the CGRP-immunoreactive nerve fibers were similar to those of 7 days group and the irregularity of bone margin was almost recoverd. In Conclusion, the CGRP-immunoreactive nerve fibers nay be related to initial neurogenic inflammatory reaction in expanding mid-palatal suture.

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