Given the US dollar's status as a global safe haven, global factors, such as US monetary policy, may have considerable impacts on financial markets in other countries. Regarding such hypothesis, this paper looked at the impacts of US monetary policy on domestic bond and FX swap markets through an event study. According to our analysis, US monetary policy had significant positive impacts on domestic interest rates. In particular, it turned out to have bigger impacts on long-term products with high term premiums. By period, the correlation between US monetary policy and domestic interest rates was not significant before the financial crisis, but was clearly positive after the crisis. The US conventional monetary policy was seen to have big impacts on short-term and medium-term KTB yields, while its unconventional monetary policy had major impacts on long-term KTB yields. Moreover, FX swap rates reacted very sensitively to US monetary policy shocks before the financial crisis, while they did not show any significant reactions after the crisis. This suggests that, in line with the covered interest rate parity, the impact of US monetary policy shocks was transmitted to domestic financial markets mainly through swap rate adjustments before the global financial crisis, but through the changes in domestic interest rates during the post-crisis period.
Kim, Sun-Young;Cho, Byeong-Hoon;Baek, Seung-Ho;Lee, In-Bog
Restorative Dentistry and Endodontics
/
v.33
no.4
/
pp.405-412
/
2008
This study was aimed to investigate whether an oxygen inhibition layer (OIL) is essential for the interfacial bonding between resin composite layers or not. A composite (Z-250, 3M ESPE) was filled in two layers using two aluminum plate molds with a hole of 3.7 mm diameter. The surface of first layer of cured composite was prepared by one of five methods as followings, thereafter second layer of composite was filled and cured: Group 1 - OIL is allowed to remain on the surface of cured composite; Group 2 - OIL was removed by rubbing with acetone-soaked cotton; Group 3 - formation of the OIL was inhibited using a Mylar strip; Group 4 - OIL was covered with glycerin and light-cured; Group 5 (control) - composite was bulk-filled in a layer. The interfacial shear bond strength between two layers was tested and the fracture modes were observed. To investigate the propagation of polymerization reaction from active area having a photo-initiator to inactive area without the initiator, a flowable composite (Aelite Flow) or an adhesive resin (Adhesive of ScotchBond Multipurpose) was placed over an experimental composite (Exp_Com) which does not include a photoinitiator and light-cured. After sectioning the specimen, the cured thickness of the Exp_Com was measured. The bond strength of group 2, 3 and 4 did not show statistically significant difference with group 1. Groups 3 and 4 were not statistically significant different with control group 5. The cured thicknesses of Exp_Com under the flowable resin and adhesive resin were 20.95 (0.90) urn and 42.13 (2.09), respectively.
A central pullout test was conducted to investigate the bonding properties between high strength rebar and reactive powder concrete (RPC), which covered ultimate pullout load, ultimate bonding stress, free end initial slip, free end slip at peak load, and load-slip curve characteristics. The effects of varying rebar buried length, thickness of protective layer and diameter of rebars on the bonding properties were studied, and how to determine the minimum thickness of protective layer and critical anchorage length was suggested according the test results. The results prove that: 1) Ultimate pull out load and free end initial slip load increases with increase in buried length, while ultimate bonding stress and slip corresponding to the peak load reduces. When buried length is increased from 3d to 4d(d is the diameter of rebar), after peak load, the load-slip curve descending segment declines faster, but later the load rises again exceeding the first peak load. When buried length reaches 5d, rebar pull fracture occurs. 2) As thickness of protective layer increases, the ultimate pull out load, ultimate bond stress, free end initial slip load and the slip corresponding to the peak load increase, and the descending section of the curve becomes gentle. The recommended minimum thickness of protective layer for plate type members should be the greater value between d and 10 mm, and for beams or columns the greater value between d and 15 mm. 3) Increasing the diameter of HRB500 rebars leads to a gentle slope in the descending segment of the pullout curve. 4) The bonding properties between high strength steel HRB500 and RPC is very good. The suggested buried length for test determining bonding strength between high strength rebars and RPC is 4d and a formula to calculate the critical anchorage length is established. The relationships between ultimate bonding stress and thickness of protective layer or the buried length was obtained.
Kim, Moo-Han;Kim, Gyu-Yong;Khil, Bae-Su;Cho, Bong-Suk;Lee, Eui-Bae
Journal of the Korea Concrete Institute
/
v.18
no.3
s.93
/
pp.371-378
/
2006
Recently sewage facilities mainly consisted of concrete structures are being deteriorated seriously by biodeterioration originated from sulfur-oxidizing bacteria. In this study, to prevent biochemical corrosion of the sewer concrete, antibiotics which prevent growth of sulfur-oxidizing bacteria were developed and antimicrobial performance of it was investigated. After that, to consider applicability of antibiotics to concrete, physical properties of concrete covered with antibiotics were investigated. As a results of the study, it was proved that the antimicrobial performance of antibiotics was available. Also compressive strength and bond strength of concrete didn't closely connected with antibiotics, and resistance to abrasion, water absorption, air permeability, carbonation, salt damage and chemical attack of concrete was improved remarkably by covering with it.
Korean Journal of Construction Engineering and Management
/
v.12
no.3
/
pp.53-61
/
2011
After several collapse accidents of large structures in the early 1990s in Korea, the government enacted a law that architectural, engineering and construction firms are obliged to have insurance for projects over a certain size. Particularly, with regard to insurance in design and construction supervision works (i.e. engineering insurance), although several operation-based problems were pointed out from practitioners, still little research has been done on analyzing current regnlartory and operational state and suggesting policy alternatives. Hence, this study applies Delphi technique to solicit current operational problems and propose a series of improvements on engineering insurance based on interview surveys targeting major market participants: municipalities, engineering firms, and insurance companies. Key findings culminate in adopting guarantee limits based on credit evaluation, abrogating joint surety, covering a loss of life, increasing insurance entrance fee, extending time covered, and etc. Reaching a consensus on the proposed alternatives between the market participants will form the foundation for sound developments of construction design and engineering industry.
Objective: The aim of this study was to evaluate the mechanical and biological properties of orthodontic bonding agents containing silver- or zinc-doped bioactive glass (BAG) and determine the antibacterial and remineralization effects of these agents. Methods: BAG was synthesized using the alkali-mediated solgel method. Orthodontic bonding agents containing BAG were prepared by mixing BAG with flowable resin. $Transbond^{TM}$ XT (TXT) and $Charmfil^{TM}$ Flow (CF) were used as controls. Ion release, cytotoxicity, antibacterial properties, the shear bond strength, and the adhesive remnant index were evaluated. To assess the remineralization properties of BAG, micro-computed tomography was performed after pH cycling. Results: The BAG-containing bonding agents showed no noticeable cytotoxicity and suppressed bacterial growth. When these bonding agents were used, demineralization after pH cycling began approximately 200 to $300{\mu}m$ away from the bracket. On the other hand, when CF and TXT were used, all surfaces that were not covered by the adhesive were demineralized after pH cycling. Conclusions: Our findings suggest that orthodontic bonding agents containing silver- or zinc-doped BAG have stronger antibacterial and remineralization effects compared with conventional orthodontic adhesives; thus, they are suitable for use in orthodontic practice.
The purpose of this study is to evaluate the effect of additional enamel etching with phosphoric acid on the microleakage of the adhesion of self-etching primer system. Class V cavity($4mm{\times}3mm{\times}1.5mm$) preparations with all margins in enamel were prepared on buccal surface of 42 extracted human upper central incisor teeth. Prepared teeth were randomly divided into 3 groups. Group 1:no additional pretreatment with 37% phosphoric acid (NE). Group 2:additional pretreatment with 37% phosphoric acid for 10 seconds (E10s). Group 3:additional pretreatment with 37% phosphoric acid for 20 seconds (E20s). The adhesives(Clearfil SE $Bond^{\circledR}$, Kuraray, Osaka, Japan) and composite resins(Clearfil $AP-X^{\circledR}$, Osaka, Kuraray, Japan) were applied following the manufacturer's instructions. All the specimens were finished with the polishing disc(3M dental product, St Paul, MN, USA), thermocycled for 500 cycles between $5^{\circ}C$ and $55^{\circ}C$ and resected apical 3-mm root. 0.028 stainless steel wire was inserted apically into the pulp chamber of each tooth and sealed into position with sticky wax. Surrounding tooth surface was covered with a nail varnish 2 times except areas 1mm far from all the margins. After drying for one day, soaked the samples in the distilled water. Microleakage was assessed by electrochemical method(System 6514, $Electrometer^{\circledR}$), Keithley, USA) in the distilled water. In this study, the microleakage was the lowest in group 1 (NE) and the highest in group 3(E20s)(NE
Ha, Kyoung-Ho;Kang, Dae-Min;Lee, Jung-Hee;Kwak, Jae-Seob
Journal of the Korean Society of Manufacturing Process Engineers
/
v.18
no.2
/
pp.1-6
/
2019
With the increase in number of the athletic population and elderly demographic, the demand for orthopedic splints, which are used to support a damaged body, has rapidly increased. Current splints mainly consist of inner and outer parts, which are multiple fabrics covered with polyurethane and nonwoven fabrics, respectively. However, the laminated materials with directly applied pre-polymer coating lead to a high defect rate because of the uneven thickness on the surface. Thus, this study proposes an indirect coating method using a precise clearance controller, which enables the even application of the coating material on multiple inner parts while maintaining a constant thickness. In addition, a roll-to-roll (R2R) technique is applied instead of the sewing mechanism to bond the inner and outer materials together and enhance the productivity in the final stage. In the advanced methods, there is a storage tank that contains polyurethane, a clearance controller, and pairs of rollers in the upper and lower rows. To improve the quality of the products and optimize the equipment, three controllable factors are determined: the viscosity of polyurethane, angle of the gap controller and number of pairs of rollers in the R2R system.
Services using artificial intelligence have begun to emerge in daily life. Artificial intelligence is applied to products in consumer electronics and communications such as artificial intelligence refrigerators and speakers. In the financial sector, using Kensho's artificial intelligence technology, the process of the stock trading system in Goldman Sachs was improved. For example, two stock traders could handle the work of 600 stock traders and the analytical work for 15 people for 4weeks could be processed in 5 minutes. Especially, big data analysis through machine learning among artificial intelligence fields is actively applied throughout the financial industry. The stock market analysis and investment modeling through machine learning theory are also actively studied. The limits of linearity problem existing in financial time series studies are overcome by using machine learning theory such as artificial intelligence prediction model. The study of quantitative financial data based on the past stock market-related numerical data is widely performed using artificial intelligence to forecast future movements of stock price or indices. Various other studies have been conducted to predict the future direction of the market or the stock price of companies by learning based on a large amount of text data such as various news and comments related to the stock market. Investing on commodity asset, one of alternative assets, is usually used for enhancing the stability and safety of traditional stock and bond asset portfolio. There are relatively few researches on the investment model about commodity asset than mainstream assets like equity and bond. Recently machine learning techniques are widely applied on financial world, especially on stock and bond investment model and it makes better trading model on this field and makes the change on the whole financial area. In this study we made investment model using Support Vector Machine among the machine learning models. There are some researches on commodity asset focusing on the price prediction of the specific commodity but it is hard to find the researches about investment model of commodity as asset allocation using machine learning model. We propose a method of forecasting four major commodity indices, portfolio made of commodity futures, and individual commodity futures, using SVM model. The four major commodity indices are Goldman Sachs Commodity Index(GSCI), Dow Jones UBS Commodity Index(DJUI), Thomson Reuters/Core Commodity CRB Index(TRCI), and Rogers International Commodity Index(RI). We selected each two individual futures among three sectors as energy, agriculture, and metals that are actively traded on CME market and have enough liquidity. They are Crude Oil, Natural Gas, Corn, Wheat, Gold and Silver Futures. We made the equally weighted portfolio with six commodity futures for comparing with other commodity indices. We set the 19 macroeconomic indicators including stock market indices, exports & imports trade data, labor market data, and composite leading indicators as the input data of the model because commodity asset is very closely related with the macroeconomic activities. They are 14 US economic indicators, two Chinese economic indicators and two Korean economic indicators. Data period is from January 1990 to May 2017. We set the former 195 monthly data as training data and the latter 125 monthly data as test data. In this study, we verified that the performance of the equally weighted commodity futures portfolio rebalanced by the SVM model is better than that of other commodity indices. The prediction accuracy of the model for the commodity indices does not exceed 50% regardless of the SVM kernel function. On the other hand, the prediction accuracy of equally weighted commodity futures portfolio is 53%. The prediction accuracy of the individual commodity futures model is better than that of commodity indices model especially in agriculture and metal sectors. The individual commodity futures portfolio excluding the energy sector has outperformed the three sectors covered by individual commodity futures portfolio. In order to verify the validity of the model, it is judged that the analysis results should be similar despite variations in data period. So we also examined the odd numbered year data as training data and the even numbered year data as test data and we confirmed that the analysis results are similar. As a result, when we allocate commodity assets to traditional portfolio composed of stock, bond, and cash, we can get more effective investment performance not by investing commodity indices but by investing commodity futures. Especially we can get better performance by rebalanced commodity futures portfolio designed by SVM model.
Jung, Eunjin;Lee, Yoon Joo;Kim, Younghee;Kwon, Woo Teck;Shin, Dong-Geun;Kim, Soo Ryong
Korean Chemical Engineering Research
/
v.53
no.2
/
pp.247-252
/
2015
ZSM-5 crystals grew on the surface of ${\alpha}$-SiC and ${\beta}$-SiC particles by hydrothermal synthesis method. SiC particles which were > $50{\mu}m$ of size were used, and oxide layer were developed on the surface of the particles to induce growth of ZSM-5 from the surface. Then, synthesis time and temperature condition were considered growing ZSM-5. In this study, oxide layer was formed on ${\beta}$-SiC at $900^{\circ}C$ in air, and it was controlled to grow ZSM-5 grew from the ${\beta}$-SiC surface with $150^{\circ}C$ synthesis condition. This is due to Si-O-Si or Si-O-Al bond, which is basic framework of ZSM-5 can be easily formed, from the silicon oxide film on the surface of ${\beta}$-SiC. When the synthesis temperature was $200^{\circ}C$, the size of ZSM-5 was increased, and it covered much area of the SiC surface with better crystal shapes with longer synthesis time.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.