Park, Jong-Geun;Ahn, Jongsun;Jun, Hyang-Sig;Yeom, Chan-Hong;Sung, Sangkyung;Lee, Young Jae
Journal of the Korean Society for Aeronautical & Space Sciences
/
v.42
no.5
/
pp.368-375
/
2014
The Ground Based Augmentation System (GBAS) is influenced by environmental factors, making analysis in the installation region important. This study has proposed the sigma inflation of the B-value considering the satellite elevation angle and analyzed the Vertical Protection Level (VPL) of the H1 hypothesis. After collecting data that meet the environmental conditions of the installation region, sigma expansion coefficients by the unit of satellite elevation angle ($5^{\circ}$) have been estimated. The obtained results were functionalized through curve-fitting, and sigma inflation customized for the environmental conditions of the test region was proposed. Then, the characteristics were classified and analyzed depending on humidity and solar activities. According to the sigma inflation with respect to elevation angle analysis, changes in the size of sigma inflation factors by the difference of humidity were minor. However, the VPL under the satellite elevation angle-based sigma inflation met integrity. Also, considering the sigma inflation factor with respect to elevation angle, compared to existing methods, high-integrity and improved availability is confirmed by removing unnecessary margins in high elevation angle satellite.
Journal of the Microelectronics and Packaging Society
/
v.22
no.3
/
pp.25-30
/
2015
SAC-coated Cu specimens were fabricated by novel pad finish process using a phenomenon that metal nanoparticles less than 20 nm in diameter melted at a temperature lower than the melting point of bulk metal, and their wettabilities were evaluated. The thickness of SAC305 layer coated at low temperature of $160^{\circ}C$ using SAC305 ink was extremely thin as the level of several nanometers. It was analyzed by Auger electron spectroscopy that $Cu_6Sn_5$ intermetallic layer with a thickness of 10~100 nm and $Cu_3Sn$ intermetallic layer with a thickness of 50~150 nm were sequentially formed under the SAC305 coating layer. The thickness of formed intermetallic layers was thicker in electroplated Cu than rolled Cu, which attributed to improved surface roughness in the electroplated Cu. The improved surface roughness induces the contact, melting, and reaction of a larger number of SAC305 nanoparticles per the unit area of Cu specimen. In the wetting angle test using SAC305 solder balls, the Cu coated with SAC305 through the low temperature process presented evidently low wetting angles than those in non-coated Cu, indicating that only a few nanometer-thick SAC305 coating layer on Cu could also cause the enhancement of wettability.
In this study, a series of laboratory and in-situ tests such as FVTs and CPTUs were carried out to evaluate undrained shear strength related to quasi overconsolidated characteristics in the near-surface clay at Busan new port. Using unconfined compression and field vane test results, correlation between undrained shear strength and effective overburden pressure, that is, equation of $10+0.262{\sigma}^{\prime}v_0$ (kPa) was obtained. From oedometer tests, OCR is around 1.9 at depths lower than 7 m and OCR below this depth is very close to unit. As stated by Hanzawa et al. (1983), a natural clay deposit in the near-surface, even in normally consolidated state, is more and less apparently overconsolidated due to aging effects such as chemical bonding. Based on this concept, it can be inferred that intercept of equation is mobilized due to chemical bonding irrespective of effective overburden pressure and strength incremental ratio in normally consolidated state is 0.262. From CPTU results, same trend was confirmed. The further study should be necessary to judge whether upper clay is under overconsolidated state due to chemical bonding or not based on the depositional environment.
Song, Seung Eon;Lee, Sang Hee;Jo, Eun-Jung;Eom, Jung Seop;Mok, Jeong Ha;Kim, Mi-Hyun;Kim, Ki Uk;Lee, Min Ki;Lee, Kwangha
Tuberculosis and Respiratory Diseases
/
v.79
no.4
/
pp.289-294
/
2016
Background: The aim of our study was to evaluate the prognostic value of Charlson's weighted index of comorbidities (WIC) in patients with prolonged acute mechanical ventilation (PAMV, ventilator care ${\geq}96$ hours). Methods: We retrospectively enrolled 299 Korean PAMV patients who were admitted in a medical intensive care unit (ICU) of a university-affiliated tertiary care hospital between 2008 and 2013. Survivors were defined as patients who survived for 60 days after ICU admission. Results: The patients' mean age was $65.1{\pm}14.1$ years and 70.6% were male. The mean ICU and hospital length of stay was $21.9{\pm}19.7$ and $39.4{\pm}39.1$ days, respectively. In addition, the 60-day mortality rate after ICU admission was 35.5%. The mean WIC was $2.3{\pm}1.8$, with significant differences between nonsurvivors and survivors ($2.7{\pm}2.1$ vs. $2.1{\pm}1.7$, p<0.05). The area under the curve of receiver-operating-characteristics curve for WIC was 0.593 (95% confidence interval [CI], 0.523-0.661; p<0.05). Based on Kaplan-Meier curves of 60-day survival, WIC ${\geq}5$ had statistically lower survival than WIC <5 (logrank test, p<0.05). In a multivariate Cox proportional hazard model, WIC ${\geq}5$ was associated with poor prognosis (hazard ratio, 1.901; 95% CI, 1.140-3.171; p<0.05). The mortality rate of patients with WIC ${\geq}5$ was 54.2%. Conclusion: Our study showed a WIC score ${\geq}5$ might be helpful in predicting 60-day mortality in PAMV patients.
Under the WTO system, direct export support system that provides financial and tax related support is altogether prohibited. This presented an obstacle in strengthening competitiveness of Korean export business and in increasing exports continuously. One of the methods used to solve this problem was to actively leverage export insurance. In Korea, export insurance services have been conducted by the Korea Trade Insurance Corporation (k-sure) to promote export. Korea has been among the world's active users of the export insurance system. Given this situation, this paper examines the effectiveness of the Korea export insurance system in the promotion of export. In particular, this study analyzed about discriminating effects of the export insurance on the export of big and small-medium business. In order to analyze, We introduce a Export Supply Function model. In this paper, We construct two model. The one is about big business, the other is small-medium business. For empirical analysis, unit-root test was conducted to understand the safety of time series. The results show that all variables are not I(0) time series. Instead, they are I(1) time series. To this, cointegration verification was conducted based on the use of Johansen verification method to define the existence (or non-existence) of long-term balance relationship among variables. The results come out as follows. The export insurance of big business has a stronger effect on export than that of small-medium business. The cause of these results is due to the distinct structure of Korea industries. In view of the fact that the insurance can make the risk decreased. We can say that the export insurance affects the export of a high-risk country.
PURPOSE. This study investigated the strain of implants using a chewing simulator with strain gauges in mandibular implant-supported fixed prostheses under various dynamic loads. MATERIALS AND METHODS. Three implant-supported 5-unit fixed prostheses were fabricated with three different occlusion types (Group I: Canine protected occlusion, Group II: Unilaterally balanced occlusion, Group III: Bilaterally balanced occlusion). Two strain gauges were attached to each implant abutment. The programmed dynamic loads (0 - 300 N) were applied using a chewing simulator (MTS 858 Mini Bionix II systems, MTS systems corp., Minn, USA) and the strains were monitored. The statistical analyses were performed using the paired t-test and the ANOVA. RESULTS. The mean strain values (MSV) for the working sides were 151.83 ${\mu}{\varepsilon}$, 176.23 ${\mu}{\varepsilon}$, and 131.07 ${\mu}{\varepsilon}$ for Group I, Group II, and Group III, respectively. There was a significant difference between Group II and Group III (P < .05). Also, the MSV for non-working side were 58.29 ${\mu}{\varepsilon}$, 72.64 ${\mu}{\varepsilon}$, and 98.93 ${\mu}{\varepsilon}$ for Group I, Group II, and Group III, respectively. One was significantly different from the others with a 95% confidence interval (P < .05). CONCLUSION. The MSV for the working side of Groups I and II were significantly different from that for the non-working side (Group I: t = 7.58, Group II: t = 6.25). The MSV for the working side of Group II showed significantly larger than that of Group III (P < .01). Lastly, the MSV for the non-working side of Group III showed significantly larger than those of Group I or Group II (P < .01).
The study was carried out to suggest on opinion of the standardization of size deviation in the existing raw silk testing method. 1. The present grade A of size deviation stipulates 4.61 to 5.80 of standard deviation for 50 to 69 denier of mean value, however, the 5.80 standard deviation with the mean values of 50 and 69 denier belong to different distribution. 2. It is reasonable that the variation coefficients of grade 2A should be lower than that of grade A. However, the present testing method shows larger variation in grade 2A than in grade A. This is illustrated 9.00 for 69 denier in grade 2A and 8.41 for 70 denier in grade A. 3. The size deviation value compares the quality of raw silk with different mean value. Therefore, the standard deviation is recommended to be replaced by the C.V. value in determining the grade of silk. 4. The C.V. have a tendency to increase with lower grades below 6A for the size deviation below 33 denier with some inconsistencies. The figures should be adjusted so that the C.V. inconsistencies size deviation below 33 denier will be corrected. 5. The standard deviation increases with size under the same grade for the size deviations above 33 denier, however, the C.V. does not vary greatly with size deviation. 6. To rectify the above-mentioned inconsistencies the C.V. conversion and curvilinear regresion correction is recommended to improve the present silk testing method 7. The table of size deviation standard are as follows: Suggested standard of size deviation, unit: C.V. Value
Journal of the Korea Academia-Industrial cooperation Society
/
v.15
no.6
/
pp.3389-3395
/
2014
Conventional methods, such as the clock time control method and temperature difference control method, for defrost control often encounter mal-defrost and a waste of energy. Therefore, a more efficient method is needed to control defrosting precisely. A photoelectric sensor unit consisting of an emitter and a collector was installed in the front of outdoor heat exchanger. Accurate defrost control was performed by monitoring and using the change in output voltage according to the presence of frost. In this study, experiments were performed to determine if the performance and characteristic curves obtained using the clock time control method can be reproduced using a photoelectric sensor under the heating and defrosting capacity test condition described at KS C 9306. The output voltage of the phototransistor (receiver) and heating capacity, power consumption, and surface temperature of the outdoor heat exchanger, were compared. The results showed that photoelectric sensors can be used as a defrost control method. On-off control timing of the clock time defrosting method was in good agreement with those predicted by the output voltage of the photoelectric sensor.
PURPOSE. To evaluate the effects of surface treatments on shear bond strength (SBS) between microwave and conventionally sintered zirconia core/veneers. MATERIALS AND METHODS. 96 disc shaped Noritake Alliance zirconia specimens were fabricated using YenaDent CAM unit and were divided in 2 groups with respect to microwave or conventional methods (n=48/group). Surface roughness (Ra) evaluation was made with a profilometer on randomly selected microwave (n=10) and conventionally sintered (n=10) cores. Specimens were then assessed into 4 subgroups according to surface treatments applied (n=12/group). Groups for microwave (M) and conventionally (C) sintered core specimens were as follows; $M_C$,$C_C$: untreated (control group), $M_1,C_1:Al_2O_3$ sandblasting, $M_2,C_2$:liner, $M_3,C_3:Al_2O_3$ sandblasting followed by liner. Veneer ceramic was fired on zirconia cores and specimens were thermocycled (6000 cycles between $5^{\circ}-55^{\circ}C$). All specimens were subjected to SBS test using a universal testing machine at 0.5 mm/min, failure were evaluated under an optical microscope. Data were statistically analyzed using Shapiro Wilk, Levene, Post-hoc Tukey HSD and Student's t tests, Two-Way-Variance- Analysis and One-Way-Variance-Analysis (${\alpha}$=.05). RESULTS. Conventionally sintered specimens ($1.06{\pm}0.32{\mu}m$) showed rougher surfaces compared to microwave sintered ones ($0.76{\pm}0.32{\mu}m$)(P=.046), however, no correlation was found between SBS and surface roughness (r=-0.109, P=.658). The statistical comparison of the shear bond strengths of $C_3$ and $C_1$ group (P=.015); $C_C$ and $M_C$ group (P=.004) and $C_3$ and $M_3$ group presented statistically higher (P=.005) values. While adhesive failure was not seen in any of the groups, cohesive and combined patterns were seen in all groups. CONCLUSION. Based on the results of this in-vitro study, $Al_2O_{3-}$ sandblasting followed by liner application on conventionally sintered zirconia cores may be preferred to enhance bond strength.
Park, Soo-Ran;Park, Yang-Ho;Park, Young-Ju;Park, Jun-Woo;Lee, Yong-Chan;Ahn, Byoung-Keun
Journal of the Korean Association of Oral and Maxillofacial Surgeons
/
v.28
no.4
/
pp.302-309
/
2002
In order to improve the success rate of implants, various implant designs have been developed. Although there have been enough efforts to handle the surface of the implant with careful choice of material and mechanics so that the bone and the implant can be tightly joined together, they have still failed to play the role of periodontal ligaments of the natural teeth in the past. The role of periodontal ligaments is very important since it can improve the initial stability of implant by absorbing the impacts. The purpose of this study is, thus, to test the possibility of alleviating the impact when the surface of the implant was coated with chitosan, a natural polymer, and making sure that the coated material stayed on. Then, the condition of newly developed bone formation and the degree of inflammation in response was closely observed in the surface level. In the main experiment, Chitosan coated implant ($3.3mm{\times}7mm$) was implanted on both the right and the left side of rabbit's femur. The animals were each sacrificed on the $1^{st}$, $2^{nd}$, $3^{rd}$, $7^{th}$, $14^{th}$, $21^{st}$ and 28th day. The process was observed under an light microscope after the Toluidin Blue staining. From the experiment, it was found that the chitosan was evenly distributed on the surface of the screws, and the implant was adjoined with adjacent bone. There was a sign of inflammation on the $3^{rd}$ day, but on the $14^{th}$ day, the formation of woven bone and newly formed bones were noticed. Also, chitosan filled the gap was formed between the implant and the newly formed bone. The implant, the chitosan and the newly formed bone were forming one unit as a result. Therefore, it was found that chitosan coated implant could absorbe the impact in the initial stage of implant.
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.