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Behavior of Steel Fiber-Reinforced Concrete Exterior Connections under Cyclic Loads (반복하중을 받는 강섬유 보강 철근콘크리트 외부 접합부의 거동 특성)

  • Kwon, Woo-Hyun;Kim, Woo-Suk;Kang, Thomas H.K.;Hong, Sung-Gul;Kwak, Yoon-Keun
    • Journal of the Korea Concrete Institute
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    • v.23 no.6
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    • pp.711-722
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    • 2011
  • Beam-column gravity or Intermediate Moment frames subjected to unexpected large displacements are vulnerable when no seismic details are provided, which is typical. Conversely, economic efficiency of those frames is decreased if unnecessary special detailing is applied as the beam and column size becomes quite large and steel congestion is caused by joint transverse reinforcement in beam-column connections. Moderate seismic design is used in Korea for beam-column connections of buildings with structural walls, which are to be destroyed when the unexpected large earthquake occurs. Nonetheless, performance of such beamcolumn connections may be substantially improved by the addition of steel fibers. This study was conducted to investigate the effect of steel fibers in reinforced concrete exterior beam-column connections and possibility for the replacement of some joint transverse reinforcement. Ten half-scale beam-column connections with non-seismic details were tested under cyclic loads with two cycles at each drift up to 19 cycles. Main test parameters used were the volume ratio of steel fibers (0%, 1%, 1.5%) and joint transverse reinforcement amount. The test results show that maximum capacity, energy dissipation capacity, shear strength and bond condition are improved with the application of steel fibers to substitute transverse reinforcement of beam-column connections. Furthermore, several shear strength equations for exterior connections were examined, including the proposed equation for steel fiber-reinforced concrete exterior connections with non-seismic details.

Effects of Total Sleep Deprivation on Fine Motor Performance (전수면박탈이 정상인의 미세운동수행 능력에 미치는 영향)

  • Lee, Heon-Jeong;Song, Hyung-Seok;Ham, Byung-Joo;Suh, Kwang-Yoon;Kim, Leen
    • Sleep Medicine and Psychophysiology
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    • v.8 no.2
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    • pp.129-137
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    • 2001
  • Objectives: The purpose of this study is to investigate the effects of 38-hour sleep deprivation on fine motor performance. The Motor Performance Series (MPS) in the Vienna Test System (computerized neurocognitive function tests) was used in this study. Methods: Twenty four subjects participated in this study. Subjects had no past history of psychiatric disorders and physical illness. Subjects had normal sleep-waking cycle without current sleep disturbances and were all right-handed (Annett's Hand Preference Questionnaire: above +9 points). To minimize the learning effects, familiarization with the Vienna Test System was performed one day before the study. Subjects were to get up at 6:00 in the morning after getting enough sleep according to his or her usual sleep-wake cycle. After awakening, subjects remained awake for 38 hours under continuous surveillance. During two consecutive study days, the subjects tested MPS at 7 AM and 7 PM each day, which means the MPS was done four times in total. During the experiment, anything that could affect the subjects' sleep such as coffee, tea, alcohol, a nap, tiring sports, and all medications were prohibited. Results: In MPS, the fine motor functions of both hands decreased after 38 hours of sleep deprivation. The decrement in motor performance was prominent in the dominant right hand. In the right hand, the total number of tapping was reduced (p<.005), and the number of misses (p<.05) and the length of misses (p<.05) of line tracking, the total length of inserting a short pin (p<.01), the total length of inserting a long pin (p<.05), and the number of misses in aiming (p<.05) increased. Such performance decrement was distinct in the morning sessions. Conclusions: These results suggest that fine motor performance decrement during sleep deprivation is predominant in the right hand, which exerts maximal motor function. The finding of decrement in motor function in tapping during sleep deprivation also suggested that the time required for exhaustion of muscles is shortened during sleep deprivation. More deterioration of motor performance was shown in the morning, which could be explained as circadian rhythm effects.

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A Study on e-B/L Korea Service and its Facilitation Strategies (한국형 전자선하증권 활성화 전략에 관한 연구)

  • Jeong, Yoon-Say
    • International Commerce and Information Review
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    • v.13 no.4
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    • pp.51-79
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    • 2011
  • Korea has accomplished the establishment of the National Single Window for Paperless Trade. Since 1991, it has developed Trade Automation Service System based on EDI technology. In 2003, Korean government and private sectors jointly began to set up National Paperless Trade Service( e-Trade Service) as one of the e-government projects. In 2008, they commenced the uTradeHub Service which was equipped with Internet based e-B/L and e-Nego service systems for the first time in the world To facilitate the service Korea amended its e-Trade facilitation Act and Law by 2007. At the end of 2011, Korea historically recorded its trade volume of 1 trillion US dollars and joined '$1 trillion trade club' as the 9the member country since the country had started international trade less than five decades ago. A rolling out of the e-B/L and e-Nego service will 'ally reduce the transaction costs of trading businesses and accelerate the activation e-trade services. The purposes of the study are to examine 'e-B/L Korea' service and its facilitation strategies as well as identify obstacles to utilize the 'e-B/L Korea' service. The paper reviewed and analyzed Korea's Paperless trade system and distinctive characteristics of the 'e-B/L Korea Service. Parts of the fOWld distinctive characteristics of the Korea's e-B/L service are as follows; It is well equiped with IT and legal system. It also has more that 30,000 potential users who are already uTradeHub service users. The paper indicated several weaknesses of the current system such as global KPI issues, circulation of the electronic documents not only in the domestic market but also among economies, development of the electronic Bill of Exchange. As resolution measures, the paper recommended the introduction of mutual recognition system of PKI among trade partner counties, setting up e-trade solution for small and medium companies, and special attention to raise users' awareness of the e-B/L service.

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The Comorbidity of Periodic Limb Movements Disorder in Patients with Sleep-Related Breathing Disorder (수면관련 호흡장애 환자에서의 수면중 주기성 사지운동장애의 동반이환율)

  • Yang, Chang-Kook;Son, Choon-Hee
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.5
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    • pp.1039-1046
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    • 1998
  • Background: Sleep-related breathing disorders(SRBD) and periodic leg movements disorder(PLMD) are both common, and are considered as separate sleep disorders. However, both disorders show high comorbidity. SRBD and PLMD can result in excessive daytime sleepiness and insomnia due to frequent sleep fragmentation. So, it is very important to consider the presence of PLMD, when we are dealing with the diagnosis and management of SRBD. The objectives of this study were to determine the incidence of PLMD in patients with SRBD, and to describe any differences between patients with and without PLMD. Method: The authors reviewed the sleep recordings of 106 patients with a final diagnosis of SRBD(obstructive sleep apnea or upper airway resistance syndrome), who underwent full nocturnal polysomnography, including the monitoring of the anterior tibialis electromyogram. All sleep records were recorded and scored using the standard criteria. The data was analyzed by the student t-test. Result: 106 patients(M=76, F=30) were included in the analysis. Data revealed a mean age of $49.5{\pm}13.6$ years, a respiratory disturbance index(RDI) of $22.3{\pm}25.4$/hour sleep, a lowest oxygen saturation of $84.9{\pm}11.3%$, a maximal esophageal pressure of $-41.0{\pm}19.1cmH_2O$, and PLM index(PLMI) of $13.1{\pm}22.4$movements/hour sleep. Forty four percent(47 of 106 patients) had a PLMI of greater than 5 on this study. The mean age of the patients with PLMD was significantly higher than that of the patients without PLMD(p<0.005). Female patients with SRBD accompanied more PLMD(p<0.05). The apnea index of the patients with PLMD was significantly lower than that of the patients without PLMD(p<0.01). The percentage of stage 1 sleep in the patients with PLMD was significantly lower than that of the patients without PLMD(p<0.05). Conclusion: The prevalence of PLMD in the patients with SRBD was high at 44.3%. The patients with PLMD were older and had more high RDI in comparison to the patients without PLMD, which was consistent with previous findings. The authors recommend that more careful consideration of PLMD is required when diagnosing and treating SRBD.

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Comparison of chewing ability and quality of life before and after the dental implantation (임플란트 시술환자의 시술 전.후의 저작능력과 삶의 질 비교)

  • Kim, Kyeong-Won;Lee, Kyeong-Soo;Kang, Pock-Soo;Kim, Woo-Shik;Lee, Hee-Kyeong
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.2
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    • pp.215-221
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    • 2009
  • Statement of problem: Recently the populations of patients receiving implant surgery are greatly increase for maintaining oral health. Purpose: This study was conducted for implanted patients to assess the chewing ability patient satisfaction level and changes in quality of life before and after the implant surgery. Material and methods: The current study subjected 109 adult patients, older than 20 years of age, who received implant surgery from December, 2006 to October, 2007 at the 6 dental clinics located at Daegu and Ulsan metropolitan cities. Twice of surveys were conducted for the patients before and after receiving the dental implant surgery. Results: As the motivation of receiving implant surgery, 45.9% of the patients selected the surgery for the chance o "f chewing function recovery", and " failure of treatment and complications" was found to be the most worrisome at the time of surgery by recording 38.5%.The satisfaction level before the implant surgery scored 30.37, while the score was increased to 45.01 after the surgery by showing a significant difference before and after receiving the surgery(P<.001). Regard on the surgery, 91.8% of the patients responded as "Satisfy", and 89% of the study subjects responded that they have willingness to recommend the surgery to their families and friends. The chewing ability score measured by using the surveys on edible foods, the score before the surgery was 15.24, while the score was increased to 19.11 after the surgery by showing a significant difference before and after receiving the surgery(P<.001). The quality of life score was also found to be increased to 11.17 after the surgery from 9.99 before the surgery by showing a significant difference(P<.001). Conclusion: In a future, the studies on the numbers of implanted loss teeth and the location of tooth loss are necessary, more long-term follow study are needed, and it is thought to be necessary to enlarge the sample size of subjects in conducting the studies.

Identification of Quaternary Faults and shallow gas pockets through high-resolution reprocessing in the East Sea, Korea (탄성파 자료 고해상도 재처리를 통한 동해해역의 제4기 단층 및 천부 가스 인지)

  • Jeong, Mi Suk;Kim, Gi Yeong;Heo, Sik;Kim, Han Jun
    • Journal of the Korean Geophysical Society
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    • v.2 no.1
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    • pp.39-44
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    • 1999
  • High-resolution images are drawn from existing seismic data which were originally obtained by Korea Ocean Research & Development Institute (KORDI) during 1994-1997 for deep seismic studies on the East Sea of Korea. These images are analyzed for mapping Quaternary faults and near-bottom gas pockets. First 12 channels are selected from shot gathers for reprocessing. The processing sequence adopted for high-resolution seismic images comprises data copy, trace editing, true amplitude recovery, common-midpoint sorting, initial muting, prestack deconvolution, bandpass filtering, stacking, highpass filtering, poststack deconvolution, f-x migration, and automatic gain control (AGC). Among these processing steps, predictive deconvolution, highpass filtering, and short window AGC are the most significant in enhancement of resolution. More than 200 Quaternanry faults are interpreted on the migrated sections in the shallow depths beneath the seafloor. Although numerous faults are found mostly at the western continental slope and boundaries of the Ulleung Basin, significant amount of the faults are also indicated within the basin. Many of these faults are believed to be formed with reactivation of basement, from geotectonic activities including volcanism, and often originated in Tertiary, indicating that the tectonic regime of the East Sea might be unstable. Existence of shallow gas pockets casts real hazardous warnings to deep-sea drillings and/or to underwater constructions such as inter-island cables and gas pipelines. On the other hand, discovery of these gas pockets heightens the interests in developing natural resources in the East Sea. Reprocessed seismic sections, however, show no typical seismic characteristics for gas hydrates such as bottom-simulating reflectors in the western continental slope and ocean floor.

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PROSPECTIVE CLINICAL EVALUATION OF THREE DIFFERENT BONDING SYSTEMS IN CLASS V RESIN RESTORATIONS WITH OR WITHOUT MECHANICAL RETENTION (접착제와 와동형성의 차이에 따른 5급 복합레진 수복의 전향적 임상연구)

  • Lee Kyung-Wook;Choung Sae-Joon;Han Young-Chul;Son Ho-Hyun;Um Chung-Moon;Oh Myoung-Hwan;Cho Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.31 no.4
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    • pp.300-311
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    • 2006
  • The purpose of this study is to evaluate prospectively the effect of different bonding systems and retention grooves on the clinical performance of resin restorations in non-carious cervical lesions (NCCLs). Thirty-nine healthy adults who had at least 2 NCCLs in their premolar areas were included in this study. One hundred and fifty teeth were equally assigned to six groups: (A) Scotchbond Multi-Purpose (SBMP, 3M ESPE, St. Paul, MN, USA, 4th generation bonding system) without retention grooves; (B) SBMP with retention grooves; (C) BC Plus (Vericom Co., Anyang, Gyeonggido, Korea, 5th generation bonding system) without retention grooves; (D) BC Plus with retention grooves; (E) Adper Prompt (3M ESPE, Seefeld, Germany, 6th generation bonding system) without retention grooves; (F) Adper Prompt with retention grooves. All cavities were filled with a hybrid composite resin. Denfil (Vericom Co., Anyang, Gyeonggido, Korea) by one operator. Restorations were evaluated at baseline and at 6-month recall, according to the modified USPHS (United States Public Health Service) criteria. Additionally, clinical photographs were taken and epoxy resin replicas were made for SEM evaluation. At 6-month recall, there were some differences in the number of alpha ratings among the experimental groups. But, despite the differences in the number of alpha ratings, there was no significant difference among the 3 adhesive systems (p < 0.05). There was also no significant difference between the groups with or without mechanical retention (p < 0.05). Follow-ups for longer periods than 6 months are needed to verify the clinical performance of different bonding systems and retention grooves.

A Study for an Educational Direction in Fashion Design Subjected to Digital Environment I (디지털 환경에 따른 패션분야의 디자인 교육방향 연구 I)

  • 이미량
    • Archives of design research
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    • v.12 no.4
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    • pp.33-44
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    • 1999
  • Fashion is subjected to newness and change by itself. Fashion trend and tendency which could predict next season akeady indicated that digital and cybel11ation environment lliould be factors in fashion. Changes in future life styles and values caused by digital environment must be variables as fashion objects by themselves. Therefore digital environment of a fashion itself and that all encountered in fashion will not only be an existing situation but also an objective and a factor which must be pursued with fashionable sense in future fashion. Advanced technology and social change in relation to digital environment requires that educational method as well as its content will be changed on the scene of education for future. Thus we should seek an educational direction in fashion design for future society in which digital environment requires new paradigm. Subject to these backgrounds this study has an intension to study the change in fashion extensively influenced by expanded digital environment on a limited situational level of fashion design education and to suggest an educational direction for professional in future fashion design who will serve as a core of fashion area in the future. It is essential that education of professional in fashion for future should be achieved by digital-minded level that eagerly understands and accepts future society in which digital environment will be a main axis. It is necessary for this to make them expetience computers, digital media including CAD program. We have to note that education of digital media is more effective and applicable when accomplished in CAI level which can be related and expetienced with fashion education rather than mere functional training in media themselves. Intellectual creativity will be a vety source of producing values and national competence in 21st centtury. Education of design professional in fashion area must positively accept these environmental charactetistics in future society, as well as deeply reflect the education for the future.

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The Effects of Dietary Supplementation of Feather Meal Digests on the Performances and Muscular Taurine Contents in Broiler Chickens (육계 사료내 우모 Digest 첨가시 생산성과 계육내 Taurine 함량에 미치는 영향)

  • Lee, S.M.;Lim, H.S.;Kim, W.Y.;Paik, I.K.
    • Journal of Animal Science and Technology
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    • v.46 no.5
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    • pp.753-762
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    • 2004
  • its digests on the performance of broiler chicks and taurine content in broiler meat. A total of 100 broiler chickens were assigned to five dietary treatments; Control, PM diet(FM), NaOH treated FM diet(NaOH-FM), HN03 treated FM diet(HN03 - FM) and 0.5% synthetic taurine supplemented diet(Taurine). Treated diets were supplemented with FM or FM digests at the level of 5% to the control diet Treated diets were fed during the last 3wks of 6wks feeding. During the finisher period, weight gain of chicks fed FM treatments tended to decrease in general. Feed intakes of FM and Taurine were significantly lower than the control but were not significantly different from NaOH - FM or HN03- PM. Feed conversion rate(feed intake/gain) of NaOH-FM was significantly higher than those of FM and HNOJ - FM but not different from those of the control and Taurine. Taurine content of the control was highest in heart muscle(1482 J1.g/g) followed by leg muscle(778f.lg/g) and breast muscle(79 J1.g/g). Taurine contents of leg and breast muscle were significantly(P< 0.01) affected by treatments but that of heart muscle was not. Taurine content of Taurine treatments was highest in both leg and breast muscle. Taurine content of leg muscle was increased 170"10 by Taurine supplementation, 123% by FM supplementation, 122% by NaOH - FM supplementation and 63% by HNOJ- FM supplementation compared with control. Taurine content of breast muscle of Taurine treatment was 246% higher than the control, but other treatments were not different from the control. In conclusion, supplementation of feather meal at 5% level of broiler diet can enrich taurine content of leg muscle. Chemical treatments of FM were not effective in improving taurine enrichment of broiler meat.

Effect of n-3 fatty acid deficiency on fatty acid compositions of nervous system in rats reared by artificial method. (N-3 지방산 결핍이 혈청 및 신경조직의 지방산 조성에 미치는 영향)

  • Lim, Sun-Young
    • Journal of Life Science
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    • v.17 no.5 s.85
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    • pp.634-640
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    • 2007
  • Our previous study suggested that n-3 fatty acid deficiency was associated with significantly reduced spatial learning as assessed by Morris water maze test. Here we investigated an effect of n-3 fatty acid deficiency on rat brain, retina and serum fatty acyl compositions at 15 wks age using a first generational artificial rearing technique. Newborn Rat pups were separated on day 2 and assigned to two artificial rearing groups or a dam-reared control group. Pups were hand fed artificial milk via custom-designed nursing bottles containing either 0.02%(n-3 Deficient) or 3.1% (n-3 Adequate) of total fatty acids as a-linolenic acid(LNA). At day 21, rats were weaned to either n-3 deficient or n-3 adequate pelleted diets and fatty acid compositions of brain, retina and liver were analyzed at 15 wks age. Brain docosahexaenoic acid(DHA) was lower(58% and 61%, P<0.05) in n-3 deficient in comparison to n-3 adequate and dam-reared groups, receptively, while brain docosapentaenoic acid(DPAn-6) was increased in the n-3 deficient group. In retina and serum fatty acid compositions, the decreased precentage of DHA and increased precentage of DPAn-6 were observed. These results suggested that artificial rearing method can be used to produce n-3 fatty acid deficiency in the first generation and that adequate brain DHA levels are required for optimal brain function.