• Title/Summary/Keyword: Negative group delay

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The Effect of Depressive Symptoms on Cognitive Function in the Elderly: Moderation Effect of Education (노년기 우울이 인지기능에 미치는 영향: 교육의 조절효과)

  • Shin, Minyoung
    • The Journal of the Korea Contents Association
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    • v.20 no.10
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    • pp.458-469
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    • 2020
  • Geriatric depression is associated with pathological changes in the brain and increases the risk of cognitive impairment or dementia. However, high cognitive reserve, such as high education, can delay or minimize clinical manifestations of pathologies involving the brain, so the effect of geriatric depression on cognitive impairment or dementia may vary depending on the education level. In this study, the author analyzed data from the Korean Longitudinal Study of Aging (KLoSA) to examine whether the effect of geriatric depression on cognitive function differed depending on education level. Among the 10,254 subjects registered in the KLoSA, the 4,905 subjects who met the inclusion criteria were analyzed by stepwise regression analysis. The results were as follows: first, depressive symptoms predicted low cognitive function after 12 years; second, the negative effect of depressive symptoms on cognitive function after 12 years was higher in the old adult group than in the young adult group; and third, the effect of age was significant only in the low-educated group. These results suggest that depressive symptoms in low-educated old adults may increase the risk of development of dementia in the long term.

Extraction and Analysis of Construction Phase Risk Factors in High-rise Construction Project (초고층 건설공사 시공단계 리스크 요인 도출 및 분석)

  • Kim, Sooyong;Kim, Sunghyun;Yang, Jinkook
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.2
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    • pp.90-98
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    • 2016
  • High-rise buildings construction project have various risk factors. Major risk factors are negative results such as time delay and increase of costs. Therefore, this study was analyzed risk factors in construction stages of high-rise buildings using by PROMETHEE technique. For this, this research were identified risk factors through experts Focus Group Interview(FGI). And, PROMETHEE was used to setup evaluation standard for analysis of high-rise building construction risks. Next, the standard of evaluation index calculation was composed by using the definition level in PDRI. Preference function and evaluation index were identified through questionnaires. Through these processes, this study has calculated the importance of high-rise building construction risks using by PROMETHEE technique. As a result, high degree risk factors were as following. These are 'Operation plan of material lifting', 'Outrigger & Belt Truss Construction', 'Foundation work plan of high-rise building' and 'Considering a Structure concept of high-rise building'.

Association of Knowledge and Cultural Perceptions of Malaysian Women with Delay in Diagnosis and Treatment of Breast Cancer: a Systematic Review

  • Khan, Tahir Mehmood;Leong, Jamie Pik Yan;Ming, Long Chiau;Khan, Amer Hayat
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.13
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    • pp.5349-5357
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    • 2015
  • Background: Breast cancer is the most common cancer and the leading cause of cancer mortality among women of all ethnic and age groups in Malaysia. Delay in seeking help for breast cancer symptoms is preventable and by identifying possible factors for delayed diagnosis, patient prognosis and survival rates could be improved. Objectives: This narrative review aimed to understand and evaluate the level of in-depth breast cancer knowledge in terms of clinical breast examination and breast self-examination, and other important aspects such as side-effects and risk factors in Malaysian females. Since Malaysia is multicultural, this review assessed social perceptions, cultural beliefs and help-seeking behaviour in respect to breast cancer among different ethnic groups, since these may impinge on efforts to 'avoid' the disease. Materials and Methods: A comprehensive literature search of seven databases was performed from December 2015 to January 2015. Screening of relevant published journals was also undertaken to identify available information related to the knowledge, perception and help-seeking behaviour of Malaysian women in relation to breast cancer. Results: A total of 42 articles were appraised and included in this review. Generally, women in Malaysia had good awareness of breast cancer and its screening tools, particularly breast self-examination, but only superficial in-depth knowledge about the disease. Women in rural areas had lower levels of knowledge than those in urban areas. It was also shown that books, magazines, brochures and television were among the most common sources of breast cancer information. Delay in presentation was attributed mainly to a negative social perception of the disease, poverty, cultural and religion practices, and a strong influence of complementary and alternative medicine, rather than a lack of knowledge. Conclusions: This review highlighted the need for an intensive and in-depth breast cancer education campaigns using media and community health programmes, even with the existing good awareness of breast cancer. This is essential in order to avoid misconceptions and to frame the correct mind-set about breast cancer among women in Malaysia. Socio-cultural differences and religious practices should be taken into account by health care professionals when advising on breast cancer. Women need to be aware of the risk factors and symptoms of breast cancer so that early diagnosis can take place and the chances of survival improved.

Preventive Priority Methods Based on the Analysis of Fire Accident Causes in Construction Site (건설현장 화재 발생 요인 분석에 따른 예방우선순위 연구)

  • Kim, Hee-su;Jang, Sang-chul;Joo, Jin-gyu
    • Journal of the Korea Institute of Construction Safety
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    • v.2 no.2
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    • pp.50-55
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    • 2019
  • Currently, safety management is becoming important at domestic construction sites. Despite the importance of safety management, accidents at construction sites are steadily increasing. Fire accidents among safety accidents cause not only negative effects on schedule delay or work plans at construction sites, but also huge casualties. Therefore, the purpose of this research is to extract the causes of fire at the construction site through the case of fire at the construction site, and to prioritize prevention through the analysis of the factors to contribute to the prevention of fire. As a research method, we select fire factors through case, conduct surveys through expert group, and analyze survey through AHP technique. The results of the AHP analysis of the survey of expert groups showed that the workers and their sub-item ranked high. Therefore, the priority for fire prevention was given, and this research is believed to help prevent fire.

Design and Evaluation of NACK Based Reliable Multicast Protocol (NACK 기반 신뢰적 멀티캐스트 프로토콜의 설계 및 평가)

  • Jung Sun-Hwa;Park Seok-Cheon
    • Journal of Internet Computing and Services
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    • v.4 no.3
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    • pp.47-55
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    • 2003
  • Multicast protocols ore developed in order to support group communications efficiently, However. there still exist some issues to be solved for deploy multicast protocol in the public internet. This paper refers problem of existing Reliable Multicast Protocols and redesigns component function, and proposes enhanced reliable multicast transport protocol, This paper proposed a improved multicast transport scheme in NACK based reliable multicast. This scheme is much faster than by sender-initiated or receiver-initiated recovery and latency is smaller. Designed components are implemented in UNIX environment using C programming longuage. Then the protocol was evaluated performance through simulation. As the result, proposed protocol is better than existing protocols in both of transmission delay and packet loss. Especially, proposed protocol in this paper con be used in multicast services needed high reliability.

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The Effects of Priming Emotion among College Students at the Processes of Words Negativity Information (유발된 정서가 대학생의 부정적 어휘정보 처리에 미치는 효과)

  • Kim, Choong-Myung
    • Journal of Convergence for Information Technology
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    • v.10 no.10
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    • pp.318-324
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    • 2020
  • The present study was conducted to investigate the influences of emotion priming and the number of negation words on the task of sentential predicate reasoning in groups with or without anxiety symptoms. 3 types of primed emotions and 2 types of stimulus and 3 conditions of negation words were used as a within-subject variable. The subjects were instructed to make facial expressions that match the directions, and were asked to choose the correct answer from the given examples. Mixed repeated measured ANOVA analyses on reaction time first showed main effects for the variables of emotion, stimulus, number of negation words and anxiety level, and the interaction effects for the negation words x anxiety combination. These results are presumably suggested to reflect that externally intervening emotion works on language comprehension in a way that anxiety could delay task processing speed regardless of the emotion and stimulus type, meanwhile the number of negation words can slower language processing only in a anxiety group. Implications and limitations were discussed for the future work.

Femtosecond Mid-IR Cr:ZnS Laser with Transmitting Graphene-ZnSe Saturable Absorber

  • Won Bae Cho;Ji Eun Bae;Seong Cheol Lee;Nosoung Myoung;Fabian Rotermund
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.738-744
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    • 2023
  • Graphene-based saturable absorbers (SAs) are widely used as laser mode-lockers at various laser oscillators. In particular, transmission-type graphene-SAs with ultrabroad spectral coverage are typically manufactured on transparent substrates with low nonlinearity to minimize the effects on the oscillators. Here, we developed two types of transmitting graphene SAs based on CaF2 and ZnSe. Using the graphene-SA based on CaF2, a passively mode-locked mid-infrared Cr:ZnS laser delivers relatively long 540 fs pulses with a maximum output power of up to 760 mW. In the negative net cavity dispersion regime, the pulse width was not reduced further by inhomogeneous group delay dispersion (GDD) compensation. In the same laser cavity, we replaced only the graphene-SA based on CaF2 with the SA based on ZnSe. Due to the additional self-phase modulation effect induced by the ZnSe substrate with high nonlinearity, the stably mode-locked Cr:ZnS laser produced Fourier transform-limited ~130 fs near 2,340 nm. In the stable single-pulse operation regime, average output powers up to 635 mW at 234 MHz repetition rates were achieved. To our knowledge, this is the first attempt to achieve shorter pulse widths from a polycrystalline Cr:ZnS laser by utilizing the graphene deposited on the substrate with high nonlinearity.

Surgery Alone and Surgery Plus Postoperative Radiation Therapy for Patients with pT3N0 Non-small Cell Lung Cancer Invading the Chest Wall (흉벽을 침범한 pT3N0 비소세포폐암 환자에서 수술 단독과 수술 후 방사선치료)

  • 박영제;임도훈;김관민;김진국;심영목;안용찬
    • Journal of Chest Surgery
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    • v.37 no.10
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    • pp.845-855
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    • 2004
  • Background: No general consensus has been available regarding the necessity of postoperative radiation therapy (PORT) and its optimal techniques in the patients with chest wall invasion (pT3cw) and node negative (N0) non-small cell lung cancer (NSCLC). We did retrospective analyses on the pT3cwN0 NSCLC patients who received PORT because of presumed inadequate resection margin on surgical findings. And we compared them with the pT3cwN0 NSCLC patients who did not received PORT during the same period. Material and Method: From Aug. of 1994 till June of 2002, 22 pT3cwN0 NSCLC patients received PORT-PORT (+) group- and 16 pT3cwN0 NSCLC patients had no PORT-PORT (-) group. The radiation target volume for PORT (+) group was confined to the tumor bed plus the immediate adjacent tissue only, and no regional lymphatics were included. The prognostic factors for all patients were analyzed and survival rates, failure patterns were compared with two groups. Result: Age, tumor size, depth of chest wall invasion, postoperative mobidities were greater in PORT (-) group than PORT (+) group. In PORT (-) group, four patients who were consulted for PORT did not receive the PORT because of self refusal (3 patients) and delay in the wound repair (1 patient). For all patients, overall survival (OS), disease-free survival (DFS), loco-regional recurrence-free survival (LRFS), and distant metastases-free survival (DMFS) rates at 5 years were 35.3%, 30.3%, 80.9%, 36.3%. In univariate and multivariate analysis, only PORT significantly affect the survival. The 5 year as rates were 43.3% in the PORT (+) group and 25.0% in PORT (-) group (p=0.03). DFS, LRFS, DMFS rates were 36.9%, 84.9%, 43.1 % in PORT (+) group and 18.8%, 79.4%, 21.9% in PORT(-) group respectively. Three patients in PORT (-) group died of intercurrent disease without the evidence of recurrence. Few suffered from acute and late radiation side effects, all of which were RTOG grade 2 or lower. Conclusion: The strategy of adding PORT to surgery to improve the probability not only of local control but also of survival could be justified, considering that local control was the most important component in the successful treatment of pT3cw NSCLC patients, especially when the resection margin was not adequate. Authors were successful in the marked reduction of the incidence as well as the severity of the acute and late side effects of PORT, without taking too high risk of the regional failures by eliminating the regional lymphatics from the radiation target volume.

The Effect of Audit Quality on Crash Risk: Focusing on Distribution & Service Companies (감사품질이 주가급락 위험에 미치는 영향: 유통, 서비스 기업을 중심으로)

  • Chae, Soo-Joon;Hwang, Hee-Joong
    • Journal of Distribution Science
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    • v.15 no.8
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    • pp.47-54
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    • 2017
  • Purpose - According to agency theory, managers have incentives to adjust firm revenues to meet earnings expectations or delay bad news disclosure because of performance-based compensation and their reputation in the market. When the bad news accumulates, stock prices fail to reflect all available information. Thus, market prices of stocks are higher than their intrinsic value. After all, bad news crosses the tipping point, it comes out all at once. That results in stock crashes. Auditors can decrease stock crash risk by reducing agency costs through their informational role. Especially, stock price crash risk is expected to be lower for firms adopting high-quality audits. We focus on distribution and service industry to examine the relation between audit quality and stock price crash risk. Industry specialization and auditor size are used as proxies for auditor quality. Research design, data and methodology - Our sample contains distribution and service industry firms listed in KOSPI and KOSDAQ during a period of 2004-2011. We use a logistic regression to test whether auditor quality influences crash risk. Auditor quality was measured by industry specialist auditor and Big4 / non-Big4 dichotomy. Following the approach in prior researches, we use firm-specific weekly returns to measure crash risk. Firms experiencing at least one stock price crash in a specific week during year are classified as the high risk group. Results - The result of analyzing 429 companies in distribution and service industry is summarized as follows: Above all, it is shown that higher audit quality has a significant negative(-) effect on the crash risk. Crash risk is alleviated for firms audited by industry specialist auditors and Big 4 audit firms. Therefore, our results show that hypotheses are supported. Conclusions - This study is very meaningful as the first study which investigated the effects of high audit quality on stock price crash risk. We provide evidence that high-quality auditors reduce stock price crash risk. Our finding implies that the risk of extreme losses can be reduced through screening of high-quality auditors. Therefore investors and regulators may utilize our findings in their investment and rule making decisions.

Distributed Amplifier with Control of Stability Using Varactors (가변 커패시터를 이용하여 안정도를 조절할 수 있는 Distributed Amplifier)

  • Chu Kyong-Tae;Jeong Jin-Ho;Kwon Young-Woo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.5 s.96
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    • pp.482-487
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    • 2005
  • In this paper, we propose the control method of output impedance of each cascode unit cell of distributed amplifier by connecting varactors in the gate-terminal of common gate. Compared to common source unit cell, cascode unit cell has many advantages such as high gain and high output impedance as well as negative resistance loading. But if the transistor model which is used in design is inaccurate and process parameter is changed, oscillation sometimes can occur at band edge in which the gain start to drop. Therefore, we need control circuit which can prevent oscillation, although the circuit has already fabricated, and varactor connected to gate-terminal of common gate of cascode gain cell can play that part. Measured result of fabricated distributed amplifier shows the capability of contol of gain characteristic by adjusting of value of varactors, this can guarantee the stability of the circuit. The gain is $8.92\pm0.82dB$ over 49 GHz, the group delay is $\pm9.3 psec$ over 41 GHz. All transistor which has $0.15{\mu}m$ gate length is GaAs based p-HEMT, and distributed amplifier is put together with 4 stages.