• Title/Summary/Keyword: 2 order system

Search Result 14,811, Processing Time 0.045 seconds

Potential Endocrine Disrupting Effects of Phthalates in In Vitro and In Vivo Models

  • Nguyen, Tien-Thanh;Jung, Eui-Man;Yang, Hyun;Hyun, Sang-Hwan;Choi, Kyung-Chul;Jeung, Eui-Bae
    • Journal of Embryo Transfer
    • /
    • v.25 no.4
    • /
    • pp.207-213
    • /
    • 2010
  • Thousands of new chemicals have been introduced to environment during last decades. Many of them and common consumer products have been shown to be the endocrine disrupting chemicals. One such chemical group is the phthalates, used in soft poly vinyl chloride (PVC) material and in a huge number of consumer products. The prevalence of these modem chemicals have a remarkable increase. Approximately 3.5 million tons of the main phthalate, di-(2-ethylhexyl) phthalate (DEHP), are produced annually worldwide and indeed, DEHP is considered a ubiquitous environmental contaminant. It has been demonstrated that high doses of phthalate can adversely affect adult and developing animals. In this review, we critically discuss the conclusions of recently original research papers and provide an overview of studies on reproductive disrupting effects of phthalates. In addition, we review the reproductive toxicity data of phthalates in some in vitro research and in both male and female reproductive systems in experimental and domestic animals. Finally, we point out some critical issues that should be addressed in order to clarify the implication of phthalates for human reproduction.

A Study of the Chosun Dynasty King Hyeonjong's Acupuncture-moxibustion Therapeutic Records (조선 현종대왕의 침구치료기록에 대한 연구)

  • Lee, Sang-Won;Kim, Dong-Ryul;Cha, Wung-Seok
    • Korean Journal of Acupuncture
    • /
    • v.28 no.2
    • /
    • pp.77-86
    • /
    • 2011
  • Objectives : This study is on the acupuncture and moxibustion treatment records of King Hyeonjong, classified according to diseases and chronology. Methods : Records on the acupuncture and moxibustion treatment of King Hyeonjong have been extracted from the web database of "The Daily Records of Royal Secretariat of Chosun Dynasty". First, all articles containing the keywords 'Yakbang (藥房)' and 'Euigwan (醫官)' have been extracted. Then, those during King Hyeonjong's reign have been rearranged in chronological order. Among these records, those regarding acupuncture and moxibustion have been used in this paper. Results : King Hyeonjong was mostly treated on eye diseases, musculoskeletal system disorders, deficient source qi, and tumor. Acupuncture treatment was preferred for eye diseases, and moxibustion treatment for musculoskeletal disorders. Medicine was used 50 times, acupuncture 4 times, and moxibustion 14 times to treat source qi deficiency, showing that acupuncture and moxibustion treatments were used for clear deficiency syndrome. Only on the case of tumor, the number of acupuncture treatments was bigger than that of medicine treatments. Conclusions : In the early days of his reign, King Hyeonjong suffered from hypochondria, as compared to source qi deficiency and septicemia during later days. He received frequent acupuncture and moxibustion treatments, and he especially preferred those treatments for eye diseases and musculoskeletal disorders.

An Automatic Collision Avoidance System for Drone using a LiDAR sensor (LiDAR 센서를 이용한 드론 자동 충돌방지 시스템)

  • Chong, Ui-Pil;An, Woo-Jin;Kim, Yearn-Min;Lee, Jung-Chul
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.19 no.2
    • /
    • pp.54-60
    • /
    • 2018
  • In this paper, we propose an efficient automatic control method for the collision avoidance of drones. In general, the drones are controlled by transmitting to the flight control (FC) module the received PWM signals transmitted from a RC controller which transduce movements of the knob into PWM signal. We implemented the collision avoidance module in-between receiver and FC module to monitor and change the throttle, pitch and roll control signals to avoid drone collision. In order to avoid the collision, a LiDAR distance sensor and a servo-motor are installed and periodically measure the obstacle distance within -45 degrees from 45 degrees in flight direction. If the collision is predicted, the received PWM signal is changed and transmitted to the FC module to prevent the collision. We applied our proposed method to a hexacopter and the experimental results show that the safety is improved because it can prevent the collision caused by the inadvertency or inexperienced maneuver.

Empirical Study on the Causes and Result of Job Stress Among Fire Fighters: Focusing on Job Characteristics, Role Confusion, Relationships with Co-Workesr and Organizational Commitment (소방공무원의 직무스트레스 유발원인과 결과에 관한 실증적 연구: 직무특성, 역할혼돈, 동료관계와 조직몰입을 중심으로)

  • Lee, Sang-Ku;Lee, Yong-Kyu
    • Fire Science and Engineering
    • /
    • v.21 no.2 s.66
    • /
    • pp.74-86
    • /
    • 2007
  • In order to analyze causes and results of job stress among fire fighters, the structural model was developed and reviewed by a survey asking questions about job stress, job commitment role confusion and relationships with co-workers to 961 fire fighters working in Seoul, Korea. Results of research are correspond with previous research results done in different working environment although fire lighters experienced much higher job stress than average public officers. According to research results, both' job character' and 'relationships with co-worker' influenced 'job stress' and 'job commitment' directly at a statistically significant level. 'Role confusion' influenced 'job stress' directly but influenced 'job commitment' indirectly through 'job stress'. Results of this research could be utilized for expressing necessity of building a job stress management system for fire fighters in Korea.

The Histologic Effects of Jungcheonhwadamgangki-tang Extract on the Experimental Asthma induced by ovalbumin (정천화담강기탕(定喘化痰降氣湯)이 ovalbumin으로 유발(誘發)된 천식(喘息)의 조직학적(組織學的) 변화(變化)에 미치는 영향(影響))

  • Lee, Sang-Jun;Park, Ji-Hyeon;Choi, Hae-Yun;Kim, Jong-Dae
    • Herbal Formula Science
    • /
    • v.9 no.1
    • /
    • pp.273-288
    • /
    • 2001
  • Objectives : In order to study the effect of oral administration of Jungcheonhwadamgangki-tang against the asthma. Method : Asthma was induced to Balb/c mouse with ovalbumin by using method of Hatfield et al. It was observed the changes numbers and morphology of the mast cells in the trachea, numbers of mucous secretory cell in the bronchus, morphology of the bronchus, ultramicroscopical appearance of surface of trachea and number of cilia and mucous secretory cells by scanning electron microscope. Result : 1. Degranulation and decreasing of the numbers of mast cells were significantly decreased in the Jungcheonhwadamgangki-tang extract group as compared with control group. 2. Hypertrophy of mucous membrane of bronchus In the lung, infiltration of inflammatory cells, increasing of mucous secretory cells in the bronchus were significantly decreased in the Jungcheonhwadamgangki-tang extract group as compared with control group. 3. Shedding, decreasing of cilia cells and increasing of mucous secretory cells in the surface of the trachea were significantly decreased in the Jungcheonhwadamgangki-tang extract group as compared with control group. Conclusion : It is considered that Jungcheonhwadamgangki-tang has somewhat favorable effects on the asthma because the asthma specific series of abnormalities in respiratory system were decreased after oral administration of Jungcheonhwadamgangki-tang in this study. In future, it is needed that the toxicological and dosage specific study of Jungcheonwhadamgangki-tang to use against bronchial asthma with safe.

  • PDF

Effect of SAENGCHINYANGHYOLTANG on the hepatic metabolic enzyme system in streptozotocin-induced diabetic rats (고혈당(高血糖) 쥐의 간(肝) 대사효소계(代謝酵素系)에 미치는 생진양혈탕(生津養血湯)의 영향(影響))

  • Kim, Shin-Seok;Lee, Kyung-Hee;Lee, Cheol-Whan;Choi, Jong-Won;Kim, Seock-Hwan
    • The Journal of Korean Medicine
    • /
    • v.16 no.2 s.30
    • /
    • pp.320-336
    • /
    • 1995
  • SANGNYANGHYOLTANG(SYT) is one of the most important prescription that has been used in oriental medicine for diabetes mellitus. The sudy was done in order to elucidate the anti-diabetic effect of SYT. After pretreatment of SYT(1,000mg/kg) for 6 weeks, the effect of of SYT was prevented on serum liver function test and hepatic lipid peroxide content in rats i.v. injected with streptozotocin(STZ, 50mg/kg, tail vein) 5 weeks after pretreatment of SYT. The hepatic microsomal cytochrome P-450 and aniline hydroxylase were significantly decreased, and aminopyrine N-demethylase activity was significantly increased in SYT-STZ group as compared with control group. Changes in aldehyde oxidase, xanthine oxidase, superoxide dismutase, catalase, epoxide hydrolase, UDP-glucuronyltransferase and sulfotransferase activities were not significantly different in any of the group. The cytosolic glutathione S-transferase activity was significantly decreased in SYT-STZ group as compared with control group. The selenium-independent glutathione peroxidase was significantly increased in SYT-STZ group as compared with control group, but there was no significant difference in selenium-dependent glutathione peroxidase in any of the groups. The hepatic glutathione concentration was significantly increased in SYT-STZ group as compared with control group, and ${\gamma}-glutamylcystein$ synthetase and glutathione reductase activities were not significantly different in any of the groups. The hepatic lipid peroxide content, serum aminotransferase and sorbitol dehydrogenase activities were slightly decreased in significantly in SYT-STZ groups.

  • PDF

Characteristics of Hydrogen and Carbon Production in Tubluar Reactor by Thermal Decomposition of Methane (Methane의 고온열분해에 의한 Tubluar reactor에서의 수소 및 탄소 생성 특성)

  • Lee, Byung Gwon;Lim, Jong Sung;Choi, Dae Ki;Park, Jeong Kun;Lee, Young Whan;Baek, Young Soon
    • Journal of Hydrogen and New Energy
    • /
    • v.13 no.2
    • /
    • pp.101-109
    • /
    • 2002
  • This work was focused on the thermal decomposition of methane into hydrogen and carbon black without emitting carbon dioxide. Extensive experimental investigation on the thermal decomposition of methane has been carried out using a continuous flow reaction system with tubular reactor. The experiments were conducted at the atmospheric pressure condition in the wide range of temperature ($950-1150^{\circ}C$) and flow rate (250 - 1500 ml/min) in order to study their dependency on hydrogen yield. During the experiments the carbon black was successfully recovered as an useful product. Undesirable pyrocarbon was also formed as solid film, which was deposited on the inside surface of tubular reactor. The film of pyrocarbon in the reactor wall became thicker and thicker, finally blocking the reactor. The design of an efficient reactor which can effectively suppress the formation of pyrocarbon was thought to be one of the most important subjects in the thermal cracking of methane.

Design and Implementation of Multimedia CAI Program for Learning about Electricity in the Mechanics Curriculum (기술과 전기 학습을 위한 멀티미디어 CAI 프로그램 설계 및 구현)

  • Lee, Hyae-Joung;Shin, Hyun-Cheul;Joung, Suck-Tae
    • Convergence Security Journal
    • /
    • v.7 no.2
    • /
    • pp.9-16
    • /
    • 2007
  • In today's society, the paradigm is converted to information where both this and knowledge become the source of value added. In order to answer societies' needs school education is subject to a large change, that is 'from supplier-centered learners to demand-centered learners'. This study is the design and implementation of multimedia CAI program for learning about electricity in the meddle school the mechanics curriculum with a focus in generating electricity. Based on multimedia, software, educational utilization of the multimedia, CAI, learning theory and form, both technology and multimedia elements related to curriculum are analyzed. This title is composed of object, contents, evaluation and related sites every chapter for students to study. Also, it is designed for students to take interest and participate in the learning process actively by combining lots of media such as characters, sound, images and animation. Specially it is composed in a way of repetition according to the student's level.

  • PDF

Public Infrastructure Practitioner's Recognition on Project Performance (공공토목공사 실무자의 성과요인 인식차이 분석)

  • Park, Hee-Sung
    • Korean Journal of Construction Engineering and Management
    • /
    • v.8 no.2
    • /
    • pp.93-100
    • /
    • 2007
  • Performance measurement and evaluation is a critical issue in public funded civil infrastructure projects in recent years. As a results, Korean government has introduced the related policies and regulations based on the foreign cases to evaluate public construction projects. However, construction circumstances are different from other countries and the results from adopted regulations are not satisfied. Therefore this research proposes the critical success factors(schedule, cost, productivity, change order, safety, quality) for public construction projects based on previous related research outputs to successfully implement construction performance evaluation. Then, this paper also proposes the weights for the critical success factors. The proposed weights are developed by AHP of construction experts. Furthermore, the paper shows the difference of the weights of the critical success factors by project participants (owner, constructor, engineering, and inspector). This efforts will enhance the ability to develop an effective performance evaluation process and system for public construction projects.

Korean Longitudinal Study of Ageing: Research Design for International Comparative Studies (고령화연구패널조사의 국제비교연구 활용 가능성)

  • Boo, Ka-Chung;Chang, Ji-Yeun
    • Survey Research
    • /
    • v.7 no.2
    • /
    • pp.97-122
    • /
    • 2006
  • Korean Longitudinal Study of Ageing(KLoSA)', launched in 2006, has developed a research network with 'Health and Retirement Study(HRS, US),' Studies on Health and Retirement in Europe(SHARE, EU),' and 'English Longitudinal Study of Ageing(ELSA, UK)'and tried to construct a mega data library. The KLoSA team has designed their research with focusing on the following three points, in order to use KLoSA for international comparative studies. First, KLoSA shares the key research areas such as family structure, health, employment, income, asset, subjective expectations with the comparable studies. Second, KLoSA team has developed the instrument to reflect the Korean culture and institutions. They considered the institutional characteristics in public pension and health care system and in employment practices. They also counted the cultural conventions in family life such as financial management and care exchange, Finally, KLoSA tries to capture the psychological characteristics of the Korean elderly by making the measurement scales more understandable.

  • PDF