Spacecraft Guidance Algorithms for Asteroid Intercept and Rendezvous Missions

Hawkins, Matt,Guo, Yanning,Wie, Bong The Korean Society for Aeronautical and Space Scie 2012 International Journal of Aeronautical and Space Sc Vol.13 No.2

This paper presents a comprehensive review of spacecraft guidance algorithms for asteroid intercept and rendezvous missions. Classical proportional navigation (PN) guidance is reviewed first, followed by pulsed PN guidance, augmented PN guidance, predictive feedback guidance, Lambert guidance, and other guidance laws based on orbit perturbation theory. Optimal feedback guidance laws satisfying various terminal constraints are also discussed. Finally, the zero-effort-velocity (ZEV) error, analogous to the well-known zero-effort-miss (ZEM) distance, is introduced, leading to a generalized ZEM/ZEV guidance law. These various feedback guidance laws can be easily applied to real asteroid intercept and rendezvous missions. However, differing mission requirements and spacecraft capabilities will require continued research on terminal-phase guidance laws.

MULTINATIONAL CORPORATIONS : THE CHANGED ENVIRONMENT FOR THE 1980s and BEYOND

Hawkins, Robert G. 동국대학교 해외개발연구소 1983 國際貿易論叢 Vol.1 No.-

수로시공의 기계화

Hawkins, G.P. 한국농공학회 1980 한국농공학회논문집 Vol.22 No.1

Site Specific Relationships between Muscle Strength and Mass andBone Mineral Density in Young and Middle-aged Women

Hawkins S. A.,유은정(Eun Jung Yoo) 한국사회체육학회 2010 한국사회체육학회지 Vol.0 No.42

본 연구는 특정 부위별 근력, 근육량, 골밀도와의 관계를 알아보는데 그 목적이 있다. 특히, 특정 부위의 근력이나 근육량이 그 부위의 골밀도와 어떠한 관계가 있는지를 밝히고자 한다. 18명의 일반 여대생(22.1 ± 2.5 yrs)과 20명의 신체활동이 활발한 중년 여성(52.4 ± 6.8 yrs) 등 모두 38명의 피험자가 연구에 참가하였다. Dual energy x-ray absorptiometry(DEXA)로 골밀도와 신체조성을 측정하였고, isokinetic dynamometery를 이용하여 근력을 측정하였다. 여대생과 중년 여성의 대퇴 근력과 근육량의 관계를 측정한 자료 분석 결과에 의하면, 두 집단 모두 대퇴부의 근력과 근육량 사이에 유의한 상관관계가 나타남으로써 연령과 무관함을 설명해주고 있다. 특히, 근력과 근육량은 여대생 그룹에게 있어 특정 부위 골밀도(femur BMD)와 명확한 상관관계를 보여주고 있다(r=.49~.70, p<.05). 하지만, 중년여성에 있어서는 근력, 근육량, 골밀도가 여대생에서 나타나는 패턴을 보여주고 있지 않았다. 이와 같은 근력, 근육량, 골밀도의 두 집단 간 차이는 폐경기 내분비적 변화와 같은 호르몬 요인 및 연령에 의한 근조성의 차이에 의한 것으로 추측되며, 중년 및 노년 여성을 위한 근력운동의 중요성을 지지하는 것으로 사료된다.

Biomechanics, Training & Injury Prevention: Considerations for the Taekwondo Youth Athlete

( David Hawkins ) 국제태권도학회 2014 Journal of the International Association for Taekw Vol.1 No.1

Musculoskeletal injuries are common in many athletic training programs and efforts to limit these injuries are warranted. The purpose of this paper is to: (1) highlight specific biomechanics principles and their relevance to training and injury prevention, (2) summarize research characterizing how various factors affect musculoskeletal structures and injury risk in youth, and (3) synthesize this information into a personalized training prescription model that can be used by those involved in youth Taekwondo. A narrative review of relevant literature is presented, and a personalized training prescription model is developed. Material science concepts and basic research findings related to musculoskeletal injury mechanisms were reviewed along with various injury causation models. The information was synthesized into a personalized training prescription model. The structural/material properties of musculoskeletal structures and the acute and chronic temporal response of these properties to loading vary within and between individuals. Age, sex, and individual genetic differences are factors that influence an athlete`s musculoskeletal responses to training and their risk for incurring acute or overuse musculoskeletal injuries. Thus, different athletes can have different acute and chronic changes to musculoskeletal structural/material properties in response to similar loading histories. These concepts were integrated into a personalized training prescription model. The personalized training prescription model provides a useful guide to assist those involved in Taekwondo to develop training programs that assess and adjust various factors affecting injury risk to ensure young athletes receive the greatest sports experience and life-long health benefits.

Total 25-OH Vitamin D Concentrations in Chinese, Malays and Indians

Robert Hawkins 대한진단검사의학회 2013 Annals of Laboratory Medicine Vol.33 No.2

Managing the Pre- and Post-analytical Phases of the Total Testing Process

Robert Hawkins 대한진단검사의학회 2012 Annals of Laboratory Medicine Vol.32 No.1

For many years, the clinical laboratory’s focus on analytical quality has resulted in an error rate of 4-5 sigma, which surpasses most other areas in healthcare. However, greater appreciation of the prevalence of errors in the pre- and post-analytical phases and their potential for patient harm has led to increasing requirements for laboratories to take greater responsibility for activities outside their immediate control. Accreditation bodies such as the Joint Commission International (JCI) and the College of American Pathologists (CAP) now require clear and effective procedures for patient/sample identification and communication of critical results. There are a variety of free on-line resources available to aid in managing the extra-analytical phase and the recent publication of quality indicators and proposed performance levels by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) working group on laboratory errors and patient safety provides particularly useful benchmarking data. Managing the extra-laboratory phase of the total testing cycle is the next challenge for laboratory medicine. By building on its existing quality management expertise, quantitative scientific background and familiarity with information technology, the clinical laboratory is well suited to play a greater role in reducing errors and improving patient safety outside the confines of the laboratory.

Bus headway optimization with consumer surplus as a measure of societal benefit

Jason Hawkins,S. C. Wirasinghe,J. D. Hunt 서울시립대학교 도시과학연구원 2021 도시과학국제저널 Vol.25 No.1

This paper derives the square root bus dispatch optimization developed by Newell from consumer surplus rather than the original cost minimization function. We then extend the model to consider dispatch-variant demand and outline its property relative to the original model by Newell. Demand elasticity is introduced via a multinomial logit mode choice model. Results are tested for City of Edmonton mode choice and ridership. The sensitivity of the function to wait time cost and passenger demand is tested. For the observed passenger demand and value of travel time, our analysis suggests there is a portion of riders who are captive and will suffer increasing wait time costs, but many passengers will make the choice to utilize other modes of travel when faced with increasing bus headways.

Spacecraft Guidance Algorithms for Asteroid Intercept and Rendezvous Missions

Matt Hawkins,Yanning Guo,Bong Wie 한국항공우주학회 2012 International Journal of Aeronautical and Space Sc Vol.13 No.2

This paper presents a comprehensive review of spacecraft guidance algorithms for asteroid intercept and rendezvous missions. Classical proportional navigation (PN) guidance is reviewed first, followed by pulsed PN guidance, augmented PN guidance, predictive feedback guidance, Lambert guidance, and other guidance laws based on orbit perturbation theory. Optimal feedback guidance laws satisfying various terminal constraints are also discussed. Finally, the zero-effort-velocity (ZEV) error, analogous to the well-known zero-effort-miss (ZEM) distance, is introduced, leading to a generalized ZEM/ZEV guidance law. These various feedback guidance laws can be easily applied to real asteroid intercept and rendezvous missions. However, differing mission requirements and spacecraft capabilities will require continued research on terminal-phase guidance laws.

New Biomarkers of Acute Kidney Injury and the Cardio-renal Syndrome

Robert Hawkins 대한진단검사의학회 2011 Annals of Laboratory Medicine Vol.31 No.2

Changes in renal function are one of the most common manifestations of severe illness. There is a clinical need to intervene early with proven treatments in patients with potentially deleterious changes in renal function. Unfortunately progress has been hindered by poor definitions of renal dysfunction and a lack of early biomarkers of renal injury. In recent years, the definitional problem has been addressed with the establishment of a new well-defined diagnostic entity, acute kidney injury (AKI), which encompasses the wide spectrum of kidney dysfunction, together with clearer definition and sub-classification of the cardio-renal syndromes. From the laboratory have emerged new biomarkers which allow early detection of AKI, including neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C. This review describes the new concepts of AKI and the cardio-renal syndromes as well as novel biomarkers which allow early detection of AKI. Panels of AKI biomarker tests are likely to revolutionise the diagnosis and management of critically ill patients in the coming years. Earlier diagnosis and intervention should significantly reduce the morbidity and mortality associated with acute kidney damage.