Homoepitaxial ZnO Thin Films Fabricated by Using Pulsed-Laser Deposition

Holger von Wenckstern,Matthias Brandt,Heidemarie Schmidt,Christian Hanisch,Gabriele Benndorf,Holger Hochmuth,Michael Lorenz,Marius Grundmann 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

ZnO thin films were deposited homoepitaxially by using pulsed-laser deposition on ZnO wafers grown by using the hydrothermal method. The dominant shallow donor level in the nominally undoped thin films is AlZn, as suggested by thermal admittance spectroscopy and low temperature photoluminescence measurements. The homoepitaxial ZnO:P thin films are n-conducting in the as-grown state, which facilitates investigations by Hall effect measurements. The Hall mobility of such ZnO:P thin lms is higher than that of heteroepitaxial ZnO thin lms and its temperature dependence is similar to that of ZnO single crystals grown by seeded chemical vapor transport.

Rejoinder: A general approach to D-optimal designs for weighted univariate polynomial regression models

Holger Dette,Matthias Trampisch 한국통계학회 2010 Journal of the Korean Statistical Society Vol.39 No.1

A general approach to D-optimal designs for weighted univariate polynomial regression models

Holger Dette,Matthias Trampisch 한국통계학회 2010 Journal of the Korean Statistical Society Vol.39 No.1

We study the D-optimal design problem for the common weighted univariate polynomial regression model with efficiency function . We characterize the efficiency functions for which an explicit solution of the D-optimal design problem is available based on a differential equation for the logarithmic derivative of the efficiency function. In contrast to the common approach which starts with a given efficiency function and derives a differential equation for the supporting polynomial of the D-optimal design, we derive a differential equation for the efficiency function, such that an explicit solution of the Doptimal design problem is possible. The approach is illustrated for various convex design spaces and is depicted in several new examples. Also, this concept incorporates all classical efficiency functions discussed in the literature so far.

An analysis of the COVID-19 pandemic’s impact on the lives of international students with a focus on the situation in Germany

Holger Preut 글로벌교육연구학회 2021 글로벌교육연구 Vol.13 No.1

본 연구는 독일의 상황을 중심으로 COVID-19 대유행이, 해외 거주중인 유학생들의삶에 어떤 영향을 미쳤는지에 대해 연구하였다. 이 연구결과는 COVID-19 바이러스확산을 막기 위한 사회 봉쇄가 전 세계 유학생들의 사회적 고립, 정서적 고통, 재정적어려움을 악화시켰다는 것을 보여준다. 사회 봉쇄와 캠퍼스 폐쇄가 계속되는 동안, 이연구의 초점인 독일 내 외국인 유학생들은 사회적 고립과 직업상실로 인한 경제적 어려움, 그리고 학업 중퇴에 대한 불안, 거주 신분과 관련된 두려움으로 고통받고 있다. 독일 내 거주 중인 개발도상국가 유학생들의 경우, 건강과 안전에 대한 우려보다는독일의 경제 상황에 대한 불안과 취업 전망에 대한 우려가 더 높았다. COVID-19 대유행기간 동안 독일 내 외국인 유학생들이 직면했던 수많은 어려움에도 불구하고, 해외 유학장소로서 매력이 지속된다면, 독일로의 유학생이동성(ISM) 회복이 가능할 것이다. 이것은 또한 COVID-19 대유행 기간 동안 독일내 유학생들이 받는 지원의 질과 관련이있을 것이다. Focusing on the situation in Germany, this study examines how the COVID-19 pandemic has impinged on the lives of international students in their host countries. The findings reveal that COVID-19 virus protection measures have aggravated the social isolation, emotional distress, and financial hardship of international students worldwide. Whilst lockdowns and campus closures continue, international students in Germany suffer from growing social isolation, loss of student jobs, fear related to a potential dropout from studies, and a likely loss of resident status. For international students from developing countries, concerns about financial insecurity and poor job prospects in Germany seem more pressing than health and safety concerns. Despite the numerous challenges faced by international students during the pandemic, a revival of previous inbound student mobility growth to Germany is possible, if perceptions of Germany as an attractive overseas study destination sustain. This will also depend on the quality of support international students in Germany receive during the pandemic.

금융개방의 정책적 교훈 : 자본계정 자유화의 비용과 편익 : 뉴질랜드의 경험

(Holger Wolf) 한국금융연구원 1994 정책조사보고서 Vol.94 No.1

Recent research results on human health hazards caused by food-related microplastics

Holger Sieg,Albert Braeuning 환경독성보건학회 2021 한국독성학회 심포지움 및 학술발표회 Vol.2021 No.5

The German Federal Institute for Risk Assessment (BfR) is a scientific institution within the portfolio of the Federal Ministry of Food and Agriculture (BMEL) in Germany. It advises the Federal Government on questions of food, chemical and product safety. The BfR conducts its own research on topics that are closely linked to its assessment tasks. The Food Safety Department assesses the substance risks from food. The substances for assessment may be contained naturally as ingredients in food or may be admixed to food as additives or flavourings. Undesirable substances, which reach food during manufacturing, storage or treatment processes, are also evaluated. This includes also micro- and nanoplastics. The topic of micro- and nanoplastics gained much public attention, since it has been discovered recently that microplastic particles reach the human gastrointestinal tract via food products. Microplastics is defined as polymer particles of different materials in a size range between 1 μm (0.001 mm) and 5 mm. Although, methodological challenges still exist for these particles, there have been scientific investigations, to get a clearer view on its intestinal toxicity. Particles bigger than 1.5 μm are unlikely to be bioavailable and effects are only detected in overload situations, decades above realistic exposure scenarios. The situation for particles smaller than 1 μm, however, is much more challenging. The BfR conducts research projects to compare microplastic particles of food-relevant materials (polyvinylchloride, melamin resin, metacrylate, polylactic acid, polystyrene) with particles with sizes below 1 μm, down to 25 nm. Cellular particle uptake and transport over the intestinal barrier as well as toxicological mechanisms are investigated using human in vitro cell models. Aim is the quantification of cellular uptake and the investigation of possible mechanisms which could have an impact on human health, to achieve a better understanding of the risks which could be caused by submicron- and nanoplastic particles. A special focus lies on the material differences between the broad spectrum of different plastic materials. According to experiences from nanotoxicology, an increased uptake and biodistribution can be possible for smaller particles in the submicron- and nano-range. While no intentionally produced nanoplastics are known, it is plausible that these particles can emerge from bigger plastic particles by weathering and decomposition, although quantitative investigations are very limited due to insufficient analytical methods for these small polymer particles. The fate of such particles remains still unclear, making it necessary to investigate particles below 1 μm in size in toxicological approaches. This talk will give an overview about micro- and nanoplastics research at the BfR, the state of knowledge and the approaches for risk assessment.

Buying conventional foods or going organic? - A comparative study on the perceptions and consumption of organic foods in Germany and Korea -

Holger Preut 한독사회과학회 2017 한독사회과학논총 Vol.27 No.1

유기농업법과 유기농 식품 사용이 토양 및 생태계 시스템 그리고 인간에게 유익하다고 점차 인식됨에 따라, 세계 유기농 식품 시장 역시 괄목할 만큼 발전하였다. 본 연구에서는 한국과 독일의 유기농 운동의 기원을 고찰하면서, 양국의 유기농 식품에 대한 인식 및 소비관련 현황을 살펴보았다. 한국과 독일 양국의 유기농업 현황과 유기농 식품 시장 마케팅의 역사적 행보 및 유기농 식품의 시장수요가 현격하게 차이가 나는 것을 주목하였으며, 이에 근거하여 유기농 식품시장이 독일에서는 주류(主流)시장으로 편입되었으나, 한국에서는 유기농 식품시장이 본질적으로 여전히 틈새시장에 머물러 있다는 결론을 내렸다. 독일에서는 유기농 산업이 진화·발전되어 왔으며, 유기농 식품에 대한 인식 및 소비가 왕성한 것으로 확인되었다. 대부분의 독일 유기농 소비자는 평균 이상의 수입과 교육을 받은 사람들로 인간, 환경 및 동물에 대한 윤리적 가치에 의해 선택의 영향을 받으며, 많은 수의 소비자들 역시 전체론(全體論)적이고 건강한 생활 방식, 유행 및 편의성에 의해 유기농 식품을 선택하는 것으로 확인되었다. 한국의 경우, 소규모로 -특히 어린 자녀가 있는 가정주부, 장년 및 고소득 계층이 중심이 되어- 그리고 대부분 건강상의 이유로 유기농 식품을 구입하는 것으로 조사되었다. 그러나 마케팅 및 인증제도에의 결함, 유기농 식품의 구별성, 유기농 식품의 품질에 대한 신뢰결핍으로 인해 유기농 식품의 인지도 및 유기농 식품의 지속적 구매성은 제한적인 것으로 파악되었다. 한국에서 유기농 식품이 보다 많은 이들에게 확대되기 위해서는 가격대비 효율성 및 유기농 식품의 제품 투명성과 신뢰성, 소비자 행동에 대한 이해를 높이기 위한 노력이 필요하다고 분석된다. The global organic food market has expanded substantially as growing and going organic has widely been perceived as being good for soils, ecosystems and people. Also considering the history of the organic movements, this study investigates the contemporary perceptions and consumption of organic foods in Germany and South Korea. This study concludes that given the historically different commitments to organic farming and marketing, organic foods in Germany have gone main-stream whilst in South Korea organic foods are essentially still much of a niche market. In Germany an organic industry has evolved and organic food awareness and consumption are strong.Most consumers are above average income and education, and driven by ethical values for people, environment and animals. Many consumers also go organic because of a holistic healthy life style, trends and convenience. South Koreans, on a smaller scale - in particular mothers of young children, elders and high income groups – also purchase organic food mostly for health reasons. Here knowledge about organic food and intentions to go organic appear limited due to deficiencies in marketing and labelling, resulting in a lack of product distinction and trust in the quality of organic foods. To popularize organic foods in South Korea, greater efforts should be made to improve cost effectiveness, product transparency and reliability of organic foods, and understanding of consumer behaviour.

Olympic Legacy: Status of Research

Holger Preuss,홍석표 글로벌지식마케팅경영학회 2021 Journal of Global Sport Management Vol.6 No.3

There is no doubt that the topic of legacy of sport events is becoming one of the critical issues in professional sports worldwide. Taxpayers’ money is used to support the staging of events and therefore citizens want a benefit in return. Many legacies though are intangible and therefore not easy to measure. As economic profits are difficult to obtain, ecological footprints are given due to needed travelling and social benefits are not easy to measure. Overall, the Olympic Games do not visibly and obviously change the host city towards sustainability and long-lasting positive developments. The articles reveal the breadth of topics that are located within the scope of legacy. The research areas touch on legacies that are under-researched and for which there is scant legacy information in the literature, i.e., the legacy of Olympic Winter Games, Youth Olympic Winter Games, unsuccessful Olympic bid cities and non-host Olympic cities.

Why still so few children? An analysis of the impact of recent family policies on low fertility in Germany and South Korea

Holger Preut 한독사회과학회 2016 한독사회과학논총 Vol.26 No.3

독일과 한국의 출산율은 수십 년 동안 낮은 수치를 기록하고 있다. 최근 출산율은 주로 아동보육에 대한 보수적인 사회태도, 노동시장 상황과 가족 정책 의 결과물로 여겨진다. 독일과 한국의 가족 비우호적인 고용주들과 불안한 노동시장은 젊은 사람들이 출산을 미루거나 포기하도록 강요하는 요인이 된다. 놀랍게도, 출산율 위기를 해결하기 위한 양국 정부의 강한 의지가 반영된 정책은 21세기 초에 이르러서야 비로소 확인되는데, 그 이후 시행된 독일과 한국의 가족정책은 직업과 보육을 양립하는 여성들에게는 그 효과가 제한적이었다. 통일 이후 독일의 가족 정책은 보육 시설의 대규모 증대, 새로운 유급 육아휴직 혜택을 통해 그 위기 상황에 대응하고 있다. 그러나 '남성 생계부양, 여성 가사육아' 라는 이전 서독의 전통적인 역할 프레임과 자녀 양육 의무를 어머니에게 일임하는 사회적 관습은 여전히 출산율의 증가를 저해하는 족쇄가 되고 있다. 한국은 출산 휴가, 육아 휴직, 그리고 근로시간 단축 등의 제도적 개선을 시행하고 있으며, 자녀 교육비용과 주택의 비용을 절감하기 위한 정책들도 진척 중에 있다. 그럼에도 이러한 정책들은 모두 직장 문화와 성역할 개선 노력에 의해 보완되어져야 한다고 본다. Fertility rates in Germany and South Korea have been low for decades. Recent trends in fertility rates are largely a result of the labour market, family policy and social attitudes towards child-care. In both countries unstable employment conditions and family-unfriendly employers continue to push young people to delay and abandon childbearing. Both governments’ full commitment to tackle the fertility crisis only arose in the early 21st century and ever since their family policies have had limited impact on the tension faced by women between child-care and workforce participation. Unified Germany’s modernized family policy has addressed the crisis through massive expansion of child-care facilities and the new income-related parental leave benefits. However, the legacy of former West Germany’s male breadwinner-female care-giver framework and social attitudes stressing mother child-rearing obligation still hamper increases in fertility rates. South Korea’s family policies’ institutional changes – maternity leave, child care leave, and a reduced work schedule – including efforts to reduce the cost of children’s education and housing have been advances. Nonetheless, these policies need to be complemented by efforts to change the work culture and gendered society.

Development of an Automation Library for the Mechatronics Development System EasyKit and a Typical Test Application

Holger Bonicke,Christoph Ament 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

Today, the importance of developing reliable mechatronical systems in a cost- and time-efficient way is increasing. EasyKit, which is presented in this paper in a short form, is a system which was developed to assist in this process. It reduces the time and money efforts of the development of mechatronical systems. EasyKit is delivered with a graphical software development environment, which is called EasyLab. This software can be used to program microcontrollers in a simple way. When EasyKit was developed, only basic generic libraries for graphical software development were included, which made the development of complex programs inefficient. To solve this problem, a basic library for automation purposes was developed and is presented in this paper. The components and their easy usage are shown. The EasyKit system and its development environment were used for a variety of test applications. One of them, an air control test application, which will be used for calibrating sensors of air passages, is presented in this paper.