A Highly Reliable Two-Axis MEMS Relay Demonstrating a Novel Contact Refresh Method

Yong-Ha Song,Seung-Deok Ko,Jun-Bo Yoon IEEE 2015 Journal of microelectromechanical systems Vol.24 No.5

<P>This paper reports on a two-axis actuated microelectromechanical systems (MEMS) relay to realize a unique contact-refresh concept. In comparison with all other conventional MEMS relays utilizing only several designated contact spots during their whole lifetime, the proposed concept can change the real contact spots (asperities) by altering the lateral position of contact asperities, thus providing highly reliable contact endurance. In addition, it can enhance lifetime of the switches that fail by contact resistance increase, and potentially even for switches that fail by contact stiction if the contact position is changed before a critical number of switching cycles is reached; however, the device inevitably has a relatively large device area and additional control circuitry in this stage of development. The fabricated relays showed vertical actuation voltages under 40 V, a switching delay of 190 μs, and a maximum lateral displacement of 10 μm. Owing to the suggested contact-refresh scheme, the total contact endurance in one switching device was dramatically increased, and the sum of dozens of lifetimes measured at the selected lateral positions reached 6 × 10<SUP>7</SUP> cycles at 100 mA in hot switching conditions (Au-to-Au contact), which is nearly 50 times higher than the average value of the measured lifetimes in a designated contact spot.</P>

스퍼기어의 접촉응력 해석

이진환(Jin-Hwan Lee),이동형(Dong-Hyong Lee),이권희(Kwon-Hee Lee) 한국기계가공학회 2010 한국기계가공학회지 Vol.9 No.4

This paper presents the study on the contact stress analysis of a pair of mating spur gears during rotation. Contact stress analysis is performed between two spur gear teeth at different contact positions during rotation. An example is presented to investigate the variation of contact stress on a pair of mating gears with contact positions. The variation of contact stress during rotation is compared with the contact stress at lowest point of single tooth contact(LPSTC) and AGMA Equation for contact stress. The results show that contact stress varies along the contact position and gets maximum values in the beginning and end of the contact. In this study, the gear design considering the contact stress on a pair of mating gears is more severe than that of AGMA standard.

The Effect of Contact Frequency with Customers on Relationship Satisfaction

Lia Jung,Seolwoo PARK 사람과세계경영학회 2020 Global Business and Finance Review Vol.25 No.3

Purpose: This study is to examine the moderating role of contact mode and customer attachment style on the effects of contact frequency on relationship satisfaction. Design/methodology/approach: To explain this phenomenon, literature reviews about contact frequency, contact mode, relationship satisfaction, the moderating effect of contact mode (personal vs.impersonal), and attachment style (anxious vs.avoidant).SEM (Structure Equation Model) was suggest to check these relationships using PLS. Findings: Bootstrapping analysis was performed using process macros to find the relationship between contact frequency and relationship satisfaction.As a results, Contact frequency does not significantly affect satisfaction with a company; however, this independent variable affects satisfaction with a company via satisfaction with the service provider.Anxious people are known to be dependent, while avoidant people are independent, so customers’ attachment styles influence their relationship satisfaction.Personal contact modes, such as by telephone, are found to be more positive than impersonal contact modes, such as group email, for relationship satisfaction.The results of this study show that customers prefer personal contact to impersonal contact.Moreover, for both anxious and avoidant customers, frequent contact has positive effects on customer satisfaction with service providers and organizations. Research limitations/implications: This study provide two contributions.First, it confirmed the mediation effect of the customer-service-provider relationship.Customers’ satisfaction with a company depends on their satisfaction with its service providers.Second, this study identified a moderating role played by the contact mode and the customer’s attachment style.In regard to future research, it would be nice to add cases for increasing customer-satisfaction level with service firms and to focus on other industries to expand current research findings. Originality/value: The findings provide customer segmentation criteria and guidelines for effective relationship marketing activities in service field.

소통의 관점에서 본 접촉즉흥에 관한 연구

안신희 한국무용예술학회 2010 무용예술학연구 Vol.30 No.-

Study of Contact Improvisation which solves problems of communication with direct reaction between the body and another body has a very significant meaning in twenty first century where communication is considered as a big issue. Therefore, a purpose of this study is to abstract the common conditions which communicate to a concept of communication and, based on that, to identify communicating components expressed in Contact Improvisation. Process of this study is as follows. In chapter two, communication which contains a relationship is reviewed, and conditions of communication which can have a particular relationship are analyzed. In chapter three, ‘mart body which reacts’which is an important concept in Contact improvisation is looked at. In chapter four, based on the previous conditions of communication, components of communication expressed in Contact Improvisation are identified. As a result, it has been found out that communication does not simply mean understanding one another but provides opportunities to create more values of ourselves. A human joys of being alive when he becomes aware of hisexistence though meeting others rather than though his existence itself. True communication warms relationships between people and lead to change. Contact Improvisation is a dance which continues to develop and speaks for true communication with movement. Components of communication that Contact Improvisation has are as follows. Firstly, Contact Improvisation is only achieved by dancing with someone. If communication is achieved through a relationship, Contact Improvisation starts the relationship by a contact. A contact in Contact Improvisation contains cooperation and recognition of a partner as well as ‘transcendence’to develop myself to make the best harmony with the partner. Secondly, as a relationship can flow smoothly only when my reaction towards the partner’ reaction(demand) is appropriate Contact Improvisation is highly interested in reaction. This reacting is, as a part of communication, not a passive reaction but to make the most out of being with a partner. Wise people in the world says to identify differences from others and to maximize self’ capabilities(conditions) in order to decrease the differences. ‘est reaction’in contact is an opportunity for a self to grow up, and having an opportunity to enhance self’ life to its greatest potentials. Thirdly, a main subject of reacting is the body. Contact dancers define a body as ‘Smartly reacting body’and accept that it can achieve every potentials. Also, they try to get ‘Objective attitude’as a smart body, outstanding reflexes and intuition. This is a condition to obtain true communication and a method that approaches to deeper unconscious level than which masters of contact suggested of. Fourthly, Contact Improvisation stresses a body which is open to make a good contact, “seeing though the body”and “listening though the skin” Contact dancers extend their bodies with nature to create the best movement. They also try to listen intently to the voice of the body coming from their partners with all their senses in order to become one. An extreme harmony from ‘he third power’leads me and you who are transcendent to dance. Sharing a dance together helps creating strong team spirit and friendship. A purpose of communicating is to get better. I believe communicating is a certain space of life which gives a precious gift that I can get better when we strive ourselves to get better. It is hoped that this study is used as a basic resource for other studies on communicating or Contact Improvisation.

Social Contact Patterns Associated With Tuberculosis: A Case-control Study in Southwest Iran

Neda Amoori,Bahman Cheraghian,Payam Amini,Seyed Mohammad Alavi 대한예방의학회 2022 예방의학회지 Vol.55 No.5

Objectives: Tuberculosis (TB) is a major public health concern worldwide. Social contact patterns can affect the epidemiology and risk of airborne diseases such as TB. This study was designed to investigate the social contact patterns associated with TB. Methods: In this case-control study, groups of participants with and without TB were matched by age and sex. Participants reported the nature, location, frequency, and average duration of social contacts over 1 month. The duration and number of social and spatial contacts were compared between groups using the chi-square test and the t-test. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to quantify the relationship between social contact time and TB status. Data were analyzed using Stata version 11 statistical software. A p-value of <0.05 was considered to indicate statistical significance. Results: In this study, 80 patients with TB and 172 control participants were included, and a total of 3545 social contacts were registered. Social contact with family members (OR, 1.72; 95% CI, 1.10 to 2.40), contact with a person with TB (OR, 1.53; 95% CI, 1.16 to 2.01), and contact at the participant’s home (OR, 1.42; 95% CI, 1.19 to 1.82) were significantly associated with TB status. Conclusions: The duration of long-term social contact, rather than the number of contacts, may be the main contact-related factor associated with TB transmission in this population. The focus of contact-tracing efforts should be on finding and treating both family members and long-term contacts in non-household settings.

원형 핀과 구멍의 접촉에서 헤르츠 응력장 가정을 위한 조건

김형규(Hyung-Kyu Kim) 한국트라이볼로지학회 2015 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.31 No.5

This paper focuses on the conformal contact problem. A typical example of conformal contact is the contact between a pin and hole. In particular, this paper focuses on the condition for assuming a contact stress field to be a Hertzian pressure profile by using well-known classical solutions associated with Hertzian contact. Persson first developed the conformal contact analysis method around half a century ago, but there have been no significant improvements since then. The present research also adopted this method, but developed new solutions from the viewpoint of application to structural design. The analysis began with a comparison between Persson° Øs conformal contact stress and the Hertzian stress fields. The next step was to check the differences in the normalized stress values of both. This study used the tolerance for the difference in the peak stresses of Persson° Øs solution and the Hertz solution to validate the Hertzian assumption. This gave the range for the difference in radii of the pin and hole when the contact force and mechanical properties of the material are specified. The results showed that, at a tolerance of 5%, the Hertzian assumption is valid if half of the contact angle is less than 35°ý. In addition, the Hertzian assumption holds even for a relatively long contact length, in contrast to the general incomplete contact problem. This paper discusses these results along with other aspects of the application to the design.

Effect of Thermal Annealing on Ni/Au Contact to p-GaN

이호성,문진영,김준호,안철현,조형균,이주영,김홍승 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6

We deposited Ni (13 nm) / Au (30 nm) layers on p-GaN by using the dc sputtering method in order to produce low-resistivity Ohmic contacts. The Ni (13 nm) / Au (30 nm) contact layers were annealed in air for 15 min at various temperatures. The electrical and the structural properties of the Ni/Au contact to p-GaN were investigated. The current-voltage measurement showed that the resistance of the as-deposited sample was very high. However, the sample annealed at 600 ℃ showed Ohmic-like behavior with a specific contact resistance of 1.9 × 10−3 cm2. Further increasing the temperature caused the Ohmic-like behavior to be degraded. Transmission electron microscopy and Auger electron spectroscopy were used to characterize the interfacial structure between the Ni/Au electrode and the p-GaN layers. The Ni layer was in contact with the p-GaN before annealing. However, after annealing, the Au layer had diffused from the top layer to the interface. The Au layer on the p-GaN surface resulting from the indiffusion of Au atoms during annealing may contribute to effective Ohmic contact formation. We deposited Ni (13 nm) / Au (30 nm) layers on p-GaN by using the dc sputtering method in order to produce low-resistivity Ohmic contacts. The Ni (13 nm) / Au (30 nm) contact layers were annealed in air for 15 min at various temperatures. The electrical and the structural properties of the Ni/Au contact to p-GaN were investigated. The current-voltage measurement showed that the resistance of the as-deposited sample was very high. However, the sample annealed at 600 ℃ showed Ohmic-like behavior with a specific contact resistance of 1.9 × 10−3 cm2. Further increasing the temperature caused the Ohmic-like behavior to be degraded. Transmission electron microscopy and Auger electron spectroscopy were used to characterize the interfacial structure between the Ni/Au electrode and the p-GaN layers. The Ni layer was in contact with the p-GaN before annealing. However, after annealing, the Au layer had diffused from the top layer to the interface. The Au layer on the p-GaN surface resulting from the indiffusion of Au atoms during annealing may contribute to effective Ohmic contact formation.

푸드서비스산업에서 고객지향적인 서비스 컨택요소의 탐색적 연구

한명애 ( Myung Ai Han ),정유경 ( Yu Kyeong Chong ) 대한영양사협회 2015 대한영양사협회 학술지 Vol.21 No.1

The purpose of this study was to provide preliminary data for competitive dominance in an institutional foodservice environment. Data were collected from 85 experts and practitioners on customer-oriented service contact elements and contact fields in the foodservice industry. PASW Statistics ver.18 and MS Excel were used for data analysis. From the pilot study, 67 service contact-elements were derived. Contribution rate analysis and frequency analysis in each contact field were performed in order to categorize four factors, including environment-oriented contact, product-oriented contact, service-oriented contact, and image-oriented contact fields. Thirty three contact elements were derived, and environment-oriented contact consisted of eight contact- elements (cleanliness of restaurant/kitchen, etc.), product-oriented contact consisted of twelve contact- elements (food taste, etc.), service-oriented contact consisted of seven contact-elements (service quality, etc.), and image-oriented contact consisted of six contact-elements (image/reputation, etc.). The results of study will be useful to develop an effective marketing program for competitive dominance in an competitive foodservice industry environment.

Effective inter-residue contact definitions for accurate protein fold recognition

Yuan, Chao,Chen, Hao,Kihara, Daisuke BioMed Central 2012 BMC bioinformatics Vol.13 No.-

<P><B>Background</B></P><P>Effective encoding of residue contact information is crucial for protein structure prediction since it has a unique role to capture long-range residue interactions compared to other commonly used scoring terms. The residue contact information can be incorporated in structure prediction in several different ways: It can be incorporated as statistical potentials or it can be also used as constraints in ab initio structure prediction. To seek the most effective definition of residue contacts for template-based protein structure prediction, we evaluated 45 different contact definitions, varying bases of contacts and distance cutoffs, in terms of their ability to identify proteins of the same fold.</P><P><B>Results</B></P><P>We found that overall the residue contact pattern can distinguish protein folds best when contacts are defined for residue pairs whose Cβ atoms are at 7.0 Å or closer to each other. Lower fold recognition accuracy was observed when inaccurate threading alignments were used to identify common residue contacts between protein pairs. In the case of threading, alignment accuracy strongly influences the fraction of common contacts identified among proteins of the same fold, which eventually affects the fold recognition accuracy. The largest deterioration of the fold recognition was observed for β-class proteins when the threading methods were used because the average alignment accuracy was worst for this fold class. When results of fold recognition were examined for individual proteins, we found that the effective contact definition depends on the fold of the proteins. A larger distance cutoff is often advantageous for capturing spatial arrangement of the secondary structures which are not physically in contact. For capturing contacts between neighboring β strands, considering the distance between Cα atoms is better than the Cβ−based distance because the side-chain of interacting residues on β strands sometimes point to opposite directions.</P><P><B>Conclusion</B></P><P>Residue contacts defined by Cβ−Cβ distance of 7.0 Å work best overall among tested to identify proteins of the same fold. We also found that effective contact definitions differ from fold to fold, suggesting that using different residue contact definition specific for each template will lead to improvement of the performance of threading.</P>

Clean Interface Contact Using a ZnO Interlayer for Low-Contact-Resistance MoS₂ Transistors

Jang, Jisu,Kim, Yunseob,Chee, Sang-Soo,Kim, Hanul,Whang, Dongmok,Kim, Gil-Ho,Yun, Sun Jin American Chemical Society 2020 ACS APPLIED MATERIALS & INTERFACES Vol.12 No.4

<P>Two-dimensional transition metal dichalcogenides (TMDCs) have emerged as promising materials for next-generation electronics due to their excellent semiconducting properties. However, high contact resistance at the metal-TMDC interface plagues the realization of high-performance devices. Here, an effective metal-interlayer-semiconductor (MIS) contact is demonstrated, wherein an ultrathin ZnO interlayer is inserted between the metal electrode and MoS<SUB>2</SUB>, providing damage-free and clean interfaces at electrical contacts. Using TEM imaging, we show that the contact interfaces were atomically clean without any apparent damages. Compared to conventional Ti/MoS<SUB>2</SUB> contacts, the MoS<SUB>2</SUB> devices with a Ti/ZnO/MoS<SUB>2</SUB> contact exhibit a very low contact resistance of 0.9 kΩ μm. These improvements are attributed to the following mechanisms: (a) Fermi-level depinning at the metal/MoS<SUB>2</SUB> interface by reducing interface disorder and (b) presence of interface dipole at the metal/ZnO interface, consequently reducing the Schottky barrier and contact resistance. Further, the contact resistivity of a Ti/ZnO/MoS<SUB>2</SUB> contact is insensitive to the variation of ZnO thickness, which facilitates large-scale production. Our work not only elucidates the underlying mechanisms for the operation of the MIS contact but also provides a simple and damage-free strategy for conventional aggressive metal deposition that is potentially useful for the realization of large-scale 2D electronics with low-resistance contacts.</P> [FIG OMISSION]</BR>