Search

Field-based analysis is more desirable than laboratory-based analysis in that it allows continuous monitoring and maintains sample integrity. In this study, we focus on plasma digestion and ion-selective electrode technologies for rapid on-site quantitative measurement of phosphorus in natural waters.

The concept of entrepreneurship has been recognized and developed in the various context such as commercial entrepreneurship, corporate entrepreneurship, social entrepreneurship, and academic entrepreneurship. Many research-centered universities have been sources of spin-off companies and technology commercialization. Now they are transforming into entrepreneurial universities. The purposes of this paper are (1) to develop the model of entrepreneurial university, (2) to analyze activities of some entrepreneurial universities, (3) to design a system to promote technology commercialization and entrepreneurship education, and (4) to suggest further research agenda for academic entrepreneurship. KAIST has been a leading research-centered university in Korea and has played a key role in promoting R&D commercialization and university spin-off. To cope with social demands on new roles of universities, KAIST is accelerating the innovation on education, research and commercialization system. This paper reviews the activities, strategies and performance of technology commercialization and university spin-off, and presents a new model of entrepreneurial university. Many leading universities have their own strategies and systems, and are facing many challenges. This paper will discuss the challenges ahead and suggest research agenda for university entrepreneurship. This study could provide a ground for discussion on specific issues related to academic entrepreneurship.

In recent years, the research area of material processes using atmospheric pressure plasma jets (APPJs) has rapidly grown. However, APPJs are based on weakly ionized discharge, and the plasma intensity produced by APP J s is relatively low and not suitable for uniform treatment compared with those of low-pressure discharge. In order to overcome these problems, multi-tube array-based APPJs devices have gained attentions on intense and stable plasma for uniform treatment. We have recently reported a realizing intense plasma cloud using novel APPJs device with guide-tube and bluff-body1.

Owing to their promising applications in gas sensors devices, organic conjugated polymers (conducting polymers) have been continuously studied during the past few decades1. We have recently reported a new polymer synthesis method by using novel atmospheric pressure plasma (APP) jets (APPIs). The nitrogen-containing polymer nanoparticles are successfully synthesized by using aniline and pyrrole monomers via a simple APP polymerization technique2, However, the interactions between the use of the novel APP polymerization technique and the sulfur-containing conjugated polymer (polythiophene) are not well known. Accordingly, in this study, polythiophene films are directly deposited on substrates with interdigitated electrodes by APPJs and their gas sensing properties are investigated. This plasma polymerization technique can be used to synthesize the poly- and single-crystalline high-density thin films with nanoparticles by enhancing the sufficient nucleation and recombination. The nanostructured conductive porous polythiophene sensors prepared by novel APPJs polymerization technique showed the excellent NO 2 -sensing properties at room-temperature. The detailed APP polymerization system, sensor property, FT-IR, FE-SEM image, XPS, TOF-SIMS, resistance, and related mechanism are studied and will be discussed in detail. This research contributes to the design of highly sensitive NO 2 gas sensors adopting the novel plasma-polymerized conductive porous polymer as sensing materials.

Recently researches on water-pretreatment process by the decomposition of harmful organic materials using atmospheric pressure plasma (APP) have gained attentions due to the increase in the interests of water pollution1. Generally, organic materials are decomposed by active species, such as hydroxyl $\left(\text{OH}^{*}\right), \mathrm{O}^{*}, \mathrm{H}^{*}, \mathrm{H}_{2} \mathrm{O}_{2}, \text{HO}_{2}$ and ozone $(\mathrm{O}_{3})$ radicals generated in sample water using conventional large size APP methods. However, these methods require lots of spaces and high cost for operating equipment because of high power-consumption and relatively big size of equipment. Furthermore, there has been no report on the compact, portable, and low power-consumption APP device for direct water-pretreatment sensors applications. Therefore, it is necessary to develop the microplasma water-pretreatment device with streamer discharge, which is compact, portable, and low power-consumption, in order to increase the efficiency of plasma generation for direct water-pretreatment. So, here we report the novel and portable APP device for rapid water-pretreatment with low-power consumption by microplasma discharge. Thereby, optical emission spectroscopy (OES), Fourier transforms infrared spectroscopy (FT-IR), UV-visible spectroscopy (UV-vis.), and PH meter measurements have been investigated systematically with respect to various parameters, such as multi-pin to plate, DBD-to-water structures, micro-pulse, nano-pulse, electrode shape, and driving condition, respectively. The detailed characterization of water-pretreatment by atmospheric pressure microplasma with nano-pulse conditions using OES, FT-IR, UV-vis, and PH meter are under study and will be discussed in detail.

Nanogenerator (NG) based on the piezoelectric, which can convert mechanical energy to electric power, can be an interesting candidate for energy harvesting applications. These fabricated nanogenerators with nanomaterials have attracted lots of attentions since the first report on utilizing piezoelectric zinc oxide nanowires for mechanical energy harvesting1. More and more piezoelectric nanomaterials have been researched in mechanical NG device such as ZnO, PZT, and BaTiO 3 . Compared with those inorganic nanomaterials in realistic applications, piezoelectric polymers are promising alternatives for flexible NG devices. Especially, polyvinylidene fluoride (PVDF) has a relatively high piezoelectric property owing to its polar crystalline structure, consisting of at least four different crystalline forms (namely $\alpha, \beta, \gamma,$ , and $\delta),$ among which $\beta$ phase is primary for its piezoelectric activity2, In this study, in order to characterize the crystal structure and morphology of deposited PVDF polymer film by using novel atmospheric pressure plasma jets (APPJs) polymerization system, secondary electron microscopy (SEM), Fourier transforms-infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) have been investigated systematically for the energy-harvesting element of a flexible piezoelectric nanogenerator. From these results, SEM results show that PVDF nanoparticles are clearly observed and the thickness of PVDF polymer film is about 2 $\mu \mathrm{m}$ on flexible substrate by using novel APPJs at room temperature with PVDF/ DMF solution. The detailed characterization of PVDF polymer films using SEM, FT-IR, and XRD are under study and will be discussed in detail.

This paper presents a 300 W GaN power amplifier operating in the LTE band 7 (2.62∼2.69 GHz). From the loadpull simulation, optimum impedances of the GaN HEMT at the fundamental frequency and the second harmonic frequency are extracted for a maximum output power. The matching circuits that give the nearly optimum second harmonic impedances are implemented on a titanate substrate with a high dielectric constant and are integrated with a bare GaN transistor in a ceramic package. The fabricated power amplifier shows a saturated output power of 258∼324 W and a drain efficiency of 67∼73 % under the pulsed condition of 1 msec period and 10 % duty cycle. It also has an output power of 80∼85 W and a drain efficiency of 42∼49 % at ACLR of 30 dBc with the LTE input signal.

This paper proposes an omni-directional power-assist-modular(PAM) mobile robot for total nursing service system. We focus on verifying a kinematic model of dual-offset active wheel casters for PAM. To control holonomic mobile robotics system, we approached the kinematic model in the aspect of coordinate transformation, and obtained driving velocity and steering velocity from the Cartesian coordinate. Based on the kinematic model, we designed dual-offset active wheel casters with a differential gear mechanism and applied them into PAM. As a result, PAM can move easily at a confined area such as a patient's room of the hospital.

Recently, nanosatellites (nanosats) electric propulsion systems have attracted attention to researchers due to very simple structure and low delivery cost1. However, present electric propulsion system, such as hall effect thruster, arcjets, and plasma thrusters, have low thrust, short lifetime, no flexibility2. Among various thruster systems, the plasma thruster has versatile advantages such as high specific impulse and small size for future nanosats. However, it is difficult to generate high thrust because the plasma, which is produced by conventional devices, has low energy. In addition, these conventional plasma thrusters also are difficult to change direction because these thrusters have limited flexibility. New solutions must be offered to space mission designers to overcome these limitations. Here, we have proposed the highly energetic intense coupled microplasma with a single bundle of three hollow-core optical fibers to obtain both the high thrust and flexibility. The proposed flexible microplasma thruster, which has a protruded optical-fiber, can generate the highly energetic intense coupled microplasma with a strong plasma emission and a high thrust. The detailed novel microplasma device, microplasma physics, discharge and thrust characteristics, currents, fluid simulation, high-speed intensified chargecoupled device (ICCD) images, and more detailed mechanism are studied and will be discussed in detail. This research contributes to better understanding on the novel structure and design of future microplasma thruster system by analyzing microplasma phenomena.

A performance of circuit breaker is dependent on the dynamic behavior of spring operating mechanism (SOM) in terms of mechanical system. The response speed of the circuit breaker is one of important part in the performance of circuit breaker and the response speed of the circuit breaker was determined by latch mechanism. The latch mechanism consists of solenoid actuator and several linkages with joints and springs. In this paper, the design variables were selected by using sensitivity analysis and design of experiment (DOE). The optimum design was executed and the response time was reduced. To validate the optimum value, the simulation results were compared the experimental results which were measured using a high speed camera. The simulation and experimental results were similar in reduced time.

A circuit breaker is widely used to protect electric power system from fault of electric currents or system errors. In this study, a circuit breaker with spring operating mechanism operated by the stored elastic energy of the close spring was addressed. In case of the closing mechanism of this circuit breaker, the torque generated by closing spring rotates the closing shaft. A cam which is located on the closing shaft axis rotates the opening shaft. Several linkages are moved by cam-follower mechanism. In this case, rotating cam is important component for transferring energy generated by closing spring energy. In this paper, multibody dynamic model of a circuit breaker including switch mechanism and cam-follower mechanism was developed using ADMAS. To validate the developed model, the closing velocity of simulation and experiment results was compared. With the developed multibody dynamic model, cam profile optimization was conducted. Cam profile was constructed by spline function including design points. Each point was calculated by radius according to regular interval angle in polar coordinate. Design sensitivity analysis and optimization of cam profile was conducted for decreasing the closing velocity after contacting interrupt.

A performance of a high-voltage circuit breaker is mainly dependent on the mechanical efficiency of spring operating mechanism. To predict the performance of the circuit breaker, the analysis of the performance of the circuit breaker is required. In this paper, the analysis model including friction and efficiency of spring was developed to predict a dynamic behavior of circuit breaker. The analysis model was developed by using 1-D based multi-physics tool, the friction and efficiency of spring were measured by using an electric linear actuator, a hydrostatic actuator and a high speed camera. The friction and efficiency of spring were acquired in experiment, the acquired data were applied in analysis model. The simulation results were compared to experimental results in dynamic behavior of circuit breaker. Hence, it is possible to predict the dynamic characteristics of the circuit breaker.

Since the performance of a circuit breaker which has the spring operating mechanism mainly depends on the dynamic behavior of a coil spring, the analysis of the dynamic behavior of a coil spring is required for a performance evaluation of a circuit breaker. When a spring moves so fast from the releasing state, a lot of energy is used to move a self-weight of a spring. In this study, a release test bed is designed for evaluating the dynamic behaviors of a coil spring. From the release tests, the dynamic behaviors of a coil spring are analyzed. RecurDyn is employed to carry out the computer simulation and results are compared with test results. The actual energy transferred to the follower during high-speed motion is analyzed through the comparisons of the kinetic energy between the experiment and the computer simulation.

Intermetallic compound (IMC) formation in Cu wire bond is of great technological importance since it underpins the bonding characteristics between Cu wire ball and Al pad, which are directly associated with long-term reliability. Thus, extensive works have recently been performed to understand IMC formation at the interface between Cu wire ball and Al pad metallization. Most of the previous works implemented qualitative scanning electron microscopy (SEM)-based analysis techniques such as energy dispersive x-ray spectroscopy (EDS) and electron probe micro-analyzer (EPMA) to identify IMC phases. However, to understand IMC growth and phase evolution in depth, transmission electron microscopy (TEM)/nano-beam electron diffraction (NBED) study is necessary. We have recently performed TEM/NBED investigation on 20 μm (=0.8 mil) Cu wire bond interface and unambiguously verified the presence of metastable θ'-CuAl 2 IMC phase as the majority IMC phase. In this study, further comprehensive IMC phase analyses were performed for side-by-side comparative study between 18 μm (=0.7 mil) Pd-coated Cu wire and 18 μm Pd-coated Cu wire that was followed by Au flash coating using SEM and TEM/NBED in conjunction with structure factor (SF) calculation. For SEM examination, cross-section of Cu wirebond samples was prepared by a combination of mechanical polishing and Ar ion cross-section polisher. TEM sample was prepared using dual-beam focused ion beam technique. Cross-sectional SEM result shows that in both of the wirebonds, discontinuous IMC patches were formed at the Cu/Al interface immediately after packaging, and they grow toward Al pad after HTS test at 150 °C for 1000 h. TEM/NBED result combined with SF calculation revealed that in both of the wirebonds, the majority of IMC phase was metastable 9'-CuAl 2 phase while Cu 9 Al 4 phase was also found occasionally between metastable 9'-CuAl 2 phase and Cu wire in as-packaged wirebonds. After HTS test, both of the phases grow in size. SEM, and TEM/NBED results suggest that there is no Au coating effects in terms of IMC morphology, phase formation and their thermal evolution. Based on NBED and EDS results, possible Cu 9 Al 4 growth mechanism will be discussed.

A wearable robot is the robotic system capable of augmenting or amplifying the wearer's muscle strength. To imitate human arms, the recognition of muscle stiffness and the reflection of the motion are very important. In this paper, the upper limb of the wearer is bandaged with the pneumatic muscle stiffness sensor (MSS), and the wearer's intention is estimated by recognizing the movement of the muscle. In addition, a variable stiffness actuator (VSA) is used to imitate the predicted motion of the wearer and simultaneously to unburden the weight by increasing its stiffness. It is shown that the proposed system is capable of distinguishing between the wearer's intention and the external load.

Due to the importance of fundamental bonding mechanism associated with intermetallic compound (IMC) formation in Cu wire bond, extensive studies have recently been made to understand IMC formation at the interface between Cu wire ball and Al pad metallization. Most of the previous works implemented qualitative scanning electron microscopy (SEM)-based analysis techniques such as energy dispersive x-ray spectroscopy (EDS) and electron probe micro-analyzer to identify IMC phases. To understand IMC growth and phase evolution in depth the present investigation systematically uses transmission electron microscopy (TEM)/electron diffraction (ED), EDS and structure factor (SF) simulation for a comprehensive study. A IMC phase analysis was performed for Cu wire bonds using SEM and TEM/nano-beam ED (NBED) combined with SF simulation. For SEM examination, cross-section of Cu wire bond samples was prepared by a combination of mechanical and Ar ion polishing techniques. TEM samples were prepared using dual-beam focused ion beam technique. SEM result showed that discrete IMC patches were initially formed at the Cu/Al interface and they spread across the Cu/Al interface during high temperature storage (HTS) environment at 150 °C for 1000 hours. At the same time the IMC thickens growing towards the Al pad. TEM, NBED, and EDS results combined with SF calculation revealed the evidence of metastable θ ′-CuAl 2 IMC phase formation at Cu/Al interfaces before the HTS test. This θ ′-CuAl 2 IMC phase grew in size after HTS test. Possible reasons for the presence of the metastable CuAl 2 phase are discussed.

Entrepreneurial journey of new business creation starts when a business opportunity is discovered by nascent entrepreneurs. There are many obstacles along the journey, and must be an 'internal driving force' to create entrepreneurial actions for problem solving. This paper develops a new concept of 'entrepreneurial intent' as an internal driving force of opportunity realization with 'drive' (sense of crisis) and 'directivity' (sense of opportunity). Furthermore, it presents a theory of the underlying entrepreneurial process with entrepreneurial intent. Case study methods and grounded theory building are utilized. The results based on cases from high-tech venture firms in Korea show that entrepreneurial intent toward a new opportunity is emerged to collective actions for combining new resources to create new values. The entrepreneurial intent is the extreme level of achievement motivation which is comprised of arousal, direction, and duration (reducing the cognition gap), and drives 3C effects such as 'channeling', 'concentrating' and 'continuing' of entrepreneurial actions. The entrepreneurial actions, in turn, make more chances of serendipity in the external process of networking and gaining resources (reducing the resource gap), and the internal process of value creation. Value creation finally converts discovered opportunities into realized opportunities to complete the entrepreneurial journey.

There are many online communities in Korea. An online community is a group of people that primarily interact via the Internet rather than face-to-face. Many firms are using online communities for communicating with users. The research question we attempt to answer is how online communities can be utilized throughout the NPD process, especially by using an early adopter feedback system. We investigate three leading MP3 player manufacturers in Korea. The number of people in these communities is over 100,000. They use various methods of promoting communication with users. This community can help retrieve valuable insight on customer needs, effective characteristics for new products, and trends for future development. These communities can also provide an effective method of communicating with early adopters. Using an online community is the most effective and efficient way of hearing customers' voices, thereby elucidating the strong and weak points of new products. In addition, communication activities could instill brand loyalty between firm and customers. Making an online community more active is the main challenge of firms that intend to use one. High-quality products, an effective strategy for attracting early adopters, and top management support for online communities are factors that determine the success of growing online communities. We also suggest a theoretical framework for online community development and an early-adopter feedback facilitation process.

In this paper, a fuzzy group method data handling- type (GMDH) neural networks and their application to the container terminal demand forecasting of port transportation system are described. At present, GMDH family of modeling algorithms discovers the structure of empirical models and it gives only the way to get the most accurate identification and demand forecasts in case of noised and short input sampling. In distinction to neural networks, the results are explicit mathematical models, obtained in a relative short time. In this paper, an adaptive learning network is proposed as a kind of neural-fuzzy GMDH. The proposed method can be reinterpreted as a multi-stage fuzzy decision rule which is called as the neural-fuzzy GMDH. The GMDH-type neural networks have several advantages compared with conventional multi-layered GMDH models. The related computer program is developed and successful applications are shown in the field of estimating problem of container terminal demand with the number of factors considered.

In this paper, we propose new dereverberation method for underwater speech communication. The speech signal generated by a fixed one source. Then the signal received on 9 horizontal sensor array in shallow water environment. Finally, received signals are processed dereverberation. The received signals achieved delay-and-sum beamforming and then, signals calculates time delay both each signals. Next, we calculate Hilbert envelope using time delay information and LP residuals. At last, we acquire new LP residuals using various parameters. Proposed technique shows better performance than previous dereverberation technique.

Web services are key applications in business-to-business, business-to-customer, and enterprise applications integration solutions. As the mobile Internet becomes one of the main methods for information delivery, mobile Web Services are regarded as a critical aspect of e-business architecture. In this paper, we proposed a mobile Web Services middleware that converts conventional Internet services into mobile Web services. We implemented a WSDL (Web Service Description Language) builder that converts HTML/XML into WSDL and a SAOP (Simple Object Access Protocol) message processor. The former minimizes the overhead cost of rebuilding mobile Web Services and enables seamless services between wired and wireless Internet services. The latter enhances SOAP processing performance by eliminating the Servlet container (Tomcat), a required component of typical Web services implementation. Our system can completely support standard Web Services protocol, minimizing communication overhead, message processing time, and server overload. Finally we compare our empirical results with those of typical Web Services.