Hwan Jin Kim

This paper explores the motivations of firms to form technological alliances by testing the comparative effects of social networks and absorptive capacity on partner selection, governance and alliance performance. Our results show that absorptive capacity has a greater impact on technological alliance partner selection than social networks. Moreover, while absorptive capacity had a significant impact on technological alliance performance neither absorptive capacity nor social networks were found to significantly affect the choice of technological alliance governance structure. From this, we posit the primary motivation for forming technological alliances among Korean high-tech SMEs is to increase firm absorptive capacity.

This paper examines the impact of two main alliance motivation theories, transaction cost economics (TCE) and resource based view (RBV), on alliance processes among Korean manufacturing high-tech ventures. Results show that TCE and RBV are complimentarily explaining the formation of inter-firm alliances. TCE variables are more related with alliance partner characteristics while RBV is more linked with partner capabilities. Both show positive effects on performance. No significant effect is found on determining an alliance governance structure. While selecting appropriate technological alliance partners show positive effects on performance, no significant effect is found between alliance governance structure and performance. Factors of both theories impacting each alliance stage and analytical explanations of such impacts are discussed.

This paper examines governance structures influenced by relational and performance risk in interfirm alliances. Risk perspectives and transaction cost economics (TCE) generate conflicting hypotheses about predicting alliance governance structures. In a highly risky situation, TCE suggests protective governance mechanisms such as equity joint ventures, whereas risk perspectives suggest more flexible mechanisms such as contract-based alliances. Hypotheses are formulated based on risk perspectives; next, they are empirically tested using 3,228 alliance data records generated during the past 5 years for high-tech industries. The results suggest that risk perspectives provide a better rationale than TCE for choosing an alliance governance structure in a high-tech industry. In the conclusion, we discuss critical issues in current debates about predicting alliance governance structures.

Although entrepreneurial orientation (EO) has been shown to play a key role in increasing firm performance (FP), the effects of EO have been extremely oversimplified. The plethora of empirical studies on EO and FP suggest that the EO-FP relationship is linearly positive regardless of the amount of EO investment. The results show that EO increases FP at the bounded level (i.e., an inverted U-shape). We argue that the excessive use of EO and organizational incapability may contribute to the non-linearity of such effects. We also find that highly dynamic environments enhance the EO-FP relationship. We present prescriptive implications to practitioners on the antecedent conditions for EO practices.

Purpose – Entrepreneurial orientation (EO) and dynamic capabilities (DCs) are two important pillars of increasing performance in fast-changing environments. However, little is known about how the effects of EO and DCs on performance are reconciled, integrated and balanced in terms of contingency factors. In this study, the authors examine three contingencies – firm, market and product characteristics – that significantly affect the level of EO and DCs that firms pursue. Design/methodology/approach – Using survey data on 252 Korean manufacturing SMEs, this study analyzes the influence of EO and DCs on performance using hierarchical regression models. Findings – The results show that EO plays a critical role in small and young firms' performance but that DCs are more critical in incumbent firms. Further, both EO and DCs enhance performance in dynamic markets, and EO increases performance under radical product development, while DCs show negative effects. Originality/value – Given the importance of EO and DCs in increasing firm performance, a lack of empirical attempts have been made to reconcile the effects of EO and DCs in a single research setting. This study provides important and unique implications that can bridge the empirical gaps regarding the complementary roles of EO and DCs by exploring three contingency factors – firm, market and product characteristics – with respect to firm performance.

ABSTRACT In multicore processor, managing shared last level cache is important for overall system performance. Cache contention incurred by OS page caches is serious since the page caches are usually large but less likely reused. The non-reusable page caches, however, pollute the last level cache and interfere the performance of co-running memory-intensive applications. In this paper, we propose a new page cache management scheme which is aimed at minimizing cache pollution incurred by the non-reusable page caches. We identify the non-reusable page caches from a priori information of applications that read page caches once and are unlikely to be access them again. The page caches allocated by the applications are isolated from the other memory data by page coloring, a well-known cache partitioning technique. The isolation guarantees no cache pollution incurred by the non-reusable page caches. The evaluation of our prototype in Linux 2.6.39 showed that cache pollution by non-reusable page caches is successfully alleviated while reducing cache misses by up to 76%. The minimized cache pollution leads to the execution time reduction by up to 50% in our tested cases.

To investigate whether tropical cyclones (TCs) are simulated correctly and verify forecast skill for TCs in numerical weather prediction models, it is necessary to derive trajectories of TCs from model output data and compare them with TC best track information. Because TC tracks are not model output variables, they can be diagnosed from basic variables as pressure, wind, and temperature of a model. A method to decide the TC center is to find out the center manually by looking at the weather charts. However, this manual method is not efficient and sometimes impossible to pinpoint the TC center. Furthermore, determining TC center manually from ensemble prediction results becomes increasingly inefficient. Thus an objective analysis of TC center and trajectory becomes an indispensable work. In this study, a TC tracker that has been developed (hereafter YSU TC tracker) for various model output format including netCDF used in WRF, binary data used in MM5, and GRIB used in GFS and ECMWF YOTC, with various projection including Lambert conformal and cylindrical equidistant (lat/lon) grid is applied for the model output to investigate the performance of the tracker. In detecting step, YSU TC tracker used mean sea level pressure, vorticity and geopotential height at 700 and 850hPa. In tracking step, a search area of next forecast time is determined with specified radius around TC center position of the next forecast time, guessed by using thresholds of cyclone movement such as direction, range of angle, and search radius based on TC speed between two consecutive analyses. The YSU TC tracker developed above was applied on the TCs occurred in 2008 in North Western Pacific. As a forecast data, 0.5° by 0.5° resolution NCEP GFS and ECMWF YOTC data on cylindrical equidistant grid were used. To investigate the performance of the YSU TC tracker, the YSU TC tracker was applied to the GFS data and the results are compared with those from the NCEP tracker. Average track positional errors from the best track data were similar for both trackers, implying that the YSU TC tracker performs as well as the NCEP tracker. To investigate the average forecast skill of the NCEP GFS and ECMWF YOTC data, the YSU TC tracker was applied on both data. The average track positional errors for both data were similar at the initial time, but the average track positional error of the NCEP GFS becomes larger than that of ECMWF YOTC data as the forecast time increases. More comprehensive results will be presented in the meeting.

The mean heat flow in Korea estimated in 365 locations (mines, coal fields, groundwater, hot spring wells) is 60 ± 11 mW/m2; mean geothermal gradients is 25.1 °C/km. High heat flow values appear in the southeastern part, the central western part, and the northeastern part of Korea. In the tectonic provinces, heat flow is 66 mW/m2 for Gyeonggi Massif, 65 mW/m2 for Okcheon Fold Belt, 60 mW/m2 for Yeongnam Massif, 72 mW/m2 for Gyeongsang Basin, and 75 mW/m2 for Yeonil Basin. In the aspect of the lithology, heat flow is 71 ± 2 mW/m2 for the sedimentary rock area, 68 ± 2 mW/m2 for the sedimentary/volcanic rock area, 67 ± 1 mW/m2 for the plutonic rock area, and 62 ± 2 mW/m2 for the metamorphic rock area. In the geological time sequence, heat flow is 78 ± 5 mW/m2 for the Cenozoic strata, 68 ± 1 mW/m2 for Mesozoic, 65 ± 3 mW/m2 for the Paleozoic strata, 67 ± 8 mW/m2 for the Proterozoic strata, and 62 ± 2 mW/m2 for the Archean strata. From the relationship between heat flow and Moho depth, we found that the shallow Moho depth area is likely to have higher heat flow values than the area of the thick crust. Heat production was measured by chemical analysis and gamma-ray logs on basement rocks (86 granite and 37 gneiss samples). The mean heat production is 2.15 μW/m3 for granite, and 2.22 μW/m3 for gneiss. The mean heat production is 2.52 μW/m3 for Gyeonggi Massif, 2.16 μW/m3 for Okcheon Fold Belt, 2.35 μW/m3 for Yeongnam Massif, and 2.01 μW/m3 for Gyeongsang Basin. The tectonic provinces with high mean heat flow tend to have low mean heat production. Therefore, heat production is unlikely to have a first-order importance in determining surface heat flow distribution in Korea. The analysis of 12 heat production and heat flow data sets from granite area in Gyeongsang Basin shows a linear relationship between heat production and surface heat flow, which is known as q=qr+AD, where q is surface heat flow, qr is reduced heat flow, A is heat production, and D is characteristic depth. We found q=47.06+12.29A for Gyeongsang Basin.

Although oxide nanowires offer advantages for next-generation transparent display applications, they are also one of the most challenging materials for this purpose. Exposure of semiconducting channel areas of oxide nanowire transistors produces an undesirable increase in the photocurrent, which may result in unstable device operation. In this study, we have developed a Zn(2)SnO(4) nanowire transistor that operates stably regardless of changes in the external illumination. In particular, after exposure to a light source of 2100 lx, the threshold voltage (V(th)) showed a negative shift of less than 0.4 V, and the subthreshold slope (SS) changed by ∼0.1 V/dec. ZnO or SnO(2) nanowire transistors, in contrast, showed 1.5-2.0 V negative shift in V(th) and an SS change of ∼0.3 V/dec under the same conditions. Furthermore, the Zn(2)SnO(4) nanowire transistors returned to their initial state immediately after the light source was turned off, unlike those using the other two nanowires. Thus, Zn(2)SnO(4) nanowires achieve photostability without the application of a black material or additional processing, minimizing the photocurrent effect for display devices.

This paper presents two of our recent developments in the area of III-V ternary and quaternary materials growth technology for high efficiency thermophotovoltaic (TPV) cells. It is well recognized that growth of TPV cell materials from melts or solutions presents the most economical option. We have investigated bulk substrate growth from melt as well as epitaxial growth from liquid phase. In the bulk crystal growth area, we have been concentrating on the growth of 50 mm or larger diameter device quality ternary III-V substrates. In the epitaxial growth arena, we have developed a new thermochemistry for growing ternary and quaternary compounds on binary substrates from quaternary solutions. Some of the recent results pertaining to the bulk growth of GaInSb and epitaxial growth of GaInAs, InAsSb and GaInAsSb on GaAs substrates will be discussed here.

Shortwave and net radiations are one of the key terms of the surface energy budget and is vitally important for climate studies and many applications such as agricultural meteorology and air-sea-ice interaction studies. The accurate monitoring of net radiation is a fundamental process in various meteorological and ecological studies including the estimation of evapotranspiration (ET) that is a critical process for the energy and hydrologic partitioning at the land surface. Many methods have been developed, and recently the Moderate Resolution Imaging Spectroradiometer (MODIS) also offers an opportunity to improve regional monitoring of shortwave radiation. However, MODIS has a difficulty in obtaining data in cloudy-sky conditions. In this study, we developed and tested applicability of MODIS-MM5 Four Dimensional Data Assimilation (FDDA) system for continuous estimation of ET. On a clear-sky condition, MODIS was utilized to calculate ET, while MODIS-MM5 FDDA system provides input variables for calculation of ET on a cloudy-sky condition. We evaluated the performance of MODIS- MM5 FDDA system by using meteorological data from 72 national weather stations. The reliability of ET estimates was tested with ET measured at two flux tower sites in Korea. Our preliminary results indicate that the MODIS- MM5 FDDA successfully provide input meteorological data for ET estimation on cloudy-sky days and hence, continuous ET monitoring is enhanced when compared with using MODIS data only.

The Kanto earthquake is a great interplate earthquake caused by subduction of the Philippine Sea Plate beneath the Japan Island along the Sagami Trough. The 1923 Kanto earthquake (M=7.9) and the 1703 Kanto earthquake (M~8.0) are two of the most devastating earthquake those struck Tokyo Metropolitan area, respectively. These earthquakes brought large (~5 m) tsunami to the coast area and uplifted the Miura peninsula by ~1.4 m. The tide gauge station, moreover, records the subsidence during the interseismic period before and after the 1923 earthquake. Present study clarifies the past Kanto earthquake prior to the 1703 earthquake based on the sedimentary analysis in the Koajiro bay of the southern Miura Peninsula. The continuous samples of inner bay fine sediments were taken by the boring survey using 3-m-long geoslicer. Three layers of coarse sediments, T1, T2, and T3 units from top toward bottom, are observed in the bay sediments at almost all the sites. These units are composed of mixture of materials such as shell fragments, rock clasts and gravel, and some of units have eroded the lower fine sediments, indicating the event deposits by the strong traction flow. The grain sizes of the bay sediments are grading upward and abruptly become larger after the deposition of the T1, T2 and T3 units. Very little diatom is observed in these units, but the total number of diatoms increase in the bay sediments. The ratio of the marine planktonic species against the benthic species gradually rises from the lower part to the upper part in the bay sediment. In the tidal flat sediment, the freshwater planktonic species appear in place of the marine planktonic diatom. The changes of grain size and diatom species make a presumption that the sea depth suddenly becomes shallow by the event and deeper during the interseismic period. The T1, T2 and T3 units, thus, are correlated with the tsunami deposits conveyed by the Kanto earthquake. The T1 and T2 units are inferred to be the tsunami deposit of the 1923, and 1703 earthquakes, respectively, from Pb-210, Cs-137, and C-14 dating. The C-14 age of 1058-1262 AD (2 sigma) is taken from the bay sediments immediately below the T3 unit. Above the T3 unit, the ages such as 1300-1430 AD and 1460-1650 AD are obtained. The T3 unit is most likely to be the tsunami deposit of the 1293 earthquake candidate from historical documents.

Résumé/Abstract The role of the grain boundary on the room temperature resistivity of Pb (Fe 1/2 Nb 1/2) O 3 (PFN) was investigated using parameters such as temperature dependence of resistivity, complex impedance spectroscopy and X-rayphotoelectron ...

This study dealt with the preparation and characterization of coumarin-6 loaded poly(caprolactone) grafted dextran (PGD) nanoparticles (NPs) and evaluation of cellular uptake by using human gastric cancer cell line (SNU-638), in vitro. The potential application of these PGD NPs for sustained drug delivery was evaluated by the quantification and localization of the cellular uptake of fluorescent PGD NPs. Coumarin-6 loaded PGD NPs were prepared by a modified oil/water emulsion technique and characterized by various physico-chemical methods such as, laser light scattering for particle size and size distribution, atomic force microscopy (AFM), zeta-potential and spectrofluorometry to identify the release of fluorescent molecules from the NPs. SNU-638 was used to measure the cellular uptake of fluorescent PGD NPs. Confocal laser scanning microscopic images clearly showed the internalization of NPs by the SNU-638 cells. Cell viability was assessed by treating the SNU-638 cells with PGD NPs for 48 h. The results reveal, that these biodegradable polymeric NPs holds promise in biomedical field as a carrier.

There are two well established pumped schemes of X-ray lasers used in applications. The differences in the plasma kinetics and output of an X-ray laser pumped by a single profiled and double pump laser pulses in the grazing incidence pumping geometry are analysed. The differences caused by the structural features of the irradiating pulses were observed in both the experiment and numerical modelling. It was found that the structure of the profiled pulse is not the optimum one. The possible ways of the performance improvement are analysed by numerical modelling.

We apply a three-dimensional (3D) edge finite-element method (FEM) code developed for computing magnetotelluric (MT) responses to a model having arbitrarily complex topography and subsurface structure. Edge FEM uses a vector shape function at each edge of hexahedral element, satisfying the continuity of the tangential electric field even at conductivity boundaries. The modeling algorithm has been successfully verified for COMMEMI 3D-2 and 2D ridge models. Using a trapezoidal hill model, we investigate a 3D topographic effect on MT responses to know whether it can be reduced by a correction procedure. This correction technique assumes that the topographically distorted subsurface response is equal to the undistorted subsurface response multiplied by a distortion tensor. This tensor is a function of frequency and receiver position, and is calculated by normalizing the impedance for a topographic model having a homogeneous medium with the half-space impedance. The 3D terrain correction procedure reduces distortions caused by the topographic effect and improves the quality of subsurface interpretation. Numerical experiments indicate that although significant MT anomalies can be generated by topographic features, the correction procedure reduces distortions by the topographic effect and improves the quality of subsurface interpretation. Topography-corrected data show more clearly the response of subsurface conductivity structure, making quantitative interpretation more valid.

Forward osmosis (FO) is a membrane-based desalination technique using an osmotic pressure gradient as a driving force. FO enables lower energy consumption to produce water than reverse osmosis (RO) because it does not require high transmembrane pressure. However, FO ...