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We perform an event study on 2824 cases of domestic mergers and acquisitions (M&A) that were disclosed in the Korean domestic stock exchange and took effect between 2002 and 2015. We focus on Korean capital markets to define the factor variables affecting the disclosure effect of M&A in high-tech industries and the effect of disclosure on long-term performance. We find the following. First, the disclosure effect of M&A benefits acquirers’ shareholder wealth; this effect is more pronounced for high-tech firms than for non-high-tech firms. Second, M&A of high- and non-high-tech firms harm acquirers’ shareholder wealth via the disclosure effect. Finally, M&A between high- and non-high-tech firms negatively affect long-term firm performance. However, acquirers that are mature high-tech firms have a positive effect on long-term performance. This result affirms that organizationally mature firms adapt better to highly specialized technologies and knowledge that are not yet internalized as corporate routines owing to their learned capabilities and breadth of experience. This study provides a significant novel perspective on high-tech M&A by emphasizing the financial performance of firms involved in them.

For future exascale computing systems, ultra-high-density memories would be required that consume low power to process massive data. Of the various memory devices, 3D-stacked DRAMs using TSVs are a perfect solution for this purposes. In addition to providing high capacity, these provide functional flexibility to the computing system by attaching a logic die in each 3D-stacked DRAM chip. However, the high capacity 3D-stacked DRAMs suffer from a significant loss of refresh power, which is solely required to maintain data. Although various schemes have been proposed to mitigate this issue, they cannot be adopted by commercial products due to compatibility issues. To tackle this issue, we propose EXTREME, which effectively reduces the refresh power of 3D-Stacked DRAMs. In order to retain the compatibility with OS, a simple page table manager is implemented at the logic die of 3D-stacked DRAM devices, which pins the page table to a specific memory space. The experiment results demonstrate that this reduces the refresh power at idle time by up to 98 percent with 16 KB of SRAM (static RAM) and 64 KB of DRAM register overhead for a 2 GB 3D-stacked DRAM device.

Molecular dynamics simulations were performed to investigate the effect of the enthalpy of mixing on the atomic level structure and plasticity of binary metallic glasses by using an ideal model potential. Whereas some model alloys with a strong positive enthalpy of mixing solidified into mixtures of microcrystalline domains of face-centered cubic or hexagonal close-packed crystal structures, the other alloys solidified into amorphous structures. Various structural properties of the amorphous alloys were analyzed as a function of the enthalpy of mixing interaction parameter. The deformation behavior of the amorphous samples was discussed in terms of atomic-level structural features such as the fraction of icosahedral clusters, the degree of short-range ordering and potential energies of atomic clusters in order to find a clue on the relationship between the mechanical properties and atomic structure of the amorphous alloys.

Cotton and silk fabrics were dyed with Houttuynia cordata extract using aqueous ethanol solution and the dyeing and post-treatment conditions were optimized to impart antimicrobial activity to the fabrics. The dried Houttuynia cordata can be extracted at for 3 hours using an aqueous ethanol solution containing 70%(w/w) ethanol. For the highest color yields. Both cotton and silk fabrics can be dyed at for 60min with 10g/L of NaCl under pH 4. Silk fabrics can be dyed to higher K/S than cotton fabrics. The color fastness properties of the dyed fabrics were good when either citric acid crosslinking or aluminum alum mordanting was carried out as a post treatment. The dyed silk and cotton fabrics with the post treatments showed excellent antimicrobial activity against both Staphylococcus aureus and Klebsiella pneumoniae.

Bulk metallic glass (BMG) shows higth strength, high elastic limit, corrosion resistance and good wear resistance and soft magnetic properties and has been considering as a candidate for new structural materials. But they show limited macroscopic plasticity and lack of tensile ductility due to highly localized shear deformation, which should be solved for real structural application. In this paper researches on the enhancement of plasticity of BMG were reviewed briefly. Introducing heterogeneous structure in glass is effective to induce more shear transformation zones (STZs) active for multiple shear band initiation and also to block the propagating shear band. Several methods such as BMG alloy design for high Poisson`s ratio, addition of alloying element having positive heat of mixing, pre-straining BMG and variety of BMG composites have been developed for homogenous distribution of locally weak region, where local strain can be initiated. Therefore enhancement of plasticity of BMG is normally accompanied with some penalty of strength loss.

1Department of Material Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749, Republic of Korea 2Nuclear Materials Safety Research Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353, Republic of Korea 3Division of Electron Microscopic Research, Korea Basic Science Institute, 113 Gwahangno, Yuseong-gu, Daejeon 305-333, Republic of Korea 4Liquid Processing & Casting Technology R&D Group, KITECH, Incheon 406-840, Republic of Korea

This study has extracted elements and related factors in the modernization of Hanok, using an evaluation method, and has also considered the possibilities of modern images using AHP analysis. As a result, first, the elements that form the urban landscape of historical and cultural environment have to be created by extracting elements from the subject standard for construction of the elements selected. As for the aspect of blending history, culture and environment, scenic and important architectural aspects were delineated. Second, based on selected components of the basic type of features and construction, roof types, vertical and horizontal elements were simulated after setting the criteria. Third, according to its historical cultural circumstances the man-made landscape and the traditional measure of the model, specific values of the elements for the formation of structures were evaluated by priority. A region characterized by old city houses constructed of objective elements can possibly be combined. In addition, a Hanok multi-family house fitted for modern life and a variety of models to develop and validate the possibility and utilization of this study can be expected.

Purpose: This study evaluated the preoperative and postoperative radiologic findings of patients with complete repairs after massive rotator cuff tears along with the incidence of re-tear and the clinical outcomes. Materials and methods: This study evaluated 33 cases who had open complete repairs for massive rotator cuff tears and these patients were followed up for more than 24 months. The clinical evaluation was performed according to the shoulder joint function test of the American Shoulder and Elbow Surgeons (ASES), and the degree of arthritis related to the massive rotator cuff tears was evaluated using the Hamada classification. Results: The ASES scores improved from 37.6 preoperatively to 85.6 postoperatively. The mean preoperative acromio-humeral interval (AHI) score was 6.5 mm, which increased to 9.3 mm immediately after surgery, and there was a decreased to 6.5 mm noted at the last follow up. The lower radiology stages of arthritis according to the classification showed better preoperative and postoperative results. Conclusion: An open complete repair as the surgical treatment for a massive rotator cuff tear showed satisfactory results for pain relief and an improvement in the shoulder joint function though re-tear after surgery.

Background To determine the association between lunate morphology and the scapholunate instability using radiographic images, and investigate the association between lunate morphology and scaphoid fracture location. Methods Between January 2003 and December 2011, we retrospectively evaluated the plain radiographs and computed tomography (CT) images of 70 patients who underwent surgical intervention for a scaphoid nonunion, in order to determine the association between lunate type (I or II) and scapholunate instability or scaphoid fracture location. We determined the scaphoid fracture location using the fragment ratio and measured the radiolunate angle and capitate-triquetrum (C-T) distance. Results A type II lunate was present in 68.6% (48 of 70 cases). Mean fragment ratio of fracture location was 50.6% in the type II lunate group and 56.2% in the type I lunate group (p = 0.032). Sixteen of the 70 patients had dorsal intercalated segmental instability (DISI) deformities. Nine of 22 cases showed DISI deformity in type I lunate and 7 of 48 cases showed DISI deformity in type II lunate (p = 0.029). However, there were no significant differences between the presence of DISI deformity and fracture location (p = 0.15). Morphologic comparisons by both plain radiography and CT indicated a mean C-T distance in the type I lunate group (22 cases) of 2.3 mm and 5.0 mm in the type II lunate group (48 cases). The C-T distances were significantly correlated with lunate morphology (p = 0.001). Conclusions A type II lunate was associated with low incidence of DISI deformity and proximal location of fracture in patients presenting with a scaphoid nonunion.

Estrogen-dependent transcriptional activation by estrogen receptor alpha (ERalpha) depends on the conformation of helices 3 and 12 in the ligand-binding domain. To better understand the function of helix 3 in ERalpha, we examined the role of charged residues, which are conserved in most steroid receptors in helix 3, in estrogen-dependent transactivation. The replacement of Asp-351 with lysine (D351K) or leucine (D351 L) completely abolished estrogen-dependent transactivation without affecting estrogen-binding, DNA-binding and homodimerization activities in ERalpha. The mutations dramatically reduced the ligand-dependent activation function 2 activity and impaired the ability of ERalpha to bind p160 coactivators. In addition, the D351K mutant effectively inhibited the transcriptional activation activity of wild-type ERalpha. Furthermore Asp-351 was required not only for the estrogen-dependent conformational change of wild-type ERalpha but also for the constitutive transcriptional activity and ligand-independent active conformation of ERalpha mutant Y537N. Similarly, in the orphan nuclear receptor called estrogen-related receptor 3 (ERR3), the replacement of Asp-273 (the corresponding amino acid to Asp-351 in ERalpha) with lysine abolished constitutive transcriptional activity of ERR3 without affecting DNA-binding activity and impaired the ability of the receptor to interact with p160 coactivators. These data suggest a role of Asp-351 in inducing and stabilizing the active conformation of ERalpha, and our results experimentally confirm the concept that Asp-351 in helix 3 interacts with the amide hydrogen of L540 in helix 12 to form a transcriptionally competent surface for binding p160 coactivators.

A design procedure for a structure's monitoring system using sensitivity analysis and a neural network is developed. The monitoring system is to be used to monitor damage to members critically affecting the overall safety of structures. Recently, many techniques for evaluating the damage of isolated members and models of simple structures have been investigated. However, actual structures are large, and their complex behavior may not be based on damage of isolated members or their simple models. To monitor large structures realistically, structures' data on behavior at many points need to be monitored. Identifying the optimal locations and numbers of these monitoring points and assessing the safety of the entire structure from the limited data are the monitoring system design problem. The procedure presented for this design problem is a two-step process. In the first step, using sensitivity analysis and damage-assessment techniques, individual members are ranked according to their influence on the failure probability of the entire structure or according to their effect on the abnormal behavior of the structure. Based on the rank, critical members are identified. In the second step, sensitivity analysis and a neural network are used to determine the optimal locations. In addition, the optimal number of sensors for monitoring damage to the critical members selected in step 1 is also suggested. Truss and frame examples are used to show the validity and applicability of the monitoring system design procedure.

Choristoma is a benign tumour defined as normal tissue in an ectopic location. Osseous choristoma, one subtype of this entity, occurring within the orbit has rarely been reported in the world literature. We report a 6-year-old girl with bilateral ocular osseous choristomas who presented with palpable nodules protruding from both upper lids. The radiological and clinical findings are described and previous reports are reviewed.

Purpose To descirbe a series of patients in which Thyroid Associated Orbitopathy (TAO) occurred after periocular surgery. Methods A retrospective case review of patients who developed TAO in close temporal association with periocular surgical interventions and presented at the orbital clinic from 1997 to 2004. History of previous thyroid abnormality and the lack of TAO signs and symptoms before surgery were reviewed and analyzed. Results Nine patients that developed TAO in association with periocular surgery were identified. All were women with an average age of 59.3years. (range: 45-75 years). The patients divided into two groups. Group 1 consisted of four patients who had previously been diagnosed with Graves' hyperthyroidism (GH). They ranged in age from 48 to 75 years (average: 58.8 years). The diagnosis of GH had been made an average of 50.5 months (range: 12-96 months) before presentation with TAO. Group 2 consisted of five patients who had no previous history of thyroid abnormality. They ranged in age from 45 to 74 years (average: 60.2 years). No patients had any signs or symptoms of TAO before their recent presentation. Conclusions Periocular surgery may lead to local inflammatory events that may contribute to the instigation of TAO in predisposed individuals.

The imputation of missing values is necessary for the efficient use of DNA microarray data, because many clustering algorithms and some statistical analysis require a complete data set. A few imputation methods for DNA microarray data have been introduced, but the efficiency of the methods was low and the validity of imputed values in these methods had not been fully checked. We developed a new cluster-based imputation method called sequential K-nearest neighbor (SKNN) method. This imputes the missing values sequentially from the gene having least missing values, and uses the imputed values for the later imputation. Although it uses the imputed values, the efficiency of this new method is greatly improved in its accuracy and computational complexity over the conventional KNN-based method and other methods based on maximum likelihood estimation. The performance of SKNN was in particular higher than other imputation methods for the data with high missing rates and large number of experiments. Application of Expectation Maximization (EM) to the SKNN method improved the accuracy, but increased computational time proportional to the number of iterations. The Multiple Imputation (MI) method, which is well known but not applied previously to microarray data, showed a similarly high accuracy as the SKNN method, with slightly higher dependency on the types of data sets. Sequential reuse of imputed data in KNN-based imputation greatly increases the efficiency of imputation. The SKNN method should be practically useful to save the data of some microarray experiments which have high amounts of missing entries. The SKNN method generates reliable imputed values which can be used for further cluster-based analysis of microarray data.