Somatic Embryogenesis of Phalaenopsis

The growth and differentiation of a unique Phalaenopsis callus was characterized. The callus was determined to be friable and embryogenic producing plantlets which matured and flowered. In contrast to other orchid calli reported previously, the callus was unique in its extreme friability and undifferentiation with no trace of organization. The callus was maintained on a modified Vacin and Went medium containing sucrose 20.0 g*liter-1 supplemented with coconut water (CW) 150 ml-liter-1 without any morphological change for more than five years. Analyses of callus growth (fresh weight) showed that the callus had an extremely low growth rate, which was not affected by sucrose levels between 2.5 to 30.0 g-liter-1. Although CW stimulated callus growth, lAA (indole-3-acetic acid) or BA (benzyl adenine) was not effective. Somatic embryogenesis was induced by lowering sucrose level to 2.5 g*liter-1 or deletion of sucrose and supplementing with CW. Callus turned green and subsequently formed numerous embryoids at periphery of green callus. The development of embryoids into plantlets morphologically resembled germination of zygotic embryos of Phalaenopsis. Sucrose (20.0 g-liter-1) inhibited greening and somatic embryogenesis. Sugar inhibition of greening and somatic embryogenesis was not overcome by transfer of callus from auxin-enriched medium to auxin-free medium or increasing nitrogen level, but only by reduction of carbohydrates available in medium. Pretreatment with lAA or NAA (a-naphthaleneacetic acid), and supplement of CW, casein hydrolysate (CH), glutamic acid or glutamine with 2.5 g-liter-1 of sucrose were marginally effective in promoting embryogenesis. Readily utilizable monosaccharides, glucose, fructose, mannose, ribose, xylose and disaccharide, sucrose at 20.0 g-liter-1 were inhibitory, while other disaccharides, multisaccharides and sugar-alcohols supported greening and somatic embryogenesis. Amylose (20.0 g-liter-1) was the most effective in induction of embryogenesis among carbohydrate sources. Regeneration of plantlets through indirect somatic embryogenesis is shown to be a viable pathway for clonal propagation of recalcitrant Phalaenopsis orchids

A Case Analysis of Explaining the Main Factors that Contribute to ROK\u27s Decision Making in Procurement of Defense Articles

The purpose of this research was to explore the various factors that contribute to ROK’s decision making in procurement of foreign countries defense articles. South Korea is one of the largest weapon purchasers from the U.S. and needs a more self-reliant defense force that can maintain its security with its own authority under the current cease-fire situation. Thus, this study focused on identifying the main factors to consider in deciding whether to purchase a major defense weapon system from other countries. Through the interview of experts who participated in specific weapon programs, thirteen specific factors were evaluated including Interoperability, Offset valuation, Mission performance capability, Integrated Logistics Support (ILS), Lifecycle, Timely Deployment, Depot Maintenance, National Security, U.S.-ROK Alliance, Northeast Asia Strategy, Defense Budget Levels, ROK Political Environments and Trends in Public Opinion in order to explain what the essential elements in the process of ROK’s decision making are. The focus of this thesis is to identify the critical factors to support foreign weapon programs. Finally, this study revealed that mission performance capability, interoperability, integrated logistics support, and offset valuation were primary considerations in the process of ROK’s decision-making. This information will provide valuable lessons learned which can be applied to future ROK military defense procurement

Cancelable ECG Biometrics using Compressive Sensing-Generalized Likelihood Ratio Test

Electrocardiogram (ECG) has been investigated as promising biometrics, but it cannot be canceled and re-used once compromised just like other biometrics. We propose methods to overcome the issue of irrevocability in ECG biometrics without compromising performance. Our proposed cancelable user authentication uses a generalized likelihood ratio test (GLRT) based on a composite hypothesis testing in compressive sensing (CS) domain We also propose a permutation-based revocation method for CS-based cancelable biometrics so that it becomes resilient to record multiplicity attack. In addition, to compensate for inevitable performance degradation due to cancelable schemes, we also propose two performance improvement methods without undermining cancelable schemes: a self-guided ECG filtering and a T-wave shift model in our CS-GLRT. Finally, our proposed methods were evaluated for various cancelable biometrics criteria with the public ECG-ID data (89 subjects). Our cancelable ECG biometric methods yielded up to 93.0% detection probability at 2.0% false alarm ratio (PD*) and 3.8% equal error rate (EER), which are comparable to or even better than non-cancelable baseline with 93.2% PD* and 4.8% EER for challenging single pulse ECG authentication, respectively. Our proposed methods met all cancelable biometrics criteria theoretically or empirically. Our cancelable secure user template with our novel revocation process is practically non-invertible and robust to record multiplicity attack

DATID-3D: Diversity-Preserved Domain Adaptation Using Text-to-Image Diffusion for 3D Generative Model

Recent 3D generative models have achieved remarkable performance in synthesizing high resolution photorealistic images with view consistency and detailed 3D shapes, but training them for diverse domains is challenging since it requires massive training images and their camera distribution information. Text-guided domain adaptation methods have shown impressive performance on converting the 2D generative model on one domain into the models on other domains with different styles by leveraging the CLIP (Contrastive Language-Image Pre-training), rather than collecting massive datasets for those domains. However, one drawback of them is that the sample diversity in the original generative model is not well-preserved in the domain-adapted generative models due to the deterministic nature of the CLIP text encoder. Text-guided domain adaptation will be even more challenging for 3D generative models not only because of catastrophic diversity loss, but also because of inferior text-image correspondence and poor image quality. Here we propose DATID-3D, a domain adaptation method tailored for 3D generative models using text-to-image diffusion models that can synthesize diverse images per text prompt without collecting additional images and camera information for the target domain. Unlike 3D extensions of prior text-guided domain adaptation methods, our novel pipeline was able to fine-tune the state-of-the-art 3D generator of the source domain to synthesize high resolution, multi-view consistent images in text-guided targeted domains without additional data, outperforming the existing text-guided domain adaptation methods in diversity and text-image correspondence. Furthermore, we propose and demonstrate diverse 3D image manipulations such as one-shot instance-selected adaptation and single-view manipulated 3D reconstruction to fully enjoy diversity in text.Comment: Accepted to CVPR 2023, Project page: https://gwang-kim.github.io/datid_3d

Inflation Targeting and Relative Price Variability: What Difference Does Inflation Targeting Make?

This article studies the effects of inflation targeting (IT) on relative price variability (RPV) using a data set of twenty countries comprising both targeters and nontargeters. We find that a decline in mean inflation after IT adoption is not necessarily associated with a similar fall in RPV and that what matters most for the structural changes in RPV is the initial inflation regime prior to the adoption of IT rather than IT adoption itself. IT adoption impacts the shape of the underlying relationship between inflation and RPV in countries with initially high inflation rates, moving it from monotonie to the U-shaped profile observed consistently for countries with low-inflation regimes. The minimum point of this U-shaped curve is indicative of the public\u27s expectations of inflation and is very close to the announced target for inflation in most of the countries we study