Highly diastereoselective Michael addition of alpha-hydroxy acid derivatives and enantioselective synthesis of (+)-crobarbatic acid.

[reaction: see text]. Michael addition of enolates of 2a and 2b to alpha,beta-unsaturated esters took place selectively on different faces (Si and Re, respectively) of the double bond to give the corresponding products 4 and 5, respectively, with >98% de. Subsequent hydrolysis of these Micheal adducts gives 3,4-disubstituted gamma-lactones with high enantiomeric excesses.

Virtual endoscopy using surface rendering and perspective volume rendering.

Noninvasive virtual endoscopy is a new method of diagnosis using computer processing of 3-D image data sets (such as CT or MRI scans). Conventionally, two methods have been used in virtual endoscopy. One is 3-D surface rendering method. 3-D surface of human organs can be explored in real time by using this method, but surface rendering algorithm has disadvantages such as the low quality of visualized image and the loss of the volume data. The other is perspective volume rendering method. The power of perspective volume rendering is that the intrinsic 3-D richness of the volume data is preserved. However, there are the difficulty in planning flight-path and the disability of real time flight for a computationally intense procedure. This paper presents virtual endoscopy using both surface and perspective volume rendering. By combining each merits of two methods, a user can not only process virtual endoscopy interactively in real time but also view lossless and high-resolution image using the flight path defined by surface rendering. As a result, the use of common fly-paths removes the burden to define a flight-path in conventional perspective rendering method. Also 3-D object is explored in real time and viewed as lossless and detail cine sequences.

Development of a virtual speaking simulator using Image Based Rendering.

The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology has enabled the use of virtual reality (VR) for the treatment of the fear of public speaking. There are two techniques for building virtual environments for the treatment of this fear: a model-based and a movie-based method. Both methods have the weakness that they are unrealistic and not controllable individually. To understand these disadvantages, this paper presents a virtual environment produced with Image Based Rendering (IBR) and a chroma-key simultaneously. IBR enables the creation of realistic virtual environments where the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma-keys puts virtual audience members under individual control in the environment. In addition, real time capture technique is used in constructing the virtual environments enabling spoken interaction between the subject and a therapist or another subject.

The development of the virtual reality system for the treatment of the fears of public speaking.

The fear of public speaking is a kind of social phobias. The patients having the fear of public speaking show some symptoms like shame and timidity in the daily personal relationship. They are afraid that the other person would be puzzled, feel insulted, and they also fear that they should be underestimated for their mistakes. For the treatment of the fear of public speaking, the cognitive-behavioral therapy has been generally used. The cognitive-behavioral therapy is the method that makes the patients gradually experience some situations inducing the fears and overcome those at last. Recently, the virtual reality technology has been introduced as an alternative method for providing phobic situations. In this study, we developed the public speaking simulator and the virtual environments for the treatment of the fear of public speaking. The head-mounted display, the head-tracker and the 3 dimensional sound system were used for the immersive virtual environment. The imagery of the virtual environment consists of a seminar room and 8 virtual audiences. The patient will speak in front of these virtual audiences and the therapist can control motions, facial expressions, sounds, and voices of each virtual audience.