Theoretical studies on VPI-5. 3. The MS-Q force field for aluminophosphate zeolites

Aluminophosphate zeolite is an artificial material which shows strange hydrophilicity. We have been investigating the reason by quantum mechanics, and found that the hydrophilicity of this zeolite depended on the local geometric deformation, and speculated that the site-specific hydrophilicity might be explained by differences in the stiffness of the local deformation determined by the location with the pore structure. In order to test these ideas, we construct a reliable force field based on the new MS-Q approach developed by Demiralp, Cagin, and Goddard. Our force field well reproduces the experimental structure of VPI-5.     

A 250-Mb/s/pin, 1-Gb double-data-rate SDRAM with a bidirectionaldelay and an interbank shared redundancy scheme

This paper describes three circuit technologies indispensable for high-bandwidth multibank DRAM's. (1) A clock generator based on a bidirectional delay (BDD) eliminates the output skew. The BDD measures the cycle time as the quantity charged or discharged of an analog quantity, and replicates it in the next cycle. This achieves a 0.18-mm ², two-cycle-lock clock generator operating from 25 to 167 MHz with a 30-ps resolution. (2) A quad-coupled receiver eliminates the internal skew caused by the difference between a rise input and a fall input by 40%. (3) An interbank shared redundancy scheme (ISR) with a variable unit redundancy (VUR) efficiently increases yield in multibank DRAM's. The ISR allows redundancy match circuits to be shared with two or more banks. The VUR allows the number of units replaced to be variable. These circuit technologies achieved a 250-Mb/s/pin, 8-bank, 1-Gb double-data-rate synchronous DRAM     

Hyper-Kloosterman Sums and their Applications to the Coding Theory

The dual code of the Melas code is called the Kloosterman code. The weights of its codewords can be expressed by the Kloosterman sums, and are uniformly distributed with respect to the Sato-Tate measure. In this paper, the hyper-Kloosterman code C _m (q), a generalization of the Kloosterman code is defined, and the uniform distribution property is deduced using the hyper-Kloosterman sums when m is even and p− 1|m. Finally we discuss doubly-evenness for the weights in the binary case. It shows that we can construct infinitely many doubly-even codes in a non-trivial way. Received: October 30, 2000; revised version: February 28, 2001     

Secular change in characteristics of thyristors used in HVDC valve

The Hokkaido-Honshu HVDC link entered service in 1979 for the first phase (150 MW, 125 kV-1200 A) and in 1980 for the second phase (300 MW, 250 kV-1200 A) and has since been operating in good condition. In the Kamikita converter station situated on the Honshu side, the thyristor valves for the first and second phases use 1344 thyristors rated 4 kV-1.5 kA. To examine secular changes in the characteristics of thyristors and estimate their life expectancy, we picked up eight thyristors from the thyristor valves, measured the main characteristics and compared measurements with the corresponding values measured before they entered service. Further, two thyristors were subjected to temperature and voltage acceleration tests to check for a change over time of leakage current. From the results of these investigations it was verified that the thyristors that have been in service for 16 years have the characteristics and service life equivalent to those of the new ones. But further investigation is required as to the change of turn-off characteristics     

Cardiac malignant pheochromocytoma with bone metastases

A patient with malignant cardiac pheochromocytoma with bone metastases is described. The primary tumor was located between the pulmonary trunk and the left atrium, while metastatic lesions were found in the iliac bones. Treatments with antihypertensive agents, alpha-methylparatyrosine, and combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine partially improved the patient's symptoms, catecholamine levels, and the metastatic lesion of the iliac bones. However, the primary tumor in the heart progressively increased in size and the patient died of disseminated intravascular coagulation and other various complications about 4 years after the diagnosis of the disease.     

A case of predominantly right-temporal lobe atrophy with disturbance of identifying familiar faces

A right-handed 72-year-old man (I.K.) who complained of difficulty identifying familiar faces was investigated on a series of tests of face perception (face matching, recognition of age and sex, and meaning of facial expressions), facial identity (faces of families and famous persons as retrograde ones and his doctor's faces as anterograde ones) and other neuropsychological abilities. His scores of face perception tests were normal or mildly disturbed. His memory performances measured with WMS-R and Rey-Osterrieth figure were normal. But he could identify none of anterograde and retrograde faces and failed to experience any familiarity with those faces. In addition, he could not recognize none of voices of family members and a doctor, despite of being able to recognize about the age and sex of voice. On the other hand, he could describe personalities of his family members and doctors, but knew none of famous people. Memory for personal events in the recent and remote past was well preserved, while that for social events was severely disturbed in both past. In addition to impairment of identification of familiar faces, he had severe problems with identifying famous common buildings and animals. He also presented Gogi (word meaning) aphasia and impairment of semantic memory for some common objects. Tyrrell et al. reported a similar case and McNeil et al. examined the patient on covert recognition of face in detail. On their task, he showed no covert effects and they attributed the result to impairment of face recognition units themselves. Their way of thinking seems to give an explanation of I.K.'s disturbance of anterograde and retrograde memory for faces.(ABSTRACT TRUNCATED AT 250 WORDS)     

Selective catalytic reduction of N2O by C3H6 over Fe-MFI

The catalytic activities of Fe-MFI (88% exchange) and Cu-MFI (122% exchange) zeolite catalysts for the decomposition and mainly the selective reduction of nitrous oxide by propene have been studied in the temperature range from 523 to 773 K. In the presence of oxygen and water vapor, both materials reveal strong retardation of their activity. When propene is added as reductant, Fe-MFI showed very high activity even in the low-temperature region and at low propene concentrations, whereas Cu-MFI is strongly deactivated. This revised version was published online in July 2006 with corrections to the Cover Date.     

An efficient algorithm for optimal generation mix taking into account fuzziness of decision making and planning parameters

This paper presents an efficient computational algorithm for selecting the optimal generation mix under uncertain circumstances. Subjective, experiential or linguistic uncertainties are selected from among various uncertainties, i.e., we treat fuzziness in generation expansion planning. The fuzziness can be divided into: (1) the fuzziness of decision making; and (2) the fuzziness of some planning parameters, such as load growth, fuel price, and so on. Both classes of fuzziness are integrated into a fuzzy decision based on fuzzy sets theory, and then the optimal generation mix can be determined by the Fuzzy Dynamic Programming (FDP) technique. The proposed method, which is based on the dynamic programming technique, is extended by using the Bellman-Zadeh maximizing decision. In the method, each generation technology and generation capacity are selected as a stage and state, respectively. The proposed method can easily accommodate not only the fuzziness but also many constraints of generation expansion planning, such as integer solutions of unit capacities, condition of existing units, and so on. Furthermore, the arbitrary shape of membership function can be used. The effectiveness and feasibility of the proposed method are demonstrated on a typical power system model.