Analysis of the current distortion factor of a three‐phase,three‐wire system

In a balanced three‐phase system, the three‐phase current distortion factor of three‐phase ac power sources has been expressed by applying the conventional single‐phase current distortion factor, which is defined for a single‐phase system. However, in an unbalanced three‐phase system, it is difficult to express the three‐phase current distortion factor for distorted three‐phase ac currents by means of the conventional single‐phase current distortion factor. For instance, the conventional current distortion factors for three‐phase ac currents are usually different from each other in the unbalanced three‐phase system. To solve the above problem, this paper proposes a novel definition of the three‐phase current distortion factor. The proposed three‐phase current distortion factor is quite effective for the unbalanced three‐phase system as well as the balanced three‐phase system. © 2000 Scripta Technica, Electr Eng Jpn, 131(4): 1–10, 2000     

Incremental learning of gestures for human–robot interaction

For a robot to cohabit with people, it should be able to learn people’s nonverbal social behavior from experience. In this paper, we propose a novel machine learning method for recognizing gestures used in interaction and communication. Our method enables robots to learn gestures incrementally during human–robot interaction in an unsupervised manner. It allows the user to leave the number and types of gestures undefined prior to the learning. The proposed method (HB-SOINN) is based on a self-organizing incremental neural network and the hidden Markov model. We have added an interactive learning mechanism to HB-SOINN to prevent a single cluster from running into a failure as a result of polysemy of being assigned more than one meaning. For example, a sentence: “Keep on going left slowly” has three meanings such as, “Keep on (1)”, “going left (2)”, “slowly (3)”. We experimentally tested the clustering performance of the proposed method against data obtained from measuring gestures using a motion capture device. The results show that the classification performance of HB-SOINN exceeds that of conventional clustering approaches. In addition, we have found that the interactive learning function improves the learning performance of HB-SOINN.     

A long-term follow-up study of serial magnetic resonance images in patients with delayed encephalopathy after acute carbon monoxide poisoning

We report a case of vasculitis in a 67-year-old woman who successively developed over a four-month period clinical manifestations suggestive of rheumatoid arthritis, lupus, sicca, syndrome and finally giant cell arteritis. All her symptoms resolved promptly upon discontinuation of enalapril and none recurred over the five-year follow-up period. The only residual manifestation is Jaccoud's arthropathy of the hands.     

High-field conduction and carrier traps in polyethylene copolymerized with various monomers

The electrical breakdown and electrical conduction of ethylene copolymers have been studied. The electric strength of ethylene copolymers containing an optimum content of halogen moieties such as bromophenyl and fluoroethylene groups was found to be higher than that of LDPE over the wide temperature range from ?196°C to 90°C. Also, conduction currents in the copolymers were suppressed at high electric fields. X-ray-induced thermally stimulated currents (TSC) revealed that halogen comonomers act as carrier traps with a depth of about 0.4 eV. Consequently, the introduction of comonomer-containing halogen groups into polyethylene suppresses electron acceleration as a result of an increase in trapping and scattering of conduction electrons. This leads to an increase in electric strength which is determined by the electron avalanche breakdown.     

Myocardial recovery through ECMO after repair of total anomalous pulmonary venous connection: the importance of left heart unloading

A 7-day-old boy who had been placed on extracorporeal membrane oxygenation on his second day of life developed biventricular failure after undergoing surgical repair of a supracardiac variant of total anomalous pulmonary venous connection. Extracorporeal membrane oxygenation was again necessary for postoperative cardiopulmonary support. However, severe left ventricular failure made it imperative to leave the vertical vein open during support in order to decrease pressure on the left ventricle. The patient was successfully weaned from extracorporeal membrane oxygenation on day 8 after surgery and discharged from the hospital on day 23.     

Synthesis and characterization of europium(II)-holoborates,Eu2B5O9Cl and Eu2B5O9Br

Europium(II)-haloborates, Eu₂B₅O₉Cl and Eu₂B₅O₉Br, were synthesized and characterized by X-ray analysis, magnetic susceptibility and luminescent spectral measurements. The chloroborate Eu₂B₅O₉Cl crystallizes in the tetragonal system, D⁶₄-P4₂2₁2, with cell dimensions: a=11.349(4), $\text{c}\text{=6.500(4)}\text{A}\text{?}$ and Z=4, and Eu₂B₅O₉Br in the orthorhombic system, C¹⁰_2v-Pnn2 or D¹²_2h-Pnnm, with cell dimensions: a=11.503(3), b=11.382(3), $\text{c}\text{=6.484(2)}\text{A}\text{?}$ and Z=4. Both of them were paramagnets with paramagnetic Curie temperature at about ?1 K, and band emissions peaking at about 430 and 435 nm which were based on a 4f⁷-4f⁶5d transition of Eu²⁺ ion were observed on Eu₂B₅O₉Cl and Eu₂B₅O₉Br, respectively.     

The oxygen snoek damping and an abnormal peak of neutron-irradiated vanadium

Measurements of low-frequency internal friction and electron microscope observations were made on neutron-irradiated vanadium with various oxygen contents. Irradiation was carried out at about 60°C to a fast fluence of $\text{2 × 10}{}^{17}$ or $\text{5 × 10}{}^{19}$ n/cm² ($\text{E ? 1 MeV}$). The oxygen Snoek damping was decreased by irradiation and post-irradiation annealing below 200 or 250° C, while it began to recover by annealing above this temperature. Complete recovery was attained by 30 min anneal at 450°C in the case of the lower fluence, whereas in the other case it was not observed after the same treatment. The results of electron microscope observations were consistent with those of internal friction measurements. The specimens irradiated to $\text{5 × 10}{}^{19}$ n/cm² showed an abnormal peak after annealing above 250°C near the nitrogen Snoek temperature. The height of this peak, $\text{P}{}^{\mathrm{?1}}{}_{\mathrm{<mtext>max</mtext>}}$, was expressed as $\text{P}{}^{\mathrm{?1}}{}_{\mathrm{<mtext>max</mtext>}}$ ∝ exp ($\text{2.72 × 10}{}^3\text{/RT}$) $\text{Q}{}^{\mathrm{?1}}{}_{\mathrm{<mtext>max</mtext>}}$, where $\text{Q}{}^{\mathrm{?1}}{}_{\mathrm{<mtext>max</mtext>}}$ the heiβht of the oxygen Snoek damping after each annealing. The mechanism for radiation-anneal hardening and the abnormal peak were considered in the light of these experiments.     

Characteristics of phospholipids in human lung carcinoma

Human lung carcinoma tissues with histological types of adenocarcinoma, squamous cell and small cell carcinoma were investigated for phospholipids. There were marked differences in the phospholipids between these lung carcinoma and normal lung tissue. A marked decrease in saturated phosphatidylcholine (PC), predominantly the dipalmitoyl species, was noted in the carcinoma, although they still contained 17–20% of the saturated classes. The lung carcinoma contained less phosphatidylglycerol (PG) and lyso-bis-phosphatidic acid and more cardiolipin and phosphatidylinositol (PI) than the normal lung tissue. These alterations observed in the lung carcinoma apppeared to show that they lose the characteristic feature of phospholipids in the lung tissue. The differences in the lipid composition among different cell types of lung carcinoma were also noted. The squamous cell and small cell carcinoma contained more triacylglycerol and relatively higher dienes I (monoenoic-monoenoic) and lower dienes II (saturated-dienoic) of PG, respectively, as compared to adenocarcinoma.     

Copper-Alkali Ion Exchange of Alkali Aluminosilicate Glasses in Molten CuCl—An Ion Exchange Controlled by the Cu+→Cu2+ Oxidation Reaction in Glass

The kinetics of copper-potassium ion exchange of potassium aluminosilicate glass have been investigated in molten CuCl at 550°C in air and nitrogen. The presence of oxygen dissolved in molten CuCl has a great effect on the Cu-K ion-exchange kinetics, i.e. ion exchange in nitrogen is controlled by the interdiffusion process of Cu⁺ and K⁺ in the glass, whereas ion exchange in air seems to be controlled by the Cu⁺→Cu²⁺ oxidation reaction.