A Next‐Generation Distribution Automation System Using IEC 61850 GOOSE and Section Switches with Sensors

More and more dispersed power sources will be introduced to achieve a low‐carbon society. However, many problems may occur as a result of excessive introduction in the current power system. For example, delays or failures of fault detection may occur due to a decline in protective relay sensitivity. This paper proposes a new system of protective relays for distribution lines using section switches with sensors to solve the problem. In addition, experimental results on the proposed system composed of Intelligent Electronic Devices based on IEC 61850 are presented.     

钢水流动对连铸坯初期凝固的影响

为了定量把握结晶器中的钢不流动、钢水过热度及结晶器传热阻力对初期凝固坯壳的凝固不均一的影响，利用水冷铜板的浸渍实验，测定了各种铸造条件下的凝固坯壳厚度、凝固不均一度及对枝晶偏角；利用水力模型实验，并对实机铸坯的凝固组织分析，ＥＰＭＡ对负偏析带的线分析，得出了在结晶器中凝固坯壳上负偏析带的产生原因。其主要结果是：①随着钢水８流动速度及过热度的增加，凝固坯壳度减少，凝固坯壳不均一度增大；②缓冷结晶器可     

NATTO BACILLUS CONTAINS A LARGE AMOUNT OF WATER-SOLUBLE VITAMIN K (MENAQUINONE-7)

Bacillus natto (Bacillus subtilis natto) was cultivated, and an analysis was conducted after performing lysozyme treatment and water extraction of the culture supernatant and the B. subtilis natto cells. The intracellular existence of a large amount of water‐soluble vitamin K (Menaquinone‐7: MK‐7) was established. The existence of small amounts of other types of vitamin K2 including MK‐4 and PK was also confirmed in the culture solution (water‐soluble fractions). The amount of water‐soluble menaquinone‐7 in Bacillus was 85 µg/g wet weight of the bacteria, and the amount was equivalent to more than 100 times as much as that contained in the culture solution (0.02 µg). Gel filtration using Sephacryl S‐200HR revealed that the molecular weight of the water‐soluble menaquinone‐7 is approximately MW 200,000, and isoelectric focusing revealed a behavior similar to that of protein, with a pI of about 4.2. A rabbit antibody was prepared with this water‐soluble vitamin K as the antigen. By using the Ouchterlony method, the antibody showed a reaction (precipitation line) with the water‐soluble menaquinone‐7 prepared from both the intracellular fraction and the extracellular culture solution, and it was found through the antigen–antibody reaction that the menaquinone‐7 disappears from the supernatant of the reactant (the water‐soluble menaquinone‐7 is thus neutralized). Based on these results, it was inferred that the vitamin K produced by B. subtilis natto becomes water‐soluble by forming an intracellular complex with protein and is released in the extracellular fraction during the culture process.     

Note on ‘ Solution of the aggregate production planning problem in a multi-stage-multi-product manufacturing system using functional space analysis and quadratic programming approaches ’

The recent paper of Teny and Kochhar (1983) concluded that the solution calculated by using the functional space analysis technique presented by Hitomi and Nakamura (1976) is inferior to that rendered by the quadratic programming approach (Bcale 1968). This paper shows the contradiction included in their discussion and denies the above conclusion. Functional space analysis is also developed to obtain a mixed-integer solution.     

Output regulator problem of a nuclear reactor system

A control problem of distributed reactor systems is investigated. After kinetic equations are expanded into Kaplan modes, the output regulator with structural stability is applied to the spatial mode system. In particular, the fundamental mode is regarded as an exogeneous input signal to the spatial control system due to a variation of control rods from the power control system. The output to be regulated is the neutron flux deviation from the equilibrium value at some specified points where the fuels in burn-up are located. Some numerical simulation results are presented to show the effectiveness of the proposed method.     

Decision analysis for determining the optimum planning horizon in aggregate production planning: Part 2: Difference between planning horizons in weekly and in monthly schedulings

The effects of changing a unit time length of a planning horizon from a month to a week on the optimum planning horizon were examined by calculating the optimum planning horizon through the methods proposed by Nagasawa, Nishiyama, and Hitomi (1982). It was found that the optimum planning horizon decreased by 20-30% in calendar time when the unit time length was changed from a month (monthly scheduling) to a week (weekly scheduling). However, the degree of this decrease was much smaller than the (65% shown by Bernardo (1978 BERNARDO , J. J. , 1978 ], The effect of inventory and production costs on the optimal planning horizon , International Journal of Production Research , 16 , 103 .[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), and it followed that the optimum planning horizon largely increased in the number of periods with this change of the unit time length. It was also clarified that the large amount of the decrease shown by Bernardo was derived on the basis of the erroneous analysis of the relation between cost coefficients and the unit time length. Consequently, weekly scheduling was not always preferred to monthly scheduling     

Crystal Structures and Mechanism of Thermal Expansion of High Cordierite and Its Solid Solutions

The crystal structure of high cordierite and that of high cordierite solid solutions containing either Mn or Ga or Ge were refined. The structural changes caused by substitutions and the characteristic features of deformations of each T1O₄, T2O₄ tetrahedron and MO₆ octahedron were clarified. Thorough crystal chemical considerations led to a conclusion that the structure of Mn-bearing solid solution at room temperature may be regarded as a model structure of high cordierite at an elevated temperature. On the basis of the thermal expansion mechanism derived from this consideration, the thermal expansion behavior of the solid solutions is presented.     

Development of Corrosion‐Resistant Pressure Sensor with Semiconductor Strain Sensor

In automotive and industrial fields, pressure sensors are a key component for precisely controlling the mechanical systems. Conventional micro electro mechanical system (MEMS)‐based pressure sensors have an advantage in noise resistance, because both strain gauges and control circuits are integrated in one chip. However, the MEMS‐based pressure sensors are generally fabricated on an Si substrate, and have a low stability against various active gases. Thus, we have newly proposed a pressure sensor which consists of an Si‐based strain sensor set on a stainless steel diaphragm with a high stability against the active gases. The key technology is that a Koval plate is inserted between the strain sensor and the stainless steel diaphragm, for preventing the breakage or the delamination of the strain sensor at the bonding interface due to a difference in thermal expansion. Structure of the sensor including the shape and the size of Koval plate and the assembly position of the strain sensor were designed using structural simulation and experiments. Eventually, the 2.8 mm wide and 0.17 mm thick Koval beam was bridged on the stainless steel diaphragm for efficiently transmitting the diaphragm deformation to the strain sensor. The strain sensor was assembled at the edge of Koval beam with a glass bonding technique. Consequently, the developed pressure sensor has achieved a small dispersion of less than 1% F. S. in a temperature range from 0 °C to 85 °C.     

Optimal design of FIR linear phase digital filters via convex quadratic programming method

Many methods exist for designing FIR linear phase digital filters by using various optimization techniques. An optimization design method via the convex quadratic programming method is investigated in this paper. The aim of this method is to design digital filters with certain desired frequency responses that keep the passband ripple to a minimum while maintaining a balance between opposite characteristics of frequency responses, i.e. the narrow transition band and the great stopband attenuation. In order to verify the effectiveness of this method, low-pass filters are designed and comparison studies with other typical optimization methods are given.