In the present paper, it is argued how to deal with analytical and computational solutions of searchlight problem on flat terrain bounded below by a diffuse reflector. It is shown that the angular distribution of radiation emergent from a point source on top of the turbid plane-parallel atmosphere of finite thickness is discussed by embedding the problem within a family of parameters.

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Hayabusa returned to Earth on June 13, 2010, becoming the world's first explorer to complete a round-trip voyage to an asteroid. After being released from the spacecraft, the sample return capsule landed in the Woomera Prohibited Area in the desert of South Australia. The capsule recovery team from JAXA found the capsule within 1 h of its landing. The beacon tracking system that was developed by JAXA played an important role in the tracking and discovery of the sample return capsule. The system has flexibility regarding the landing position of the capsule, because it does not rely on primary radar. In this paper, we describe the beacon tracking system and evaluate the system by discussing the results of preliminary examination and of operation on the day of re-entry.

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On the basis of questionnaire returned from about 30 fishing boats which operated for the saury (Cololabis saira) off Northeastern Region in 1950 and 1951, relationship between catch per boat-day and technical factors for fishing such as size of boat, and efficiency of equipments was analyzed. Since saury lift netters are engaged in other types of fishery during the offseason, boat-day catch among competing fishing units may as well be affected by fishermen's economic dependency based on annual income for each fishing boat was inquired of, and made available by, fishermen who cooperated in the survey.
The study indicated that factors which had a positive correlation with the boat-day catch were the size of boat in term of gross tonnage, economic dependency, powers of fishing light and , and size of net (Tables 1 to 3 and Figs. 1, 2).
The questionnaire returned revealed that the boat-day catch had a positive correlation with two items out of seven means the fishermen relayed on in choosing a fishing ground for every trip. They were combinations of items 1 and 5, radio broadcast of fishing conditions and data of current and water temperature provided by local service agencies, respectively (Figs. 3 to 5).
In locationg a school of fish, advantageous combinations among six technical items inquired of the fishermen were: 2) use of fish finder, 4) detecting an area with a favorable water temperature for the fish, and 5) search for water boundary (Figs. 6 to 8). The results suggest that those boats which combined relatively new kinds of information and more advanced technical means for their use seem to have had a higher catch per boat-day than their fellow fishing boats.

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In the present paper, it is discussed how to treat with the analytical and numerical solutions of searchlight problem with faint background light on flat terrain bounded below by a diffuse reflector. It is elucidated that the angular distribution of radiation emergent from the top of the turbid slab of finite thickness with a point source on top is discussed by imbedding the problem within a family of parameters, allowing for the numerical solution via Monte Carlo method.

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In the experiment, to study quantitatively the effect of sweeping membranous light or flashing light on the swimming behaviour of fish, the movement of fish school (yellowtail, body length 40cm) in the water tank (10m×7m, 1m depth) was observed every five seconds.
As the results, comparing the swimming speeds between the condition with sweeping membranous light and the condition without it, there was a remarkable lowering of the swimming speed under the condition with sweeping light, And this suppression effect was stronger with higher luminous intensity.
From the data of these results, it was suggested theoretically that 37 or more lx of irradiation intensity of the sweeping membranous light on the water surface might have maximum effects on the fish movements in a dark environment.

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従來探照燈用反射鏡は比較的光學的能率 (Optical Efficiency) の方面を八ヶ間敷く見て製造されて居たものである。それを換言ずれば曲面の性質を幾何學的に八ヶ間敷く云ふ事になる。從來列國の反射鏡製造會社はそれに力を入れて居た。故に各會杜とも相當の品を作り出す様になる迄には製造工場としての相當長年月の経験を練つて來たものである。則ち一夜作りの工場では斯る反射鏡は製造し得ないと云ふ課になるのである。則ち第一章及第二章では其事實を明白にした。故にそれを製出する工場は製作技能を低下させぬ様に、軍用として今差常り必要の無い品物でも不噺に製造を綾けて居なければならない事になるのだ。それがもし軍用以外に用途のない品物であるとすれば、斯る不漸の製造は随分不経濟な話である。然るに外國製造會杜從來の製造方法は斯る精密工業に窺するものであるに拘らず、産出した反射鏡は軍用以外に用途がない。故に著者は先づ第四章に於て、果して斯る光學的能率檜進のみに走る事が探照燈用反射拾としての性能の上より見て必要訣くべからざるものなるや否や銀明削にする爲めに探照燈用反射拾としての性能を論じた。両して其結果として反射拾の光學的能率上斯る僅小なる進歩が探照燈用反射鏡としての照射能力の上に影響する所極めて微細なるものである事を論じ、更に將來に残れる光學的能率上の進歩の拾地が探照燈用としての照射能力増進の上に殆んど影響せざるものである事を明白にした。一方に於て者者は大氣の光吸牧の影響と光波の波長との關係を論究し、それによつて鏡面を光の波長の上より特種の性質を持たしめるならば優に人間の網膜に感じ得る程度の照射能力の差異を與へ得るもので、りる事を確め、それによつて將來の進歩の蝕地が硝子鏡よりも寧ろ金屬鏡の方にある事を結論した。則ち著者は探照燈用反射鏡製造方法研究上の將來の望みを、長波長光線を射出し得る金艦鏡の上に置き夫れが製造方法研究問題として
1.) 「例へ光學的能率が探照燈用ごしての照射能力の上に影響を及ぼさざる程度にまで低下するも、これが爲めに特種精密工業みしての不噺の訓練を要せず、寧ろ不用意の中に一朝の有事に際して直ちに生産し得る方法」てう問題は今日の如き軍和時代に於て國家経濟上極めて重要なる研究問題である事を述べ、2.) 「反射鏡製造が從來列國製造働出く於て保守せらるる如き特種精密工業に馬し其技能をして低下せしめざる爲めに、職箏の有無に拘らず不筋の製造緩績を要ずるものみせば、それに仍て産出せらるる反射鏡は軍用以外今一段の精密を要する用途に適するものたらしむる製造方法」に向つて研究すべきである事を論述した。然るに此
1.) 及び
2.) の要求に應じ得る製造方法をして從來列國反射鏡會社が保守し來れるものの中に登見せんとするも、それは不可能であつてそれは一つに著者の発見に拘る反射鏡製造方法中第本章に示す方法が 2) 、の要求に應じ得るものであり第六章に示す方法が 1) 、の要求に適するものである事を明白にしたものである。

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The most necessary condition to save a man who has fallen overboard is to detect him as soon as possible. The fishermen are usally wearing a rubber coated raincoat and boots during fishing operations. The color of their protective clothing is almost all black. In order to focus on the relation between detection and color of the gear, the differece in visibility for 7 kinds of colored things was experimentally investigated from sunset to evening. From the result of this experiment, it was found that black was not so advantageous as the other colors, even for the detection of a man overboard, in the early stages.

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Atomization appeared to be the best means of obtaining pre-alloved powders without applying a limitation on composition. However, difficulty in the control of particle shapes has restricted the utilization of pre-alloyed powders produced by that process. The investigation has been therefore made on the water atomization of copper alloys, and subsequently the physical properties of the powders and of their pressed compacts were examined.
The results were summarised as follows : -
(1) Molten copper alloys atomized with water become the irregular particles, and this leads to be low apparent density.
(2) To facilitate to produce compacts of high green strength, it may be necessary for atomized bronze and brass powders to be annealed at an adequate temperature.
(3) High rate of cooling velocity developes quenched phase structure in alloys, particularly with alloys such as bronze and Kelmet that has a considerable gap between the liquidus and the solidus. Particles atomized with water show fine quenched phase structures, in comparison with the particles atomized with gas.

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Peridinium bipesの栄養細胞の走性を規定する因子について実験的に検討した。使用した株はPeridinium bipes f. occultatumの無菌クローン培養株であり,顕微鏡下で遊泳状態を観察し,遊泳速度や遊泳方向を測定した。光の照射方向を上下に切り替えて遊泳方向を観察した結果,どちらの場合にもP.bipesは上方への遊泳を示したことからP. bipesは負の走地性を有していることが確認された。負の走地性の発現はP.bipes栄養細胞の幾何中心と重心の位置の違いに起因していると推測された。またP.bipesの上方への遊泳速度は主に水温に依存し,光強度に依存していなかったことからP.bipesの鉛直遊泳は主に負の走地性によって引き起こされていると考えられた。走地性による遊泳速度,走光性による遊泳速度および沈降速度を個別に評価し,それに基づいてP.bipes群集の鉛直移動数理モデルを構築したところ,光照射強度0～80.5μmol m^-2 sec^-1の範囲において実際の鉛直移動パターンを再現することが可能であった。一般にPeridinium属は正の走光性を有しており,これが鉛直移動の主因と考えられているが,本結果は明らかに走地性が鉛直移動の主因であることを示しており,今後,Peridinium属の水表面への集積を解析する上で重要な知見であると考えられる。

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科研費報告書収録論文(課題番号：09680320・基盤研究(C)(2)・H9～H10／研究代表者：西関, 隆夫／構造的グラフに対する効率的アルゴリズムの統一的設計法)
The searchlight scheduling problem is to search robbers moving in a simple polygon by searchlights. Each of the searchlights is fixed at a point in the polygon, emits a single ray, and can change the direction of the ray continuously. In this paper, we presenta linear time algorithm to obtain a searchlight scheduling for a given polygon with searchlights on the boundary.

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We edit in this paper several archives on the research and development in the field of microwave circuit technology in Japan, that originated with the invention of Yagi-Uda antenna in 1925, together with generally unknown historical topics in the period from the 1920s up until the end of World War II. As the main subject, we investigate the origin and evolution of the Multiply Split-Anode Magnetron, and clarify that the basic magnetron technology had been established until 1939 under the direction of Yoji Ito in cooperation of expert engineers between the Naval Technical Institute (NTI) and the Nihon Musen Co., while the Cavity Magnetron was invented by Shigeru Nakajima of the Nihon Musen Co. in May 1939, and further that physical theory of the Multiply Split-Anode Cavity Magnetron Oscillation and the design theory of the Cavity Magnetron were established in collaboration between the world-known physicists and the expert engineers at the NTI Shimada Laboratory in the wartime. In addition, we clarify that Sin-itiro Tomonaga presented the Scattering Matrix representation of Microwave Circuits, and others. The development mentioned above was carried out, in strict secrecy, in an unusual wartime situation up until 1945.

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