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Static random access memories (SRAMs) are prone to a single-event upset (SEU), also known as soft errors, due to transient noise caused by a single strike of radiation. Beam testing has been extensively used to measure the SEU cross section of SRAMs as a function of the linear energy transfer (LET) of charged particle radiation. The evolution of the cross section as a function of LET is called the cross section curve, which plays a vital role in upset rate analysis for hardness assurance. Various analytical models have been developed to describe SRAM SEU cross section curves, and they have proven to be useful in reducing the cost of beam testing as well as revealing the physics behind test results. However, they involve arbitrary parameters, which make it challenging to predict cross section curves without any beam results. Moreover, the current method of analyzing cross section curves or the LET dependence of cross sections relies on a model different from that is used in the analysis of power-supply-voltage dependence, which is becoming increasingly important because of the demand for low-power operation. To overcome these problems, this article proposes a unified equation that describes both LET and the power-supply-voltage dependence of SRAM SEU cross sections. It comprises only parameters that are physically clear and familiar to SEU researchers. As well as giving possible constraints, comparisons with data from the literature suggest it can be applied to SRAMs fabricated in bulk and silicon-on-insulator (SOI) processes across generations from the early 1000-nm-scale to the current 10-nm-scale technology nodes.

Static random access memories (SRAMs) are prone to a single-event upset (SEU), also known as soft errors, due to transient noise caused by a single strike of radiation. Beam testing has been extensively used to measure the SEU cross section of SRAMs as a function of the linear energy transfer (LET) of charged particle radiation. The evolution of the cross section as a function of LET is called the cross section curve, which plays a vital role in upset rate analysis for hardness assurance. Various analytical models have been developed to describe SRAM SEU cross-section curves, and they have proven to be useful in reducing the cost of beam testing as well as revealing the physics behind test results. However, they involve arbitrary parameters, which make it challenging to predict cross-section curves without any beam results. Moreover, the current method of analyzing cross-section curves or the LET dependence of cross sections relies on a model different from that is used in the analysis of power-supply-voltage dependence, which is becoming increasingly important because of the demand for low-power operation. To overcome these problems, this paper proposes a unified equation that describes both LET and the power-supply-voltage dependence of SRAM SEU cross sections. It comprises only parameters that are physically clear and familiar to SEU researchers. As well as giving possible constraints, comparisons with data from the literature suggest it can be applied to SRAMs fabricated in bulk and silicon-on-insulator (SOI) processes across generations from the early 1000-nm-scale to the current 10-nm-scale technology nodes.

The effects of buried-well potential perturbation under the buried-oxide (BOX) layer are studied in both a heavy-ion single event upset (SEU) test and a high-energy proton-SEU test of a silicon-on-insulator (SOI) dual interlocked storage cell (DICE)-based flip-flop. Their dependence on incident angle and back bias is discussed. We fabricated both DICE-based flip-flop and conventional flip-flop, which are designed as 80 000-stage shift-register chains. In a heavy-ion test, a considerable number of SEUs were observed at back bias exceeding 2.4 V, and a ten-times larger SEU-cross section was finally recorded at back bias of 3.0 V compared with the total active area of a DICE-based flip-flop cell. This marks the first case where DICE topology was found to be broken by buried-well potential perturbation on an SOI DICE-based flip-flop. In a proton test, one error was observed at back bias of 2.0 V. The SEU rate in the Van Allen belt at an altitude of 2300 km and an inclination of 90° was estimated as being once every 5 years.

形態: カラー図版あり, Physical characteristics: Original contains color illustrations, Accepted: 2019-06-11, 資料番号: PA2010016000

We report the results of single-event effects test using heavy ions and total ionizing dose test using γ-ray in JAXA qualified super-junction power MOSFETs manufactured by Fuji electric company and COTS super- junction power MOSFETs.

Redundant pairs of SOI transistors have been utilized as a Radiation Hardening-By-Design technique. Their applicability was subsequently extended for analog circuits, such as current mirror circuits, and successfully demonstrated with a phase-locked loop circuit.

It was demonstrated that several kinds of permanent damage were introduced by heavy ions in AlGaN/GaN HEMTs similar to SiC devices. A new mode of damage attributable to the transistor structure was also identified in addition to the damage observed similarly in SiC devices.

はじめに：透析性脊椎症には破壊性脊椎症（DSA）や脊椎アミロイド沈着，軸椎歯突起病変があるが，当科での軸椎歯突起病変の手術例について検討した．方法：対象は当科で手術を行った軸椎歯突起病変の8例（男性5例，女性3例）．手術時年齢は47～59歳（平均54.1歳）で，そのうち環軸椎亜脱臼を認めたのが6例，歯突起偽腫瘍を認めたのが2例であった．環軸椎亜脱臼例には後頭頚椎固定術を，歯突起偽腫瘍例には後弓切除術のみを施行した．結果：透析歴は25～30年（平均27.9年）と全例が極めて長期の透析症例であったが，手術前後でJOA scoreは良好に改善し，周術期の合併症も認めなかった．考察：透析患者の軸椎歯突起病変では，手術時に全例25年以上と極めて長期の透析歴を有していたが，周術期合併症もなく良好な術後経過を得られている．

The new SET characterization technique for 0.15 mum Fully Depleted CMOS/SOI digital circuitries was investigated using SPICE and TCAD simulations. The SPICE simulation with a switch can readily reproduce the corresponding SET voltage response for a certain LET. This technique is valid as an alternative in all load and complementary transistor conditions, irrespective of the presence of a plateau region in the SET current waveform generated in a struck transistor.

We describe proton induced bulk damage observed in 90 nm process SDRAM. The degradation of the data retention ability was evaluated. The effect due to the difference of process technology and memory cell structure was discussed. The result indicates that the value of the capacitance of the storage capacitor and the volume of the depletion region are key parameters concerning the failures caused by bulk damage.

We designed logic cells hardened for SEUs/SETs using hardness-by-design (HBD) methodology with OKI's 0.15 mum Fully Depleted CMOS/SOI commercial process and these cells were evaluated with sample devices. Our previous work demonstrated that SET-free inverters could be successfully applied as SEU-immune latches. In this work, the logic cells were optimized for SEU/SET immunity up to an LET of 64 MeV/(mg/cm 2), demonstrating that the process was suitable for space applications with a little penalty

We designed logic cells hardened for single-event upsets/single-event transients (SEUs/SETs) using hardness-by-design (HBD) methodology on OKI's 0.15 /spl mu/m fully depleted complementary metal-oxide-semiconductor/silicon-on-insulator (CMOS/SOI) commercial process and evaluated the sample devices. Our previous work demonstrates that SET-free inverters can be successfully applied as SEU-immune latches. In this paper, the native latches are redesigned using SET-free inverters not only for the inverter loop but also for several types of clock gates (L-SETfree-LoopCK, L-SETfree-LoopCK-SmallArea, and L-SETfree-LoopCK-AddTr.). In addition, the native combinational logic cells are redesigned using SET-free inverters as SET-free NAND and SET-free NOR . Excellent SEU/SET hardness of the HBD latches were achieved up to LET of 64 MeV/(mg/cm/sup 2/).

We evaluated single-event effects (SEEs) in test circuits fabricated at OKI with their 0.15 /spl mu/m Fully Depleted CMOS/SOI commercial process. The sample devices were designed with hardness-by design (HBD) methodology. The results are discussed for an effective hardening design associated with SEEs.

We evaluated SEEs in sample circuits fabricated at TSMC and Fujitsu with their 0.18 /spl mu/m CMOS commercial processes. The samples were designed with hardness-by-design methodology. The results were discussed for effective hardening design associated with SEEs.

A new failure mode that is attributable to the bulk damage caused by single protons has been reported in 256-Mbit SDRAMs. The refresh rate required to retain memorized data was measured as a typical parameter to detect the effect. We performed the proton irradiation test and discussed results regarding the influence of this failure.

It has been demonstrated that there are substantial differences between the form of defects introduced by electrons and those introduced by protons and heavy ions in Si charge coupled devices (CCDs). The consistency of the relationship between the displacement damage factor and nonionizing energy loss (NIEL) for electrons, protons, and heavy ions was clearly explained by the differences.

Calcifications are commonly found at shoulder joints. In this paper, we discuss two cases of calcifications at the hip joints which were comparatively unusual and caused acute symptoms.Case 1 was a 53-year-old woman. She noticed pain in her right hip joint at night. There was no redness or local heat. Tenderness and swelling were observed at the front of the right hip joint. Slight increase of CRP and leukocytes were noticed. Roentgen examination showed calcification measuring 2cm in diameter around the right hip joint. MRI examination showed calcifications in the tendon of the rectus femoris muscle. Calcifications broke down a week after onset and more or less disappeared a month later.Case 2 was a 41-year-old man with pain in his right hip. From the next day, he found it difficult to walk due to the pain. Tenderness was noticed around the right greater trochanter. Significant increases in CRP and a number of leukocytes were found. There was no local redness and no general fever. Radiographic examination showed calcifications around the right greater trochanter. Gluteus maximus and gluteus minimus were enhanced on MRI. The symptoms disappeared ten days later, and the shadow disappeared on radiograph a month later.

We report a rare case of rapidly progressive necrotizing fascitis of a lower limb, whose life could be saved with an amputation at the thigh. A 38-year old man consulted a near-by hospital with swelling and pain of his right crus without traumatic history, and was followed up conservatively. But got worse rapidly, and fasciotomy was performed with the diagnosis of compartement syndrome of crus. The next day, necrosis of the fascia was found, and swelling and redness had advanced to his right thigh. Suspecting necrotizing fascitis, deburidement of the necrotic fascia was performed. Soon after the operation, his consciousness level and blood pressure became low, upon which the patient was transferred to our hospital. On the same day we performed an amptation at his right thigh.After this operation, despite kidney failure and redness which had advanced to the hypochondrial level, chemotherapy, following the operation proved effective and has general condition showed improvement. About one month after the amptation we performed stump plasty and closed the wound.

New types of multiple-bit upset (MBU) modes have been identified in high density DRAMs (16 Mbit and 64 Mbit). The identification of the mechanisms responsible for the new modes is based on detailed physical bit-map analysis.

We report a case with rapidly destrucitve chages of the hip joint with a difficulty in diagnose. The patient is 52 year-old male. His chief complaint is left coxalgia. He had felt the severe coxalgia suddenly and severe gait disturbance appeared, he visited a near hospital and admitted for further examination. But no remarkable changes was found in X-ray. Therefore, followed up with a conservative therapy. One month later, high fever (about 39 degrees), liver and kidney dysfunctions appered and once became unconcious cious. Since then, his coxalgia was getting more and more severe. 2 more months later, he consulted anothre doctor and was diagnosed avascular necrosis of the femoral head with severe destruction in X-ray figure. But, because of low function of his liver and kidney, operation could not be done. He admitted our hospital for examination 9 months later. With CT and MRI, we found a huge cyst extending from left groin to buttock, which contains a retention of much effusion in its cavity. The cyst occupied with yellow debris and brown colored granulation was confirmed at the open biopsy. And Anaerobic bacteria and Staphylococcus aureus were positive in the culture of the open biopsy. So we diagnoted shronic suppurative coxitis at last.

To know the changing of the hand in patients with early-staged Rheumatoid arthritis (RA), we performed fat-suppressed Gd-enhanced MR imaging and investigated the usefulness. We studied 10 patients (2 men, 8 women; age range 37-73 years) with RA which fullfilled the American College of Rheumatology criteria. MR imaging was performed within one year after the onset of RA All patients showed Gd-enhanced T1 weighted spin echo with fat suppression. A high signal intensity of synovia in the intercarpal bone joint, MP or PIP joint was obtained in all 10 patients. The flexor tendon sheaths were also enhanced in 6 ont of 10 patients. These findings show that the inflammation of the synovia and flexor tendon sheath were the main focus in the hands of early stage RA patients and that fat-suppressed MR imaging was useful to describe these changes.

In 1986, Bigliani studied the relationship between the shape of the acromion and rotator cufftears. He reported that a higher incidence of rotator cuff tears results in a hooked type acromion. The aim of this study is to investigate the relationship between the morphology of the acromion obtained at surgery with that of the pre-operative MR image and Scapular Y view.56 patients with an average age of 56 years were operated on, pre-operating MR imaging was carried out in 47 cases and Scapular Y view was in 43 cases. The acromion was obtained at surgery by lateral acromioplasty. The acromion was sliced into a thickness of 100μ and it was classified as flat (type 1), smoothly curved (type 2), or hooked (type 3) according to Bigliani's classification. Scapular Y view was taken with a X-ray fluoroscopy so that the undersurface of the acromion could be observed and classified into three groups. The acrominal shape of MRI imaging was classified from the sagital oblique gradient echo images, and Scapular Y view were obtained and classified into the same classification.Specimens type 1, type 2 and type 3 were 19.6%, 48.2% and 32.1% respectively. The accurancy of MRI image and Scapular Y view were 51.1% and 37.2%. In this study, no higher incidence of rotator cufftears was found in hooked type acromion, but there was a difference between the acrominal type in MRI imaging, Scapular Y view and that of specimens.

We reported a case of radial head dislocation, the pathology of which we could determine by MRI images.A 12 year old boy, who had had no traumatic history of his right elbow, was introduced to our hospital due to the flexion disturbance of his right elbow. Pre-operative MRI images showed the soft tissue at radio-capittelar joint. So we estimated it annular ligament.In the annular ligament existing in the radio-capittelar joint which was seen on MRI images. We performed only reduction of the annular ligament and radial head without reconstruction of the ligament.MRI was useful in understanding the pathology of this case, and it may be a dislocation caused by “pulled elbow” during his childhood.

This paper describes the Single Event Effect test result on the Radiation Hardness-By-Design SRAM for 0.15µm Fully Depleted CMOS/SOI-ASIC fabricated by a commercial foundry. Sufficient immunity was demonstrated for the SEU/SET required for space applications.

In recent years, due to the demand for increased integration and device scaling, integrated circuits (ICs) have been designed with the design rule less than 100 nm. In these ICs, single-event upsets (SEUs) and single-event transients (SETs) are serious problems because their supply voltage and the threshold voltage of the transistors are decreased. A DICE memory cell is said to have excellent tolerance against SEUs. A DICE-based flip-flop with a SET pulse discriminator circuit on a 90-nm bulk CMOS was designed and fabricated. Its improved performance was demonstrated through radiation testing and discussion was made in comparison with a TMR. SEU sensitivity for the angled irradiation was measured and discussed in this study. The test of edge-on irradiation was performed for the first time. The importance of the angled irradiation for the memory cells that have redundant memory nodes was demonstrated.

This paper describes Total Ionizing Dose and Single Event Effects test results of a Radiation Hardness-By-Design Library for 0.15μm Fully Depleted CMOS/SOI-ASIC at a commercial foundry. Reasonable data was obtained to improve the library.

According to the CMOS device on SOI substrate (SOI CMOS device), we investigate the influence of holes accumulated in buried oxide film (BOX) under the radiation environment by monitoring leakage current with back bias. We confirmed that the leakage current has the colleration to total ionizing dose (TID). SOI CMOS assumed to be not good on TID, compared to bulk. But, we confirmed the tolerance to TID in SOI CMOS was improved from 200 to 3000 Gy(Si) with the process optimization, which is better than bulk CMOS.

We carried out a pathological examination of the inferior surface of the acromion in cases with rotator cuff tears to clarify the pathogenesis of such tears. Fifteen male patients with an average age of 53.3 years were operated on and all but one had a history of trauma. The lateral portion of the acromion was resected to prevent impingement syndrome and was examined microscopically to determine the degree of degeneration of the inferior surface.Degeneration of the outer part of the resected acromion was more severe than that of the inner part. The degree of degenertion was siginificantly related with an increase in age but had no relation with the period after trauma or with the size of cuff ruphad no relation with the period after trauma or with the size of cuff rupture.These results suggested that degeneration of the inferior surface of the acromion among middle aged men may arise with aging, or the cuff dysfunction may pre-exsist before any symptoms become apparent.

A conceptual study was undertaken on earth observation missions for a satellite within the Sun-Synchronous and Medium Earth Orbit (SS-MEO). Our mission study of a MEO Satellite was performed as pioneering research into a newly utilized earth orbit that exists between the Low Earth Orbit (LEO) and the Geostationary Earth Orbit (GEO). One of the advantages of the MEO is that it delivers a wider field of view (FOV), which permits more frequent observations that are more easily obtained, in comparison with the LEO. Another advantage is that the performance demands for sensors are moderate, relative to those for the GEO. This conceptual study of earth observation missions is considered for the baseline (4184 km) orbits, focusing on optical sensors. We summarize the needs of each assumed user (products, observational frequency, and spatial resolution) related to four missions (agricultural, forest, ocean, and air pollution observations). Agricultural observation is expected to need a spatial resolution of 10 m and an observational frequency of a few times a week. As a result, required optical sensor is that with an aperture diameter of 30 cm, an f-number of 11, and a signal-to-noise ratio (S/N) of 20. It is thought that the optical sensor for the agricultural observation would be larger in comparison with the previous optical sensors used within the LEO, because the S/N and FOV are smaller. However, it was found there is a challenge to be met in terms of a compatibility with the f-number and FOV. This paper shows the results of this conceptual study and the issues raised relating to mission sensors for earth observation missions in the MEO., 資料番号: PA1410077000

The Medium Earth Orbit (MEO) offers a greater width of satellite view than the Low Earth Orbit, and a greater roximity to the Earth’s surface than the Geostationary Earth Orbit. Global positioning systems and ionospheric sounding satellites have already operated in this orbit, and the MEO will appeal to satellite missions undertaking Earth observations,communications, positioning, and scientific explorations. The Sun-Synchronous Medium Earth Orbits (SS-MEOs) used in this study enable clear and daily observations of the Earth’s surface. However, problems such as severe radiation from the Van Allen radiation belt, and the inefficiency to launch a satellite in a southwest direction, need to be resolved. This paper presents the results of early studies on SS-MEO utilization: orbital characteristics and environments, candidates for Earthobservation missions, and the feasibility of the development and launch of a satellite for operation within this orbit., 資料番号: PA1410079000

The well-being of clinical practice, medical research, and medical education is about to be destroyed by the largest-ever example of misguided government in modern Japan: the structural reforms proposed by the Koizumi cabinet. Negative trends are becoming increasingly obvious, including an increase of medical errors, substantial reduction of medical quality, deterioration of the quality of medical students, and increased data fabrication in medical research. One of the root causes of these trends is that value judgments tend to be made on the basis of a results-oriented approach (rapidly introduced market fundamentalism-based U.S.-style systems) in all aspects of society, including medicine and clinical practice. I believe this has led to the collapse of the social climate that has always nurtured Japan’s essential humanity, such as humane sympathy based on the traditional “bushido” spirit, sincerity, and true professionalism, of which the Japanese people and society had long been proud. People-friendly medical practice is about to disappear; with health-care systems based on a dubious, contract-like facade to evade responsibility as well as for-profit health care corporations prevailing. Am I the only one worrying that even medical research, traditionally aimed at providing hope for patients, may finally decline? What will be the effects of the new postgraduate clinical training systems introduced in 2004 on clinical practice and medicine in Japan, specifically the status of basic medical research? Medical internship and medical research systems introduced to Japan after World War II had a critical defect: Under these systems, there was a tendency even in clinical medicine for academic research activities to be overvalued while clinical practice and educational activities were undervalued. The attitude of “giving top priority to research and writing” even in clinical medicine may lead to serious problems. Although today’s deterioration in clinical practice has not wholly resulted from the former training systems, it is noteworthy that the new training systems have led to certain improvements, such as (1) financial assurance for medical interns, (2) freedom when choosing training hospitals, and (3) enhancement of the quality of training programs. According to the results of a survey conducted this year by the Ministry of Health, Labour, and Welfare, however, 92% of medical interns intend to obtain specialist qualifications under the new system, whereas those who intend to obtain a Ph.D. degree account for only 35%. In the field of orthopedics, for example, most young surgeons care only about improving their techniques and try to master them; thus, there is a risk of their aiming to become mere “medical carpenters.” Furthermore, new training systems, which emphasize the specialist system, could finally eliminate the Ph.D. and postgraduate education systems, which together have been supporting basic medical research in Japan. These systems have provided the basis for an ideal process whereby clinicians solve various problems arising from clinical practice by applying methods of basic medical research and then feeding back the results to clinical practice. The introduction of new training systems actually means “worsening,” not “reforming,” medical research in Japan because this is likely to prevent the advancement of medical research. In other words, the new systems are at high risk of becoming a “major pitfall” that will lead to the collapse of the basic medical research system in Japan. The introduction of new postgraduate clinical training systems will certainly reduce the chances for clinicians to develop research-oriented and scientific minds. It will also deprive them of opportunities to develop an interest and participate in basic medical research. I am confident that I am not the only one worrying that this may be a great obstacle to nurturing orthopedic clinicians with adequate problem-solving skills, who represent the type of clinician patients need and respect. An appropriate intervention in this situation would be to establish a system requiring would-be specialists to work as research fellows for a certain period to maintain and advance basic medical research in orthopedics in Japan.