• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.816-821
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• 2013

This paper proposes the design method of low-cost vector control system for induction motor using the ARM Cortex-M4 microcontroller. This MCU can be used instead of expensive DSP to control the home appliances such as refrigerator, air conditioner, washing machine and so on. This paper explains the major features of Cortex-M4 for motor control and how to realize a vector-controlled inverter using it. The developed system is applied to 3-phase induction motor of 200[W] and experimental results show good performance similar to the system using TMS320F28335 DSP.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.4
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• pp.943-949
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• 2017

Cryptography implementation over lightweight Internet of Things (IoT) device needs to provide an accurate and fast execution for high service availability. However, adversaries can extract the secret information from the lightweight device by analyzing the unique features of computation in the device. In particular, modern ARM Cortex-M3 processors perform the multiplication in different execution timings when the input values are varied. In this paper, we analyze previous multiplication methods over ARM Cortex-M3 and provide optimized techniques to accelerate the performance. The proposed method successfully accelerates the performance by up-to 28.4% than previous works.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.975-985
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• 2004

This study attempts to investigate the developmental alterations of rat cerebral cortex, and the effects of EGEE on the developmental cerebral cortex in the prenatal, postnatal and adults were examined by morphological methods and H-E staining was used for the histological changes. In the case of injection of EGEE, at 14 day of fetal phase, parietal cortex was thickest $(95{\pm}12.7\;{\mu}m)$ but, it was thinner than in the control group $(102{\pm}14.0\;{\mu}m)$ and, occipital cortex $(57{\pm}10.5\;{\mu}m)$ compared with other cortexes was the thinnest in fetal phase. In the suckling phase, each cortex grew thick quickly but, after weanning phase, the growth of the cortex slowed and the thickness of cortex was similar to that of cortex in the adult phase. At 105 day after birth, the parietal cortex was thickest $(934{\pm}21.6\;{\mu}m)$ but, decreased compared with control group $(1113{\pm}19.0\;{\mu}m)$. When EGEE was injected in intraperitoneal of rat, the number of neuroblasts per unit area was largest $(207.7{\pm}11.4/10^{-2}\;mm$ at the mantle layer of parietal cortex at 14 day of fetal phase but, decreased compared with control group $(224.2{\pm}13.8/10^{-2}\;mm$ , and the size was largest $(7.5{\pm}1.3\;{\mu}m)$ at the ependymal cell layer of occipital cortex at 3 day after birth but, decreased compared with control group $(9.0{\pm}1.2\;{\mu}m)$. Simillar to control group, the number of granular cells and pyramidal cells were largest at the II and III layer of parietal cortex, but decreased during developmental phase. The size was largest at the IV and V layer of occipital cortex but it was decreased compared with control group. When EGEE was injected in intraperitoneal of rat, the cerebral cortex from fetal phase to 3 day after birth has differentiated into the 3 layers; ependymal, mantle and marginal layer, but empty cisternaes or vacoules in the cerebral cortexes and the condensed phases of neuroblasts were appeared. From 5 day after birth, it has differentiated into the 4 layers; molecular, external granular, mixed layer of internal granular, external and internal pyramidal cells and multiformal layer but, empty cisternaes or vacoules in the granular and pyramidal cell layers were appeared and the number per unit area of neuron was decreased. In the cerebral cortex of the weaning and adult phases, division of cell layers was not clear and empty cisternae was formed in the cortex with the cells in external granular and pyramidal cell layers, was magnified or condensed around blood vessels of neurons.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.8
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• pp.1133-1138
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• 2018

Lightweight Encryption Algorithm (LEA) is one of the most promising lightweight block cipher algorithm due to its high efficiency and security level. There are many works on the efficient LEA implementation. However, many works missed the secure application services where the IoT platforms perform secure communications between heterogeneous IoT platforms. In order to establish the secure communication channel between them, the encryption should be performed in the on-the-fly method. In this paper, we present the LEA implementation performing the on-the-fly method over the ARM Cortex-M3 processors. The general purpose registers are fully utilized to retain the required variables for the key scheduling and encryption operations and the rotation operation is optimized away by using the barrel-shifter technique. Since the on-the-fly method does not store the round keys, the RAM requirements are minimized. The implementation is evaluated over the ARM Cortex-M3 processor and it only requires 34 cycles/byte.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.317-320
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• 2016

In embedded system, if firmware code is opened by other company, must devise hardware copy prevention. That guard valuable product. Not used security IC, Suggested platform is source code open method that prevent core code and hardware copy. And that open firmware code for other company programmer. Suggest system security platform based on Corex-M3. that consist of IAP(In-application programing) and APP(Applicataion). IAP contain core code and security confirm code. APP is implement by other company developer using core function prototype.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.12-14
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• 2013

임베디드 마이크로프로세서인 ARM Cortex-M3는 기존의 것들과는 달리 짧은 문맥교환을 제공하기 위해 Trap을 이용하여 문맥교환 과정을 일부 하드웨어적으로 처리하는 기능을 제공한다. 일반적으로 Trap (혹은 소프트웨어 인터럽트)은 그 자신만의 오버헤드를 갖고 있는 것으로 알려져 있다. 따라서 본 논문에서는 소프트웨어적으로 문맥교환을 하던 방식에 비해 어느 정도의 성능 향상이 있을지에 대한 정량적인 비교 평가를 수행하여 Cortex-M3를 기반으로 한 임베디드 시스템의 설계에 도움을 주도록 한다.

• Journal of Aerospace System Engineering
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• v.12 no.5
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• pp.48-53
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• 2018

In this study, Real-Time Operating System(RTOS) and 3-D collision avoidance algorithm are implemented to three different Miciro Controller Unit(MCU)s and their performances compared. We selected Microchip Technology's ATmega2560, STM's ARM Cortex-M3 and ARM Cortex-M4, because they are widely used. FreeRTOS, an open-source operating system, was also used. The 3D collision avoidance algorithm consists of the vertical and the horizontal avoidance algorithm, which is implemented using C++. The performances of the MCUs were compared with respect to used memory and calculation time. As a result, Cortex-M4's calculation time was the fastest and ATmega2560 used least memory.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1257-1263
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• 2018

Secure authentication technology is a fundamental building block for secure services for Internet of Things devices. Particularly, the multiplication operation is a core operation of public key cryptography, such as RSA, ECC, and SIDH. However, modern low-power processor, namely ARM Cortex-M3 processor, is not secure enough for practical usages, since it executes the multiplication operation in variable-time depending on the input length. When the execution is performed in variable-time, the attacker can extract the password from the measured timing. In order to resolve this issue, recent work presented constant-time solution for multiplication operation. However, the implementation still missed various speed-optimization techniques. In this paper, we analyze previous multiplication methods over ARM Cortex-M3 and provide optimized implementations to accelerate the speed-performance further. The proposed method successfully accelerates the execution-time by up-to 25.7% than previous works.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.305-305
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• 1994

It has been shown that there are several subtypes of $\kappa$ opioid receptor, We have evaluated the properties of non-${\mu}$, non-$\delta$ binding of 〔$^3$H〕DIP, a nonselective opioid antagonist, in rat cortex membranes. Binding to ${\mu}$ and $\delta$ sites was inhibited by the use of an excess of competing selective agonists (DAMGO, DPDPE) for these sites. (-)Ethylketocyclazocine(EKC) inhibited 〔$^3$H〕DIP binding with Ki. of 70 nM. However, arylacetamides (U69593 and U50488H) gave little inhibition. Also, we have examined the opioid modulation of K$\^$+/(30 mM)-induced histamine release in rat frontal cortex slices labeled with 1-〔$^3$H〕histidine. The 〔$^3$H〕histamine release from cortex slices was inhibited by EKC, a $\kappa$$_1$-and $\kappa$$_2$-agonist, in a concentration-dependent manner(10 to 10,000 nM). The IC$\sub$50/ of EKC was 107 ${\pm}$ 6 nM. However, the $\delta$ receptor selective agonists, DPDPE and deltorphine II, ${\mu}$ receptor agonists, DAMGO and TAPS, $\kappa$$_1$-agonists, U69593 and U50488H, and $\varepsilon$-agonist, ${\beta}$-endorphin, did not inhibit histamine release even in micromoiar dose, indicating that ${\mu}$, $\delta$ or $\kappa$$_1$ receptors are not involved. The concentration-response curve of EKC was shifted to right in the presence of naloxone (300 nM), a ${\mu}$ preferential antagonist, norbinaltorphimine(300 nM), a $\kappa$$_1$ preferential antagonist and bremazocine(1 nM), a $\kappa$$_1$-agonist and $\kappa$$_2$-antagonist. These results suggest that $\kappa$$_2$ opioid receptor regulates histamine release in the frontal cortex of the rat.

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.409-415
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• 2008

Moutan cortex, the root bark of Paeonia suffruticosa Andrews (Paeoniaceae), has pharmacological effects such as anti-inflammatory, antiallergic, analgesic and antioxidant activities. We investigated a methanol extract of Moutan cortex for neuroprotective effects on neurotoxicity induced by amyloid ${\beta}$ protein ($A{\beta}$) (25-35) in cultured rat cortical neurons. Exposure of cultured cortical neurons to $10\;{\mu}M\;A{\beta}$ (25-35) for 24 h induced neuronal apoptotic death. Moutan cortex inhibited $10\;{\mu}M\;A{\beta}$ (25-35)-induced neuronal cell death at 30 and $50\;{\mu}g/m{\ell}$, which was measured by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. Moutan cortex inhibited $10\;{\mu}M\;A{\beta}$ (25-35)-induced elevation of intracellular calcium concentration ($[Ca^{2+}]_i$), and generation of reactive oxygen species (ROS) which were measured by fluorescent dyes. Moutan cortex also inhibited glutamate release into medium induced by $10\;{\mu}M\;A{\beta}$ (25-35), which was measured by HPLC. These results suggest that Moutan cortex prevents $A{\beta}$ (25-35)-induced neuronal cell damage by interfering with the increase of $[Ca^{2+}]_i$, and then inhibiting glutamate release and ROS generation. Moutan cortex may have a therapeutic role in preventing the progression of Alzheimer's disease.