• JSTS:Journal of Semiconductor Technology and Science
• /
• v.6 no.3
• /
• pp.154-161
• /
• 2006

This paper describes the new types of ngative differential resistance (NDR) IC applications which use a monolithic quantum-effect device technology based on the RTD/HBT heterostructure design. As a digital IC, a low-power/high-speed MOBILE (MOnostable-BIstable transition Logic Element)-based D-flip flop IC operating in a non-return-to-zero (NRZ) mode is proposed and developed. The fabricated NRZ MOBILE D-flip flop shows high speed operation up to 34 Gb/s which is the highest speed to our knowledge as a MOBILE NRZ D-flip flop, implemented by the RTD/HBT technology. As an analog IC, a 14.75 GHz RTD/HBT differential-mode voltage-controlled oscillator (VCO) with extremely low power consumption and good phase noise characteristics is designed and fabricated. The VCO shows the low dc power consumption of 0.62 mW and good F.O.M of -185 dBc/Hz. Moreover, a high-speed CML-type multi-functional logic, which operates different logic function such as inverter, NAND, NOR, AND and OR in a circuit, is proposed and designed. The operation of the proposed CML-type multi-functional logic gate is simulated up to 30 Gb/s. These results indicate the potential of the RTD based ICs for high speed digital/analog applications.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.2
• /
• pp.179-184
• /
• 2016

The electrical load testing system developed from this study was designed to control rated-capacity-testing or variable-load-testing in an active and precise manner and save electric energy during testing, and also to convert the saved electric energy through the electrical load testing system to grid line. As for the device under testing, it was designed to be applied to not only transformer, rectifier, voltage regulator, inverter which require grid voltage source but, also applied to electric power, aerogenerator, photovoltaic, hybrid generator, battery, etc. which do not require grid voltage source. The system was designed to return the power consumed during the testing to the grid line by connecting the synchronizing pwm inverter circuit to the grid voltage source, and was also made to enable the being-tested system from disuse of approximately 93.4% energy when compared to the conventional load testing system which has used the passive resistor.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.1
• /
• pp.17-22
• /
• 2017

In this study, we designed the metallic reception part of a patch antenna using the phase field design method. The design object function is formulated with the S-parameter value which represent the return loss so that it is targeted to maximize radiation efficiency at a target frequency. The initial model of a patch antenna was designed via the ordinary theory based approach and its performance was enhanced by changing the structural configuration of the metallic part using the phase field design method combined with the double well potential functions. The final shape was proposed by removing the gray scale area along the structural boundary by employing a cut-off method. The proposed shape shows that the radiation efficiency at target frequency is significantly improved compared with the initial patch shape. The finite element analysis and optimization precess was performed using the commercial package COMSOL and Matlab programming.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.6
• /
• pp.2111-2131
• /
• 2015

Tiered wireless sensor network is a network model of flexibility and robustness, which consists of the traditional resource-limited sensor nodes and the resource-abundant storage nodes. In such architecture, collected data from the sensor nodes are periodically submitted to the nearby storage nodes for archive purpose. When a query is requested, storage nodes also process the query and return qualified data as the result to the base station. The role of the storage nodes leads to an attack prone situation and leaves them more vulnerable in a hostile environment. If any of them is compromised, fake data may be injected into and/or qualified data may be discarded. And the base station would receive incorrect answers incurring malfunction to applications. In this paper, an efficient verifiable top-k query processing scheme called EVTQ is proposed, which is capable of verifying the authentication and completeness of the results. Collected data items with the embedded information of ordering and adjacent relationship through a hashed message authentication coding function, which serves as a validation code, are submitted from the sensor nodes to the storage nodes. Any injected or incomplete data in the returned result from a corresponded storage node is detected by the validation code at the base station. For saving communication cost, two optimized solutions that fuse and compress validation codes are presented. Experiments on communication cost show the proposed method is more efficiency than previous works.

• Clinics in Shoulder and Elbow
• /
• v.5 no.1
• /
• pp.47-54
• /
• 2002

Purpose : We evaluated clinical result of arthroscopic and open Bankart repair in anterior shoulder instability to identify factors iuluencing operative result and prognosis. Materials & Methods . We reviewed 24 patients of anterior shoulder instability treated with arthroscopic Bankart repair in 16 cases and open Bankart repair in 8 cases. Average age was 26 years old and involved in dominant arm in 15 cases. Patients were suffered instability for 3.1 years before operation and mean follow-up was 2 year 9 months ( 1 you 9 months -4year 10 months). Results : Post operative pain was subsided in 2 weeks in arthroscopic surgery and 3 weeks in open surgery. The final range of motion after arthroscopic repair were flekion in 168" , external rotation in 54" , and internal rotation in 79, and after open repair 168" ,49" , and 78 respectively. In arthroscopic surgery,2 cases (13%) were redislocated, and 4 cases(25%) showed mild instability. In open case,1 case (11%) showed mild instability. According to function- al result by Rowe grading scale, satisfactory results were 12case (76%) in arthroscopic repair and 7 cases (88%) in open cases. Conclusions Both arthroscopic or open Bankart could get good results in the treatment of anterior instability of shoulder. In arthroscopic repair, perioperative morbidity was lower than open repair, but it needs careful rehabilitation program to prevent redislocation and to return to sports activity.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.9
• /
• pp.1263-1266
• /
• 2002

The objective of this study was to evaluate the effects of some production factors on commercial production of Etawah Crossbred Goats (ECG) of Inpres Desa Tertinggal member groups (AKIDT) at Krasak, Pandansari, Brajan, and Kragilan villages in Boyolali regency, Central Java, Indonesia. The study was from February to April 2000. Eighty respondents of AKIDT were selected by simple random sampling and the data were analyzed using Cobb Douglas Production Function. The results showed that ECG production simultaneously were highly significant (p<0.01) influenced by amount of feed consumed (kg TDN/year, $x_1$), number of does of ECG (Animal Unit/year, $x_2$), number of kids and does/ barn/year (Animal Unit/year, $x_3$), labor use (man-days/year, $x_4$) and work capital (US$/year, $x_5$) with $R^2= 0.6568$. In addition, ECG production was partially influenced by $x_2$, $x_3$ and $x_5$ (p<0.01) and $x_1$ (p<0.05), but not significant (p>0.05) by $x_4$. Technically, production factors of $x_1$, $x_2$, $x_3$, $x_4$, $x_5$ had reached technique efficiency (0$x_1$, $x_3$, $x_4$, $x_5$ did not showed efficiency (Ep<1) and $x_2$ was not efficient yet.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.4 no.3
• /
• pp.27-42
• /
• 1984

The complexity and expensiveness of water resources projects have made optimum operation and design by computer-based techniques of increasing interest in recent years. Water resources problems in real world need many decisions under numerous constraints. In addition there are nonlinearities in the state and return function. This mathematical and technical troublesome must be overcome so that the optimum operation polices are determined. Then traditional dynamic optimization method encountered two major-cruxes: variable discretization and appearance of constraints. Even several recent methods which based on the Differential Dynamic Programming(DDP) have some difficulties in handling of constraints. This paper has presented New DDP which is applicable to multi-reservoir control. It is intended that the method suggested here is superior to abailable alternatives. This belief is supported by analysis and experiments(New DDT does not suffer course of dimensionality and requires no discretization and is able to handle easily all constraints nonlinearity).

• Women's Health Nursing
• /
• v.1 no.1
• /
• pp.68-80
• /
• 1995

Housewife plays a significant role in maintaining a health family life. If she can not function adequately due to high stress, it will affect quality of life of the household members. It also interferes with the normal process of family development. Futhermore, dysfunctional family will have effects on morale of the servicemen in military. This is a descriptive study. The main purpose of this study is to compare the level and types of stress between a group of military wives and a group of civilian wives and provide a data which can be used to develop a stress management program. Sample consist with 250 military wives and 250 civilian wives residing in metro Seoul area. Data collection was done during October 4, 1994-November 30, 1994. Stress was measured with the instrument developed by the researcher. The cronbach's ${\alpha}$ score of the instrument was .91. The data was analyzed by using SPSS-PC. The results of this study are : 1. The stress score was 47.09 for military wives, 36.56 for civilian wives. The range of score was 0-192. The stress level of military wives was greater than civilian wives. (t=4.80, P<.000) 2. The rank order of stressors of military wives were 1) move 2) residential environment 3) purchase of house 4) holidays. The rank order of stressors of civilian wives were 1) husband late return after work 2) arguments with husband 3) holidays 4) husband's drinking problem. The result shows that the main stressors of military wives are frequent moves, residential environment, uncertainty of the future, unsafe work environment of husband, and the lack of private life which are all associated with the military. Therefore, it is urgently needed to distribute this facts through military journal to understand the characteristic of the stress of military wives, and to develope appropriate health care program to lessen the stress.

• Journal of Korean Neurosurgical Society
• /
• v.39 no.2
• /
• pp.130-135
• /
• 2006

Objective : After ischemic stroke, partial recovery of function frequently occurs and may depend on the plasticity of axonal connections. Here, we examine whether blockade of the Nogo/NogoReceptor[NgR] pathway might enhance axonal sprouting and thereby recovery after focal brain infarction. Methods : Adult male Sprague Dawley rats weighing $250{\sim}350g$ were used. Left middle cerebral artery occlusion[MCAO] was induced with a intraluminal filament. An osmotic mini pump [Alzet 2ML4, Alza Scientific Products, Palo Alto, CA] for the infusion of NgR-Ecto[310]-Fc to block Nogo/NgR pathway was implanted 1 week after cerebral ischemia. Prior to induction of ischemia, all animals received training in the staircase and rotarod test. Two weeks after biotin dextran amine injection, animals were perfused transcardially with PBS, followed by 4% paraformadehyde/PBS solution. Brain and cervical spinal cord were dissected. Eight coronal sections spaced at 1mm intervals throughout the forebrain of each animal with cresyl violet acetate for determination of infarction size. Images of each section were digitized and the infarct area per section was measured with image analysis software. Results : Histological examination at 11 weeks post-MCAO demonstrates reproducible stroke lesions and no significant difference in the size of the stroke between the NgR[310]Ecto-Fc protein treated group and the control group. Behavioral recovery is significantly better and more rapid in the NgR-Ecto[310]-Fe treated group. Blockade of NgR enhances axonal sprouting from the uninjured cerebral cortex and improves the return of motor task performance. Conclusion : Pharmacological interruption of NgR allows a greater degree of axonal plasticity in response this is associated with improved functional recovery of complicated motor tasks.

• The KIPS Transactions:PartC
• /
• v.9C no.4
• /
• pp.453-458
• /
• 2002

Recently, the number of hacking, that use buffer overflow vulnerabilities, are increasing. Although the buffer overflow Problem has been known for a long time, for the following reasons, it continuos to present a serious security threat. There are three defense method of buffer overflow attack. First, allow overwrite but do not allow unauthorized change of control flow. Second, do not allow overwriting at all. Third, allow change of control flow, but prevents execution of injected code. This paper is for allowing overwrites but do not allow unauthorized change of control flow which is the solution of extending compiler. The previous defense method has two defects. First, a program company with overhead because it do much thing before than applying for the method In execution of process. Second, each time function returns, it store return address in reserved memory created by compiler. This cause waste of memory too much. The new proposed method is to extend compiler, by processing after compiling and linking time. To complement these defects, we can reduce things to do in execution time. By processing additional steps after compile/linking time and before execution time. We can reduce overhead.