• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.7
• /
• pp.85-92
• /
• 2010

In this paper, we consider the orthogonal frequency division multiplexing (OFDM) based transmission incoorperating with beam-switching and space-time coding. Specifically, we consider three configurations; (1) the beamforming technique, (2) the spatial diversity technique and (3) their combination and evaluate the performance in wireless personal area network (WPAN) environment. For the beam-forming technique, we consider the beam-switching which is performed at RF front-end with a pre-defined set of beams and for the space-time coding, we consider the Alamauti scheme with antenna selection. For the combined scheme, we divide the antennas used into two group to generate two independent beams and apply the two-antenna Alamauti scheme over the two beams. For these three configurations, performance is evaluated in terms of the SNR gain.

• Journal of Advanced Marine Engineering and Technology
• /
• v.3 no.1
• /
• pp.19-31
• /
• 1979

Recently the adaptive control system, which keeps the control system always optimal by adjusting the control parameters automatically according to the variations of the plant parameters, have become very important in the field of control engineering. The adaptive control systems are usally composed of the plant identification, the decision of the optimal control parameters, and the adjustment of the control parameters. This paper deals with a method of the adaptive control system when PI or PID controller is used in the feed back control system. Its controlled object (the plant) is assumed to be described by the transfer function of $\frac{ke^{-LS}}{1+TS}$ where k, T and L are steady state gain, time constant and pure dead time respectively, and their values are variable in accordance with the change of environmental circumstance. It has been known that a pseudo-random binary signal is quite effective for the measurement of an impulse response of a plant. In adaptive control systems, however, the impulse response itself is not appropriate to determine the control parameters. In this paper, the authors propose a method to estimate directly the parameters of the plant k, T and L by means of the correlation technique using 3 level M-sequence signal as a test signal. The authors also propose a method to determine the optimal parameters of the PI or PID controller in the sense of minimizing the square integral of the control error in the feed back control system, and the values of the optimal parameters are computed numerically for various values of T and L, and the results are examined and compared with those of the conventional methods. Finally the above-mentioned two methods are combined and an algorithm to struct an adaptive control system is suggested. The experiments for the indicial responses by means of both the model of the temperature control system using SCR actuater and the analog simulations have shown good results as expected, and the effectiveness of the proposed method is verified. The M-sequence generator and the time delay circuit, which are manufactured for the experiments, are operated in quite a good condition.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.17
• /
• pp.7129-7135
• /
• 2014

Background: In this study, we aimed to evaluate the growth inhibitory effect of the combination of ethaselen (BBSKE) and low fixed dose of selenite against A549 human non-small cell lung cancer cells in vitro. Materials and Methods: Growth inhibitory effects against A549 cells were determined by SRB assay. Combination index (CI) values were calculated based on Chou-Talalay median-effect analyses. Dose reduction index (DRI) values were applied to calculate dose reduction of selenite. Contents of free thiols and GSH were determined by DTNB assay and intracellular ROS levels by DCFH-DA fluorescence labeling. Results: Compared with BBSKE or selenite single treatment, the combined application of ethaselen and a low fixed dose of selenite shortened the onset time of sodium selenite, reduced $IC_{50}$ values, and increased the maximum inhibition rates, suggesting a possible molecular mechanism of the synergism. Obvious synergistic effects were observed after different times of combination treatment, especially after 24 h. Compared with selenite single treatment, dosage of selenite could be remarkably reduced in combination therapy to gain the same inhibitory effect on cell proliferation. Compared with BBSKE single treatment, the content of free thiols and GSH were significantly reduced and ROS levels greatly elevated in the combination group. For the combination treatment, cell viability increased as greater concentrations of GSH were added. Conclusions: All these results indicate that the combination treatment of BBSKE and selenite showed synergism to inhibit A549 cell proliferation in vitro, and also reduced the selenite dosage to mitigate its toxicity which is very meaningful for combination chemotherapy of lung cancer. The synergism was probably caused by the accelerated exhaustion of intracellular reductive substances, such as free thiols and GSH, which ultimately leads to enhanced oxidative stress and apoptosis.

• Korean journal of food and cookery science
• /
• v.31 no.2
• /
• pp.193-199
• /
• 2015

According to the definition of 'native local food', Jeju has combined its regional specialty products with its own cooking method. It has almost four-hundred kinds, which reflects regional specialty and diversity, yet it is not very well-known. Thus, this present study provides basic research information through the investigation of tourist awareness, intention to consume, drawbacks, development necessity and direction of development of Jeju local foods. The survey was conducted with 295 domestic tourists who had visited Jeju in the last 10 years. In response to a question asked about the consciousness of Jeju local foods, 67.8% of respondents chose average, indicating a relatively high cause for concern. Intention to consume averaged 3.26, which was higher than tourist awareness, having an average of 2.60. Furthermore, local food interest and demographic characteristics of respondents were found to have an influence on tourist awareness and intention to consume. 87.8% of respondents answered above average with respect to the drawbacks of Jeju's local foods and development necessity and direction, with the main drawbacks being lack of PR (43.1%) and high price (39.0%). The priority of most respondents was the quality and taste of the food (50.8%). Based on the results of this study, if tourist awareness can be effectively increased, an escalation in intent to consume will follow, naturally promoting the consumption of Jeju's local foods. Consequentially, for tourism commercialization, the quality and taste of the foods have to be improved in addition to the gain in popularity through efficient PR methods.

• Journal of Periodontal and Implant Science
• /
• v.26 no.1
• /
• pp.80-88
• /
• 1996

The aim of the present investigation was to see the effect of combined use of PDGF BB and IGF -1 on the guided tissue regeneration(GTR) using barrier membrane in the treatment of human furcation involvement. Twelve patients with initially diagnosed as having moderate to advanced adult periodontitis with mandibular class II buccal furcation defects have been wer selected. Initial scaling and root planing has been performed and baseline data consisting of probing depths and attachment levels have been recorded prior to surgical procedures. The GTR procedures using either barrier membrane(control : ePTFE) alone or together with the application of PDGF - BB and IGF -l(experimental : ePTFE+PDGF/IGF) have been done under the routine guidelines. During the surgery, the distance from CEJ either to the bottom of the bone defects(CEJ - BD) or to the bone crest(CEJ-BC) were measured. Horizontal distance to the deepest area in the furcal defects were measured from the reference line connection the most prominent bony walls of the two buccal roots. 6 months following the GTR therapy, all the measurements were made repeatedly. The probing attachment gain of the experimental and the control grous were 2.14mm and l.07mm, respectively with no statically significnant difference. Amont of vertical bone fill in the experimental and the control groups were 2.43mm and 2.29mm, rexpectively. Amonut of horizontal bone fill were 2.86mm in the experimental group and 2.17mm in the control group, respectively. However, there were no significant differences in the amount of bone fill(both vertical and horizontal)between the two groups.

• Journal of Periodontal and Implant Science
• /
• v.48 no.5
• /
• pp.326-333
• /
• 2018

Purpose: The present study investigated the outcomes of a newly-developed, simple, and practical nonsurgical treatment modality suitable for most forms of intrabony defects around failing dental implants using intrasulcular delivery of chlorhexidine solution and minocycline hydrochloride (HCl). Methods: Forty-five dental implants in 20 patients diagnosed with peri-implantitis were included. At baseline and the study endpoint, the probing pocket depth (PPD), clinical attachment level (CAL), and the presence of bleeding on probing (BOP) at 6 sites around each implant were recorded. The radiographic osseous defect morphology at the mesial or distal proximal aspect of each implant was classified as 1) narrow or wide and 2) shallow or deep. For a comparative analysis of bone changes according to the defect morphology, the distance from the implant shoulder to the most coronal bone-to-implant contact point (DIB) at the mesial and distal aspects of each implant was measured at baseline and the endpoint. Patients were scheduled to visit the clinic every 2-4 weeks for intrasulcular irrigation of chlorhexidine and delivery of minocycline HCl. Results: We observed statistically significant decreases in PPD, CAL, and BOP after treatment. At the endpoint, bone levels increased in all defects, regardless of the osseous morphology of the intrabony defect. The mean DIB change in deep defects was significantly greater than that in shallow defects. Although the mean bone gain in narrow defects was greater than in wide defects, the difference was not statistically significant. Conclusions: We propose that significant and sustainable improvements in both clinical and radiographic parameters can be expected when intrabony defects around dental implants are managed through a simple nonsurgical approach involving combined intrasulcular chlorhexidine irrigation and local delivery of minocycline HCl.

• Journal of Yeungnam Medical Science
• /
• v.31 no.1
• /
• pp.61-64
• /
• 2014

Craniopharyngiomas are rare primary intracranial tumors. Despite their benign histological appearance, they are often associated with an unfavorable prognosis. The typical manifestations upon diagnosis are headache, visual impairment, polyuria/polydypsia, growth retardation, disturbance of pubertal development, and significant weight gain. The treatment options include radical surgery or radiotherapy, or a combination of these modalities. Slipped capital femoral epiphysis (SCFE) is the most common adolescent hip disorder. SCFE occurs when the capital femoral epiphysis displaces posteriorly on the femoral neck at the level of the physis. The etiology of SCFE is thought to be multifactorial and may include obesity, growth surges, and less common endocrine disorders. The related endocrine disorders include hypothyroidism, growth hormone supplementation, hypogonadism, and panhypopituitarism. Reported herein is a case of panhypopituitarism caused by craniopharyngioma combined with SCFE.

• Journal of Nutrition and Health
• /
• v.25 no.5
• /
• pp.379-388
• /
• 1992

The present study was designed to evaluate the protective effects of dietary vitamin A or E. and of combination of vitamins A and E on peroxidative deterioration of heart in adriamycin-treated rats. Male Sprague-Dawley rats were assigned to 5 groups according to the dietary supplementation of vitamin A or E Except control rats a dose of 2mg ADR/kg of B. W was injected to these animals intraperitoneally on the same day every week. Adriamycin treatment significantly decreased the weight gain of experimental rats compared with that of control rats, But this decrement was not modified by dietary supplementation of vitamin A or E. Lipid peroxide values of plasma were elevated by ADR treatment. The combined use of ADR and dietary vitamin A or E significantly reduced these values, The interaction between vitamins A and E seemed to be present in the lipid peroxide value of plasma. Catalase and superoxide dismutase(SOD) activities in rat heart were decrased by ADR treatment but glutathione peroxidase(GSH-Px) activity was elevated. Dietary supplmen-tation of vitamin A or E enhanced the heart catalase and SOD activities. except only vitamin A-supplemented group. GSH-Px activity of rat heart tended to be decreased by dietary supple-mentation of vitamin A or E. With ADR treatment polyunsaturated fatty acids such as archido-nic acid(20:4) and docosahexaenoic acid(22:6) were decreased in rat heart. However dietary supplementation of vitamins A and E reduced this decrease. The retinol and tocopherol contents of rat plasma were decreased by ADR treatment. Dietary vitamin A or E influence vitamin A or E content of plasma. The interaction between dietary vitamins A and E was observed in vitamin A or E level of rat plasma.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37C no.11
• /
• pp.1084-1093
• /
• 2012

For large multihop networks, large time synchronization (TS) errors can accumulate with conventional methods, such as TPSN, RBS, and FTSP, since they need a large number of hops to cover the network. In this paper, a method combining Concurrent Cooperative Transmission (CCT) and Semi- Cooperative Spectrum Fusion (SCSF) is proposed to reduce the number of hops to cover the large network. In CCT, cooperating nodes transmit the same digitally encoded message in orthogonal channels simultaneously, so receivers can benefit from array and diversity gains. SCSF is an analog cooperative transmission method where different cooperators transmit correlated information simultaneously. The two methods are combined to create a new distributed method of network TS, called the Cooperative Analog and Digital (CANDI) TS protocol, which promises significantly lower network TS errors in multi-hop networks. CANDI and TPSN are compared in simulation for a line network.

• Korean Journal of Poultry Science
• /
• v.28 no.1
• /
• pp.15-25
• /
• 2001

This experiment was conducted to investigate the effect of feeding two strains of Lactobacillus and virginiamycin on performance, nutrients digestibility and intestinal microflora of broiler chicks(Abor acres$\times$Abor Acres) were randomly allocated into six treatments with four replications for five weeks. Control(no supplement), 0.05% virginiamycin(VM), Lactobacillus crispatus avibro1(LC), Lactobacillus reuteri avibro2(LR), LC+0.05% VM(LC+VM), LR+0.05% VM(LR+VM) were supplemented into basal diets, which contained ME 3,100kcal/kg and CP 22.0, 20.0% for starting and finishing period, respectively. Weight gain, feed intake and feed conversion(FC) were weekly measured. Nutrients digestibility, intestinal microflora and fecal noxious gas were examined at the end of experiment. Weight gains of chicks fed Lactobacillus or VM was significantly higher than control(P〈0.05). Feed intake increased significantly in those supplemental groups(P〈0.05). FC of chicks fed Lactobacillus or VM significantly lower than control(P〈0.05). Degestibility of crude protein, calcium, and phosphorus improved significantly in alone or combined Lactobacillus treatments(P〈0.05). Whereas DM, crude fat and ash digestibility were not statistically different. Feeding Lactobacilli tended to increase the total Lactobacillus spp. in ileum at one and three weeks of age(WOA) and showed significantly higher in cecum than control at 5 WOA. Total yeast were not shown difference at 1 and 3 WOA, but significantly increased at 5 WOA(P〈0.05). The ileal and cecal anaerobes were started to increase from the first WOA. Fecal NH$_3$gas tended to decrease in Lactobacillus treatments compared to that of other treatments.