• 과학기술정책
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• 제16권1호통권157호
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• pp.64-71
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• 2006

Fabrication, falsification, plagiarism (so-called FFP), and other unethical acts damage the trust of public in science and scientists. Scientific communities, governments and research institutions should take the appropriate countermeasures. With the increasing visibility and importance of problem, funding agencies and policy-makers find that they must have a better understanding of this phenomenon, and take steps to prevent it. Science is often said as a borderless activity. In these days, many scientific misconduct cases have been emerging almost simultaneously and worldwide. Thus, the immediate actions should be taken internationally as well as nationally. From these points of view, we, Japan, proposed a new international joint-study at OECD Global Science Forum in February 2006, and the proposal was approved with supports by many countries including Korea. OECD would seek an international perspective to address this worldwide problem, bringing together the representatives of science communities, publishers, funding agencies, and policy makers, and exchanging their experiences.

• Current Optics and Photonics
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• 제3권6호
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• pp.522-530
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• 2019

We present simulation methods to accurately determine the transmission efficiency and far-field patterns (FFPs) of a shallow-etched waveguide grating antenna (WGA) formed on a silicon-on-insulator wafer based on the finite-difference time-domain (FDTD) approach. The directionality and the FFP of a WGA with >1-mm in length can be obtained reliably by simulating a truncated WGA structure using a three-dimensional FDTD method and a full-scale WGA using a two-dimensional FDTD with the effective index method. The developed FDTD methods are applied to the simulation of an optical phased array (OPA) composed of a uniformly spaced WGA array, and the steering-angle dependent transmission efficiency and FFPs are obtained in OPA structures having up to 128-channel WGAs.

• 센서학회지
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• 제29권1호
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• pp.51-58
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• 2020

In this study, a novel method for sweeping automatic linearization of wavelength swept laser is proposed. Through the test performed on the implemented laser, the linear sweeping is held up well with a 97% decrease in nonlinearity, and 60 nm sweeping range, 1 kHz sweeping frequency, and 8.8 mW average optical power were obtained. The proposed method uses fiber Bragg grating array, optical-electronic conversion circuit, FPGA embedded module, and a LabVIEW program to generate new compensated wave patterns which were applied to the fiber Fabry-Perot tunable filter. Linear sweeping can reduce the cumbersome and time-consuming recalibration process required for nonlinear sweeping. Additionally, the proposed method provides more accurate measurement results for the structure safety monitoring system.

• 한국항공운항학회지
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• 제14권4호
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• pp.74-86
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• 2006

As competition among airliners is getting sharper, promotion mix has been more important for new customers as well as old customers. In this research, how the systems for giving benefits for frequent flying customers are organized and the effects of the systems are analyzed. also, the effects of providing information by internet and issuing bonus card are investigated. As a research method, we inquired into questionnaire, and multi-regression test and ANOVA analysis are conducted. The customers who fly more frequent and have more desire to utilize milage cooperation system among airliners show more loyalty to the systems. Also, cooperation system among different industries is turned out to be effective from the marketing point of view. Also, the result of the test of internet-based system showed effective.

• 전자공학회논문지D
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• 제35D권3호
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• pp.70-81
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• 1998

Fiber-Fabry-Perot (FFP) tunable filters, the essential component of WDM transmission, were designed, fabricated and characterized. Multi-layered thin film mirrors that consists of an optical collimater's corss section as a substrate and TiO$_{2}$SiO$_{2}$ alternating multi-layered films as a filter wer designed by means of the transfer matrix method. Fabricated mirrors showed the high reflectivity over around 98% as expected. After fabricating the tuneable filters using PZT, we measured FSR, FWHM, finesse , crosstalk and insertion loss, confirming that the built devices satisfied the optical filter's specifications required in the SEDM transmission systems.

• Journal of the Optical Society of Korea
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• 제19권2호
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• pp.154-158
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• 2015

We experimentally demonstrated a novel wavelength-swept laser using a cascaded Raman gain around 1310 nm. A 1064/1310 wavelength division multiplexing (WDM) coupler and coupled fiber Bragg gratings mirrors at 1064, 1117, 1175, 1240 nm are effectively used to increase the power efficiency in a laser ring cavity with highly non-linear fiber (HNLF) of 2 km. Linear wavelength sweeping is demonstrated with the 100 Hz triangular driving signal to fiber Fabry-Perot tunable filter (FFP-TF) around the 1310 nm region. The measured sweeping range and output power were 27 nm and 2.1 mW, respectively, which are suitable for optical coherence tomography (OCT) imaging.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.103-106
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• 2006

Semiconductor laser diode has a reflective facet in a both-ends side fundamentally. Laser performance for improving, Anti-Reflection and High-reflection coating on the facet of semiconductor laser diode. To prevent internal feedback from both facets for realizing superluminescent diode and reducing the reflection-induced intensity noise of laser diode, it's key techniques are AR/HR coatings. In the study AR coating film were manufactured by Ion-Assisted Deposition(IAD) system. Then manufactured coating film measurement electrical properties(L-I-V, Se, Resistor) and Optical properties (wavelength FFP)

• 센서학회지
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• 제29권6호
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• pp.412-419
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• 2020

In this study, a PID control method for sweeping automatic linearization of a wavelength swept laser is proposed. First, the closedloop transfer function embodying the PID control is derived. Through the simulation of the function, K_p = 0.022, K_i = 0.008, K_d = 0.002 were obtained as the best PID coefficients for fast linear sweeping. The performance test using the PID coefficients showed that linear sweeping was held up well with a 98.7% decrement in nonlinearity after the 10th feedback, and 45 nm sweeping range, 1 kHz sweeping frequency, and 8.8 mW average optical power were obtained. The equipment consists of a fiber Bragg grating array, an optical-electronic conversion circuit, and a LabVIEW FPGA program. Every 5s, automatic feedback and PID control generate a new compensated waveform and produce a better linear sweeping than before. Compared with nonlinear sweeping, linear sweeping can reduce the cumbersome and time-consuming recalibration processes and produce more accurate measurement results.

• Journal of Trauma and Injury
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• 제33권2호
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• pp.74-80
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• 2020

Purpose: This study was conducted to investigate whether rapid and efficient administration of blood products was achieved and whether clinical outcomes were improved by applying a massive transfusion protocol (MTP). Methods: From January 2016 to September 2019, the medical records of trauma patients who received at least 10 units of packed red blood cells (PRBC) at Pusan National University Hospital (level I trauma center) were retrospectively reviewed. The patients treated from January 2016 to January 2018 were designated as the non-MTP group, and those treated from February 2018 to September 2019 were designated as the MTP group. Results: During the study period, 370 patients received massive transfusions. The non-MTP and MTP groups comprised 84 and 55 patients, respectively. No significant between-group differences were found in the units of PRBC (23.2 vs. 25.3, respectively; p=0.46), fresh frozen plasma (FFP) (21.1 vs. 24.4, respectively; p=0.40), and platelets (PLT) (15.4 vs. 17.0, respectively; p=0.54) administered in the first 24 hours. No statistically significant differences between the non-MTP and MTP groups were found in the FFP-to-PRBC ratio (0.9 vs. 0.94, respectively; p=0.44) and or the PLT-to-PRBC ratio (0.72 vs. 0.72, respectively; p=0.21). However, the total number of cryoprecipitate units was significantly higher in the MTP group than in the non-MTP group (7.4 vs. 15.3 units, respectively; p=0.003) and the ratio of cryoprecipitate to PRBC in the MTP group was significantly higher than in the non-MTP group (0.31 vs. 0.62, respectively; p=0.021). The time to transfusion was significantly reduced after MTP implementation (41.0 vs. 14.9 minutes, respectively; p=0.003). Conclusions: Although no significant differences were found in the clinical outcomes of patients who had undergone severe trauma, rapid and balanced transfusion was achieved after implementing the MTP.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권1호
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• pp.78-82
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• 2001

Background : The coronal incision is versatile surgical approach to upper and middle region of the facial skeletal including the zygomatic arch. The advantages of coronal approach are minimal injury of facial tissue including facial nerve and satisfactory cosmetic result by hidden scar at hair. But wide exposure of scalp, its disadvantages are operation time and massive blood loss. Methods : Thirty patients undergoing elective surgery were divided 3 groups. Group I used only coronal approach, group II used coronal with subciliary approach and group III used coronal with subciliary and intraoral approach. And then retrospected of the preoperative, postoperative red blood cell count, hemoglobin(Hb), hematocrit, transfused red blood cell units and platelet cell units, and the amount of infused crystalloids and colloids, and postoperative hemovac count was estimated. Results: 1. Red blood cell count were decreased in all groups at immediated postoperation and decreased in all group of postoperative first day and decreased in group I, II but increased group III of postoperative third day. 2. Hemoglobin and hematocrit were decreased in all group at immediated postoperation and decreased in all group of postoperative first day and decreased in group I, II., but increased group III postoperative third day. 3. Platelet was decreased in all group at immediated postoperation, and decreased in group II, III but increased in group I of postoperative first day and decreased in group I but increased group II, III of postoperative third day. 4. Mean postoperative hemovac mean drainage group I of first day is $48.63{\pm}21.12ml$ and second day is $23.92{\pm}19.53ml$ and third day is $7.82{\pm}5.32ml$ and group II of first day $60.45{\pm}22.65ml$ and second day is $22.14{\pm}13.21ml$ and third day is $7.32{\pm}6.25ml$. III group of first day $58.16{\pm}10.13ml$ and second day is $21.27{\pm}11.72ml$ and third day is $7.13{\pm}4.90ml$. 5. Infusion of group I is mean PRC $1.08{\pm}0.91$ pint, FFP $1.03{\pm}0.75$ pint, crystalloid $2562.23{\pm}1345.53ml$ and group II is mean PRC $1.05{\pm}0.89$ pint, FFP $1.71{\pm}0.78$, crystalloid $2650.47{\pm}1096.36ml$ and group III is mean PRC $1.79{\pm}1.45$ pint, crystalloid $3295.43{\pm}1472.432ml$.