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본 연구는 지속가능한 도시혁신생태계의 구축방법으로, 대구에서 진행되고 있는 리빙랩 기반의 스마트시티 서비스에 활용되고 있는 도시혁신플랫폼을 소개한다. 도시혁신플랫폼의 구성내용과 작동원리, 운영철학을 소개하고, 지속가능한 리빙랩 기반 스마트시티 서비스를 모델링하는 과정을 탐색한다. 대구 도시혁신플랫폼은 상부구조와 하부구조로 구성되어 있다. 상부구조는 스마트시티즌과 시민과학자를 도시 내에 확산하고, 하부구조는 구체적인 장소와 맥락에서 도시문제를 해결하기 위해 훈련된 시민과학자들과 이해관계자가 공동창조하는 다양한 리빙랩으로 구성되어 있다. 리빙랩기반 스마트시티서비스를 활용한 도시혁신플랫폼은 자발적인 시민 커뮤니티와 도시의 숙의성을 촉진하며, 창조적 개인과 공간을 다층적으로 연결 확장하여 도시의 혁신밀도를 높인다.

This letter presents a fully integrated two-stage monolithic microwave integrated circuit (MMIC) power amplifier (PA) with a 1:1 transformer balun in Taiwan Semiconductor Manufacturing Company (TSMC) 180-nm CMOS process. To optimize the performance of PA, an on-chip 1:1 turn spiral transformer balun (STB) was used with a high supply power through the cascode topology. The proposed PA achieved a 40–43-dB gain and a saturation power ( $P_{\mathrm {sat}}$ ) of 29.9–30.3 dBm with a 40%–45% of power-added efficiency (PAE) in the frequency range of 820–1000 MHz. Using the antiphase biasing technique, the PA achieves a linear output power of 25 dBm with 29.5% PAE in 20-MHz spacing two-tone measurement, which satisfies IMD3 $3.3\times 0.86\,\,{\mathrm {mm}}^{2}$ .

This paper proposes a wideband reflection-type phase shifter (RTPS) suitable for 5G applications at mm-wave. In this phase shifter, a quadrature hybrid coupler was used as a transformer-based quadrature hybrid for broadband operation. In addition, the reflection term is composed of a varactor, an inductor, and a transmission line. The RTPS is cascaded to satisfy the phase shift range of 180°. The RTPS was fabricated in 1V 1-poly 9-metal 65-nm CMOS technology. The experimental results show that the constructed RTPS has a phase-shifting range of 184.9°, an insertion loss of 9.1 dB, a return loss of 8 dB, and an insertion loss variation of ±2.5 dB at an operating frequency of 25–43 GHz.

In this article, a new design of a Wilkinson power divider is presented that offers substantially improved amplitude and reduced size characteristics over a broad frequency range compared to a conventional Wilkinson power divider. The improvement in bandwidth is obtained by reducing inductance and number of lumped components in even mode. The analytical design equations for this proposed power divider are obtained using even and odd mode analysis. This power divider with a compact size is fabricated using 65 nm 1P9M CMOS technology. The measurement results show an operation bandwidth 26–40 GHz with 15 dB input, output return loss, and 0.7 dB insertion loss. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:128–131, 2017

In this letter, a 2.4-GHz double-balanced passive mixer is presented which offers high conversion gain. The improvement of the local oscillator (LO) and RF input voltage is obtained as a ${Q}$ -factor by the LC resonance of the $\pi $ -type inductor-capacitor-inductor matching network. This passive mixer with a high conversion gain is fabricated using 90-nm-1P5M CMOS technology. The mixer down converts a 2.4-GHz RF frequency to an intermediate frequency of 10 MHz. The measurement results show a 6.5-dB voltage conversion gain, a −6 dBm 1-dB compression point when LO power is −5 dBm and zero dc power consumption.

In this paper, we calculate monostatic RCS(Radar Cross Section) and bistatic RCS for improving the Performance of the skin tracking of KSLV-II and the results were compared. EM(Electromagnetic) simulator was used for numerical analysis. For the two paths(L, S), after the vehicle was launched, RCS was calculated for region from 280 to 400 seconds. In the case of using the bistatic radar system, when the vehicle was launched to the L path, tracking performance was better when we receive RCS in Jeju than in Goheung. When the vehicle was launched to the S path, tracking performance was better when we receive RCS in Goheung than in Jeju. In the case of using the monostatic radar system, when the vehicle was launched to the L path, tracking performance was better when we receive RCS in Goheung than in Jeju. When the vehicle was launched to the S path, tracking performance was better when we receive RCS in Jeju than in Goheung.

This paper presents a method to design Wilkinson power divider using transmission lines less than quarter wave length. The transmission lines less than quarter wave length of Wilkinson power divider is compensated by parallel capacitors. Therefore, this is helpful to reduce circuit size and to enhance productivity. The measurement results reveal that the insertion loss is 0.82 dB at 28 GHz. The measured return loss is better than 10 dB in the whole band of interest (20–40 GHz). The Wilkinson power divider is fabricated using 65 nm 1P9M CMOS technology.

In this paper, we defined the concept of the grouped distributed objects, as a logical unit of distributed application service, and developed a distributed programming developing tool-kit based on object group model (OGM-DPD Tool-Kit). This tool-kit can provide not only dynamic binding strategy among distributed objects and distributed services using the distributed object group framework (DOGF) we constructed before, but also implementation of distributed applications easily. Based on the DOGF, this OGM-DPD tool-kit provides the functionalities of the register/withdraw management, the access security management for individual distributed object, and the object name/property management as group units in the point of view of distributed object management. In the point of view of distributed service, our tool-kit includes the DOGF that can support naming service, dynamic binding service, replication service, and load balance service for distributed application services. In this paper, we in details specified the object group model and the architecture of the DOGF supporting this tool-kit. finally, we implemented a simple distributed application using this tool-kit, and showed the execution of this application to verify the executabilities of the distributed object group management and the distributed services described above.

The frequencies of γ-ray-induced micronuclei (MN) in cytokinesis-blocked (CB) lymphocytes at several doses were measured in three donors of four species (human, goat, rabbit, mouse). Measurements performed after irradiation showed a dose-related increases in MN frequency in each of the donors studied. The relative sensitivity of mouse in spleen lymphocytes (SLs), goat in peripheral blood lymphocytes (PBLs) and rabbit PBLs compared with human PBLs was estimated by best fitting linear-quadratic model based on the radiation-induced MN data over the range from 0 to 400 cGy. In the case of MN frequency with 0.2, the relative sensitivities of mouse SLs, goat PBLs and rabbit PBLs were 1.67, 0.98 and 0.39, respectively. These data indicate that the induction of MN in CB cells following irradiation is similar in human and goat PBLs, and PBLs from rabbit were much less sensitive to the MN induction effects of γ-radiation than those from human. Compared with the radiation-induced MN formation in the PBLs of human, the SLs of mouse were more radiosensitive.

Purpose: Many recent studies have reported on the feasibility and usefulness of laparoscopy assisted distal gastrectomy (LADG) for treating early gastric cancer. On the other hand, there has been few reports about laparoscopy assisted total gastrectomy (LATG) because upper located gastric cancer is relatively rare and the surgical technique is more difficult than that for LADG, We now present our procedure and results of performing LATG for the gastric cancer located in the upper or middle portion of the stomach. Materials and Methods: From Jan 2005 to Sep 2007, 96 patients underwent LATG by four surgeons at the Asan Medical Center, Seoul, Korea. Among them, 48 consecutive patients who were operated on by asingle surgeon were analyzed with respect to the clinicopathological features, the surgical results and the postoperative courses with using the prospectively collected laparoscopy surgery data. Results: There was no conversion to open surgery during LATG. For all the reconstructions, Roux-en Y esophago-jejunostomy and D1+beta lymphadenectomy were the standard procedures. The mean operation time was minutes. The mean total number of retrieved lymph nodes was (range: ) and all the patients had a clear proximal resection margin in their final pathologic reports. The mean time to passing gas, first oral feeding and discharge from the hospital was 2.98, 3.67 and 7.08 days, respectively. There were 5 surgical complications and 2 non-surgical complications for 5 (10.4%) patients, and there was no mortality. None of the patients needed operation because of complications and they recovered with conservative treatments. The mean operation time remained constant after 20 cases and so a learning curve was present. The morbidity rate was not different between the two periods, but the postoperative course was significantly better after the learning curve. Analysis of the factors contributing to the postoperative morbidity, with using logistic regression analysis, showed that the 8MI is the only contributing factor forpostoperative complications (P=0.029, HR=2.513, 95% CI=1.097-5.755). Conclusions: LATG with regional lymph node dissection for upper and middle early gastric cancer is considered to be a safe, feasible method that showed an excellent postoperative course and acceptable morbidity. BMI should be considered in the patient selection at the beginning period because of the impact of the BMI on the postoperative morbidity.

Purpose: Laparoscopic surgery for gastric cancer was introduced in the past decade because it was considered less invasive than open surgery, and this results in less postoperative pain, faster recovery and an improved quality of life. Several studies have demonstrated the safety and feasibility of this procedure. We examined the outcome of performing laparoscopic surgery for gastric cancer over the last two year. Materials and Methods: From April 2004 to December 2006, 329 patients with gastric adenocarcinoma underwent a laparoscopy-assisted distal gastrectomy with lymph node dissection. The data was retrospectively reviewed in terms of the clinicopathologic findings, the perioperative outcomes and the complications. Results: The total patient group was comprised 196 men (59.6%) and 133 women (40.4%). The mean BMI was 23.6 and the mean tumor size was 2.7 cm. The mean number of harvested lymph node was 22.7, and this was 18.6 before 30 cases and 23.1 after 30 cases, and the difference was significant (P=0.02). The mean operation time was 180.9 min, and this was than 287.9 min before 30 cases and 170.2 min after 30 cases. After 30 cases, there was a significant improvement of the operation time (P

Purpose: The laparoscopy assisted gastrectomy has been increasingly reported as the treatment of choice for early gastric cancer. However, expert surgeons, who have performed a conventional open gastrectomy for a long time, tend to have a negative attitude toward laparoscopic procedures. The aim of this study was to determine the learning curve of a laparoscopy assisted distal gastrectomy (LADG) for a surgeon expert in performing an open gastrectomy and to analyze the factors that have an effect on a LADG. Materials and Methods: Between April 2005 and March 2006, 62 patients underwent a LADG with D1+beta lymph-node dissection. The 62 patients were divided into 10 sequential groups with 6 cases in each group (the last group was 8 cases), and the time required to reach the plateau of the learning curve was determined by examining the average operative times of these 10 groups. Other factors, such as sex, BMI, complications, transfusion requirements, the number of retrieved lymph nodes, and change of postoperative hemoglobin level, were also analyzed. Results: With the group (after 30 cases), the operative time reached a plateau (average: 170 min/operation). The differences between before the case and after the case with respect to changes in the postoperative hemoglobin level, the number of retrieved lymph nodes, the transfusion requirements, and the complications rate were not significant. Conclusion: According to an analysis of the operative time, experience with 30 LADGs in patients with early gastric cancer is the point at which the plateau of the learning curve (7 months) is reached. Abundant experience with a conventional open gastrectomy and a well-organized laparoscopic surgery team are important factors in overcoming the learning curie earlier.