• Journal of Navigation and Port Research
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• v.28 no.6
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• pp.469-474
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• 2004

In this paper, we study the posture control of an underwater vehicle with nonholonomic constraint. Generally, systems with nonholnomic constraints cannot be stabilized to an equilibrium points by smooth state feedback control. For the nonholonomic underwater vehicle system, we applied coordinate transformation to get multi-chained system We proposed non smooth feedback controller using backstepping method for stabilizing the multi chained form system Applying inverse input transformation to the non smooth feedback controller, we can get posture controller of the underwater vehicle with nonholonomic constraint. The proposed control scheme is applied to the posture control qf an underwater vehicle and verified the effectiveness of control strategy by numerical simulation.

• Journal of Navigation and Port Research
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• v.28 no.8
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• pp.721-726
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• 2004

This study was performed to analyze the operation system of transfer crane to improve the reality of yard operation rules in container terminal and present the applicable method of operation rules to apply the operation priority. And we derived the procedure to estimate the maximum number of waiting truck based on the waiting of truck and the occupancy of driving lane in yard, and analyzed the constraint state of space. To solve the space constraint, we provided a multi-job principle to define the space resource and described the solution and sequence diagram for the principle.

• Journal of Chest Surgery
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• v.50 no.5
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• pp.339-345
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• 2017

Background: In recent years, single-port video-assisted thoracoscopic surgery (VATS) for lobectomy in non-small cell lung cancer (NSCLC) patients has become increasingly common. The objective of this study was to compare the feasibility and safety of single-port and triple-port VATS lobectomy. Methods: A total of 73 patients with NSCLC who underwent VATS lobectomy from December 2011 to August 2016 were retrospectively reviewed, including 47 in the triple-port group and 26 in the single-port group. Statistical analysis was performed after propensity score matching. Patients were matched on a 1-to-1 basis. Results: Operative time and intraoperative blood loss in the triple-port group and the single-port group were similar ($189.4{\pm}50.8minutes$ vs. $205.4{\pm}50.6minutes$, p=0.259; $286.5{\pm}531.0mL$ vs. $314.6{\pm}513.1mL$, p=0.813). There were no cases of morbidity or mortality. No significant differences in complications or the total number of dissected lymph nodes were found between the 2 groups. In the single-port group, more mediastinal lymph nodes were dissected than in the triple-port group ($1.7{\pm}0.6$ vs. $1.2{\pm}0.5$, p=0.011). Both groups had 1 patient with bronchopleural fistula. Chest tube duration and postoperative hospital stay were shorter in the single-port group than in the triple-port group ($8.7{\pm}5.1days$ vs. $6.2{\pm}6.6days$, p=0.130; $11.7{\pm}6.1days$ vs. $9.5{\pm}6.4days$, p=0.226). However, the differences were not statistically significant. In the single-port group, the rate of conversion to multi-port VATS lobectomy was 11.5% (3 of 26). The rates of conversion to open thoracotomy in the triple-port and single-port groups were 7.7% and 3.8%, respectively (p=1.000). Conclusion: In comparison with the triple-port group, single-port VATS lobectomy showed similar results in safety and efficacy, indicating that single-port VATS lobectomy is a feasible and safe option for lung cancer patients.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.103-104
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• 1992

Automatic transmission of data from the blood analyzer to the request site is one of the most important part in hospital computerization. We have developed a system to automatically transmit the data from the atrial blood gas analyzer. In this system, HOST computer, FILE server, LAN(Local Area Network), 3270 Emulator and Multi-port card were integrated. Also, 3 blood gas analyser(NOVA Inc., USA) were connected to a single multi-port card which is attached in a personal computer for data acquisition. When specimen is collected from sampling sites, it is transfered to the lab. After analysis, the result is transmitted to the personal computer via serial communication between machine and multi-port card using interrupt method. Then, the patient's information (Name, Sex, etc.) is obtained from the HOST computer througth the emulator. The combined data(patient information & lab data) is transmitted to the each request site via LAN automatically. From the collected data, patient's previous data could be reviewed, and it could be used for the various statistics and the flow chart for clinical research. Also, we found that this system reduces the personal labor.

• Journal of Chest Surgery
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• v.55 no.1
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• pp.44-48
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• 2022

Background: Although classical multi-port video-assisted thoracic surgery has been widely performed, single-incision thoracoscopic surgery (SITS) is a popular surgical technique for the treatment of primary spontaneous pneumothorax (PSP). However, the inconvenient alignment of instruments and the limited field of view occasionally make surgeons convert from SITS to multi-port surgery or extend the incision. This study aimed to present an easy and safe SITS technique for PSP using a spinal needle. Methods: In total, 139 patients underwent SITS between May 2011 and December 2017. We used a spinal needle to hook the bulla or bleb, and wedge resection was performed through a small incision. Patients' medical records were reviewed retrospectively, and a telephone survey was conducted to investigate the recurrence rate. Results: The mean age of the 139 patients was 23.62±9.60 years. The mean operative time was 36.69±14.64 minutes, and multi-port conversion was not performed. The mean postoperative hospital stay was 3.00±0.78 days, and the mean indwelling chest tube duration was 1.97±0.77 days. No complications were observed. In the mean follow-up period of 86.75±23.20 months, recurrence of pneumothorax was found in 3 patients. Conclusion: We suggest that SITS for PSP with the aid of a spinal needle to replace a grasper is a safe and easy technique that only requires a small incision.

• Journal of Drive and Control
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• v.10 no.1
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• pp.7-13
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• 2013

Port size 80mm or above large-flow type solenoid valves are extensively used in dust collector and power plants. These multi-stage solenoid valve have few problem. first, multi-solenoid valves are almost depend on imports and there are weak in the brine environment and the low energy efficiency. Because these problem, increased the necessity of research on the development of large flow and high pressure type solenoid valves. In this study, describe the design method of multi-stage solenoid test bench and confirm the influence valve performance on several parameter such as diaphragm orifice diameter. At first, each part has modeled by AMESim simulation tool and combining them. This AMESim virtual multi-stage solenoid valve found influence valve performance on the valve parameter. Finally developed the multi-stage solenoid valve and verified that performance on experimental result.

• Journal of Navigation and Port Research
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• v.44 no.1
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• pp.10-19
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• 2020

Port Gyeongin was developed as a multi-functional port equipped with container and general port facilities and could be linked with nearby tourist attractions. However, it has experienced difficulties from the limitation of being a small port, duplicating functions, and lacking an interlink with nearby ports. Nonetheless, resident companies that need logistics facilities in Port Gyeongin or nearby ports process specific import and export goods such as wood, steel, and industrial products through Port Gyeongin because of the characteristics of the port. From this perspective, it is critical to establish a measure to promote Port Gyeongin through utility analysis of the stakeholders in Port Gyeongin. In this regard, the purpose of this study was to analyze the preference of stakeholders in Port Gyeongin using conjoint analysis and propose a difference in the preference of the stakeholders. Study results show that the terminal group, shippers, and tenant companies considered the berthing capacity, incentive scale, and port logistics cost as the most critical matters, respectively. The stakeholders in Port Gyeongin should recognize the difference in critical matters, and be equipped with shipper discovery and institutional arrangement according to the characteristics of Port Gyeongin such as cooperation with related institutions and inter-collaboration between operating companies to promote Port Gyeongin.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.247-253
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• 2004

As a large scale port development in coastal waters proceeds step by step and populations in the vicinity of port are getting increased, the issue on "how to dispose the treated municipal water and wastewater in harbor" brings peoples′ concern. The submarine outfall system discharges the primary or secondary treated effluent at the coastline or in deep water, or between these two. The effluent, which has a density similar to that of fresh water, rises to the sea surface forming plume or jet, together with entraining the surrounding sea water and becomes very dilute. We intended in this paper to investigate the impact on dilution of effluent and the behavior of flume under the conditions of the seasonal and spatial temperature variations, which have not been noticeable in designing effective marine outfall system. To predict and analyze the behaviour and dilution characteristics of plume not just with the effluent temperature, but also with the seasonal variation of temperature of surround water and tidal changes, CORMIX(Cornell Mixing Zone Expert System)-GI have been applied. The results should be used with caution in evaluation the mixing zone characteristics of discharged water. We hope to help for the effective operation of outfall system, probable outfall design, protection of water quality, and warm water discharges from a power plant, etc.

• Journal of the Korean Institute of Navigation
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• v.13 no.1
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• pp.55-61
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• 1989

Nowadays much efforts for evaluating the productivity of port physical distribution system to meet the rapid change of the port and shipping circumstances has been made continuously all over the world. The major part of these efforts is the improvement of the productivity of cargo handling system. The cargo equipment system as infrastructure in the cargo handling system is organized well in some degrees, but the management system of manpower as upper structure is still remained in an insufficient degree. There is little study, so far, on a systematic research for the management of port labor gang, and even those were mainly depended on rule of thumb. The object of this study is to introduce the method of optimal allocation and assignment for the labor gang in single ship, which was suggested as a first stage in dealing with them generally. The problem of optimal allocation and assignment of the labor gang can be (I) formalized with multi-stage allocation and assignment of the labor gang can be. (II) dealt with two stages in form of hierarchic structure and moreover, (III) The optimal size of labor gang was obtained through dynamic programming from the point of minimizing the summation of labor gang in every stage, (IV) For the problem of optimal assignment, the optimal policy was determined at the point of minimizing the summation of movement between hatches.

• International Journal of Automotive Technology
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• v.5 no.1
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• pp.9-16
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• 2004

An experimental study was carried out to characterize the spray atomization process of micro-machined port fuel injectors with a piezoelectric atomization device, which can generate pressure pulsations through vibration of a piezoelectric transducer. In this study, several types of micro-machined arrays such as 30∼200-microns of hole arrays were tested. Both a dual-stream and a central-port injectors with micro-machined arrays were tested and compared with normal port fuel injectors. The spray visualization was conducted to characterize overall spray structure and phase Doppler particle analyzer (PDPA) system was used to quantify the droplet size and velocity. In addition, the pressure history was recorded by using digitized signal from pressure transducer. The results showed that modulation is effective to the spray atomization for tested injectors and atomization performance depends on injector design factors, orifice sizes, and frequency and power of the modulator. A number of resonance frequencies of the modulator was modified by injector parameters and temperature. In addition, our results suggested that design of sufficient space among holes is critical to avoid droplet coalescence in the multi-hole micro-machined injectors.