• Korean Journal of Computational Design and Engineering
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• v.17 no.3
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• pp.198-207
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• 2012

This paper presents an overview of automated robotic system for skull drilling, which is performed to access for some neurosurgical interventions, such as brain tumor resection. Currently surgeons use automatic-releasing cranial perforators. The drilling procedure must be performed very carefully to avoid penetration of brain nerve structures; however failure cases are reported. The presented prototype system utilizes both preoperative and intraoperative information. Preoperative CT image is used for robot path planning. A NeuroMate robot with a six-DOF force sensor at the end effector is used for intraoperative operation. Intraoperative cutting force from the force sensor is the key information to revise an initial registration and preoperative path plans. Some possibilities are verified by path simulation but cadaver experiments are required for validation of this prototype.

• Tunnel and Underground Space
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• v.34 no.5
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• pp.477-502
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• 2024

To effectively dispose of high-level radioactive waste, it is crucial to understand the geological characteristics of the deep rock at the disposal site where the disposal facility will be located. Deep drilling is essential in this process and can obtain multidisciplinary deep rock characteristics by conducting tests using recovered cores and various tests using boreholes. However, in Korea, there are currently no established guidelines or procedures for deep drilling aimed at sit investigation and characterization for high-level radioactive waste disposal. This report proposes a deep drilling procedure based on five years from 2020 of multipurpose deep drilling experience conducted for various rock types by the Korea Institute of Geoscience and Mineral Resources. The proposed procedure includes various processes such as health, safety, and environments, pre-drilling work, drilling work, circulating drilling water management, site characterization evaluation parameter acquisition tests and measurements, and sampling. These procedures will need to be continuously revised and amended in the future to meet the needs of drilling and HLW disposal industries and related fields, as well as to strengthen quality assurance under the Nuclear Safety Act.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.865-874
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• 2020

Offshore drilling units have a very dangerous working conditions due to the harsh working environment of the ocean and the high possibility of fire or explosion. This study would identify the hazards that emerge from the marine environment in the operation and maintenance phase of offshore drilling units and show how these hazards can be reduced through risk assessment/management. Various risk reduction and management measures were first reviewed, and Job Safety Analysis (JSA) was selected as the risk assessment technique of this study. In order to understand the characteristics of offshore drilling operations, accident statistics of onshore and offshore drilling were analyzed and compared with each other, and major risk factors for offshore drilling were derived. The jobs in which offshore drilling accidents occur more frequently than onshore drilling was analyzed as the job of fastening, transporting and moving pipes and various materials. This result is due to the limited space of the ocean and the work environment that is prone to being shaken by wind, waves and ocean currents. Based on these statistical results, the job of picking and making up drill pipes was selected as a high-risk job, and JSA was performed as an example. A detailed safety check procedure is proposed so that workers can fully recognize the danger and perform work in a safe state that has been confirmed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.183-187
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• 2012

This study is to prepare the emergency response procedures for an unmanned LRT (Light Rapid Transit) which is being commercially operated recently. This emergency response procedure adds several particular characteristics which happens in the hardware and software aspects at the unmanned LRT in addition to the present emergency response procedures. The emergency response procedure has to conform to the emergency response planning. For doing that this emergency response procedure includes three important sub systems. First of all, the functional emergency response system has been developed. Secondly, Standard Operation Procedure (SOP) is suggested for the better and faster emergency response between emergency response personnel and institutes. Thirdly, emergency response training and drilling system is also provided for emergency response personnel. Finally, a software program for emergency response training and drilling will be developed and suggested to be used for the emergency response personnel.

• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.76-80
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• 2004

Purpose: We assessed the results of open treatment of anterior impingement syndrome of the ankle in elite level soccer players and concomitant injuries were idenfied. Materials and Methods: We retrospectively reviewed twenty one elite level soccer players diagnosed with anterior impingement syndrome who underwent open debridement between January 1997 and January 2002. All were men and the mean age at the operation was 21 years (range 16 to 27). The mean follow-up duration was 31 months (13 to 71). Concomitant abnormalities were idenfied through physical examination, bone scan and MRI. On a preoperative lateral radiograph, patients were classified according to McDermott's stage. Anteromedial or anterolateral approach was used at the operation and osteophyte was removed with osteotome and rongeur. When chronic ankle instability was accompanying, we performed Modified Brostrom-Gould procedure and for osteochondral lesion, multiple drilling was applied. The Ogilvie-Harris scoring system was used as a clinical scale to evaluate pain, swelling, stiffness and limitation of activity. The results were scored as excellent (15 to 16 points), good (13 to 14) and otherwise unsatisfactory. The time to return to full activity including sports activity was determined. Results: Eighteen of twenty one patients had an excellent outcome. Three patients were graded unsatisfactory and two of them abandoned their career due to the persistence of residual pain. Concomitant abnormalities were found including twelve cases of chronic ankle instability, three cases of osteochondral lesion and two cases of flexor hallucis longus tendinitis. Conclusion: Open debridement was successfully applied to the elite level soccer player with anterior impingement syndrome of the ankle. Considerable coexistence of other abnormalities such as chronic ankle instability may encourage us to consider additional operative procedure.

• Steel and Composite Structures
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• v.44 no.2
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• pp.271-281
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• 2022

This study discusses challenges of running expandable profile liners (EPLs) to isolate trouble zones in directional section of a deep well, and summary the expandable profile liner technology (EPLT) field trial experience. Technically, the trial result reveals that it is feasible to apply the EPLT solving lost-circulation control problem and wellbore instability in the deep directional section. Propose schemes for optimizing the EPLT operation procedure to break through the existing bottleneck of EPLT in the deep directional section. Better-performing transition joints are developed to improve EPL string reliability in high borehole curvature section. High-performing and reliable expanders reduce the number of trips, offer excellent mechanical shaping efficiency, simplify the EPLT operation procedure. Application of the expansion and repair integrated tool could minimize the risk of insufficient expansion and increase the operational length of the EPL string. The new welding process and integrated automatic welding equipment improve the welding quality and EPL string structural integrity. These optimization schemes and recent new advancements in EPLT can bring significant economic benefits and promote the application of EPLT to meet future challenges.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.67-75
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• 2023

In this study, the dynamic characteristics of an offshore platform being installed and physical phenomena are analyzed from the perspective of interaction between operation and maneuvering simulation using a real-time Maneuvering & Operation simulator of Shipbuilding & Marine Simulation Center at Tongmyong University. It was simulated to install the semi-submersible drilling rig moored by 8 mooring lines according to a scenario that is similar to it on the real sea, and 4 tug boats for position keeping of the rig and an offshore support vessel for hook-up of the mooring lines were operated. During the simulation, the motion, trajectory, tension of the objects were output in real time, and they were analyzed at each work procedure. This study about the simultaneous simulation of operation and maneuvering showed the detailed motion of the offshore platform and ships on the operation procedure and the interaction between operation and maneuvering in specific environment condition. Also, it confirmed that the simulation can be utilized to determine the possibility of offshore platform installation in specific situations.

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.212-216
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• 2011

Objective : It is well known that plate-to-disc distance (POD) is closely related to adjacent-level ossification following anterior cervical plate placement. The study was undertaken to compare the outcomes of two different anterior cervical plating methods for degenerative cervical condition. Specifically, the new method involves making holes for plate screws first with an air drill and then choosing a plate size. The other method was standard, that is, decide on the plate size first, locate the plate on the anterior vertebral body, and then drilling the screw holes. Our hypothesis was that the new technical tip may increase POD as compared with the standard anterior cervical plating procedure. Methods : We retrospectively reviewed 49 patients who had a solid fusion after anterior cervical arthrodesis with a plate for the treatment of cervical disc degeneration. Twenty-three patients underwent the new anterior cervical plating technique (Group A) and 26 patients underwent the standard technique (Group B). POD and ratios between POD to anterior body heights (ABH) were measured using postoperative lateral radiographs. In addition, operating times and clinical results were reviewed in all cases. Results : The mean durations of follow-up were $16.42{\pm}5.99$ (Group A) and $19.83{\pm}6.71$ (Group B) months, range 12 to 35 months. Of these parameters mentioned above, cephalad POD (5.43 versus 3.46 mm, p=0.005) and cephalad POD/ABH (0.36 versus 0.23, p=0.004) were significantly greater in the Group A, whereas operation time for two segment arthrodesis (141.9 versus 170.6 minutes, p=0.047) was significantly lower in the Group A. There were no significant difference between the two groups in caudal POD (5.92 versus 5.06 mm), caudal POO/ABH (0.37 versus 0.32) and clinical results. Conclusion : The new anterior cervical plating method represents an improvement over the standard method in terms of cephalad plate-to-disc distance and operating time.

• Bulletin of the Society of Naval Architects of Korea
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• v.54 no.4
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• pp.39-46
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• 2017

Jack-up drilling rigs are widely used in offshore oil and gas exploration industry. It is originally designed for use in the shallow waters less than 60m of water depth; there is growing demand for their use in deeper water depth over 150m and harsher environmental conditions. In this study, global in-place analysis of jack-up rig leg for North-sea oil well is performed through numerical analysis. Firstly, environmental conditions and seabed characteristics at the North-sea are collected and investigated measurements from survey report. Based on these data, design specifications are established and the overall basic design is performed. Dynamic characteristics of the jack-up rig for North-sea are considered in the global in-place analysis both leg and hull and the basic stability against overturning moment is also analyzed. The structural integrity of the jack-up rig leg/hull is verified through the code checks and the adequate safety margin is observed. The uncertainty in jack-up behaviour is greatly influenced by the uncertainties in the soil characteristics that determine the resistance of the foundation to the forces imposed by the jack-up structure. Among the risks above mentioned, the punch-through during pre-loading is the most frequently encountered foundation problem for jack-up rigs. The objective of this paper is to clarify the detailed structure and installation engineering matters for prove the structural safety of jack-up rigs during operation. With this intention the following items are addressed; - Characteristics of structural behavior considering soil effect against environmental loads - Modes of failure and related pre-loading procedure and parameters - Typical results of structural engineering and verification by actual measurement.