• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.4
• /
• pp.445-453
• /
• 2016

Objectives: The objective of this study is to assess relative safety level of the decompression tables in Ministry of Employment and Labor Public Notice No. 2014-28 in comparison with overseas decompression tables. Methods: Decompression tables in the Public Notice No. 2014-28 were compared with examples from Japan, the USA, Canada, and France in terms of ascent rate, surface intervals after exceptional exposures, oxygen decompression and allowable partial pressure, depth limits in air diving, no-decompression limits, and decompression time and methods. Results: Public Notice No. 2014-28 does not include air diving depth limits, exceptional exposure limits, mandatory surface intervals after exceptional exposures, oxygen decompression, and surface decompression schedules. Its decompression time was found to be the shortest among the five decompression tables. Conclusions: Public Notice No. 2014-28 has the lowest safety level in comparison with overseas decompression tables. Deck decompression chambers are not applicable due to no regulations on surface interval and oxygen use in the chamber for decompression.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.176-183
• /
• 2020

A ship has three types of diving systems (Diver Stage Diving, Wet Bell Diving and Scuba Diving) to carry out a search-and-rescue operation. To reduce the possibility of decompression sickness, any diving systems shall comply with the decompression procedure according to the decompression table corresponding to the diving depth and diving time. The decompression procedure is largely divided into two methods: underwater decompression and underwater-onboard decompression. In particular, the surface interval shall not exceed 5 minutes, which is the phase from underwater decompression to underwater-onboard decompression, in accordance with the U.S Navy Diving Manual. However, the surface interval is greater than 5 minutes as a result of using Wet Bell Diving. This paper describes the result of cause analysis and measurement with improved Wet Bell Diving. Using improved Wet Bell Diving reduced the surface interval to less than 5 minutes. The result of the research can be used for operation and improving the performance of diving systems.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.6
• /
• pp.790-797
• /
• 2015

This study tried to evaluate the safety and economical benefit of Nitrox-diving by comparing with Air diving. We used actual diving data which was recorded in construction site of the Busan-Geoje fixed link immersed tunnel in 2010. The study method was to assort and analyze the diving data by divers, depth, breathing air, and diving table. Furthermore, the study examined the possibility of outbreak decompression sickness by comparing Nitrox diving and Air diving in no-decompression limit time, decompression time, working time. As a result, this study confirms that if certain diver breathe Nitrox for diving and oxygen for decompression, not only the risk of decompression sickness could be minimized, but also duration of decompression could be shortened. Moreover, it was estimated that a remarkable difference(more than 3 times) between actual duration of underwater construction period and virtual construction period by using air. As a result, the study confirmed that Nitrox diving is more efficient and economical than Air diving in physically limited and hazardous diving environment.

• ETRI Journal
• /
• v.33 no.3
• /
• pp.374-381
• /
• 2011

A simple and effective compression method is proposed for multiple-scan testing. For a given test set, each test pattern is compressed from the view of slices. An encoding table exploiting seven types of frequently-occurring pattern is used. Compression is then achieved by mapping slice data into codewords. The decompression logic is small and easy to implement. It is also applicable to schemes adopting a single-scan chain. Experimental results show this method can achieve good compression effect.

• Journal of Preventive Medicine and Public Health
• /
• v.31 no.1 s.60
• /
• pp.139-156
• /
• 1998

Diving related disease including decompression sickness is an important occupational health problem and diving fishermen remain a fairly hazardous occupation in Korea. To prevent diving related disease, we investigate diving patterns, incidence of diving related diseases, and contributing factors of 433 diving fishermen of three coast interviewing and mailing questionnaire in 1996. Mean age of divers was 39.7 years, ranged from 24 to 58 years, 92.8% of these were male, and 58.4% of divers were high school graduates. Mean duration of work as a diver was 12.9 years, ranged from 2 to 40 years. It was found that 70.4% of divers were using hookah system, 22.2% of helmet, and only 2.5% SCUBA. About half of them have learned diving skills from other divers. The peak season of diving was from April to June and mean working days were 20.3 days per month during the peak season. On the average, the divers dived 5-6 times, ranged from 1 to 10 times a day with 51.1 minutes of diving time, ranged from 20 to 120 minutes, at 30 m or 40 m in depth, and 35.5 minute of interval on surface. Most divers ascended slowly making decompression stop, yet the decompression profile used was not based on any scientific knowledge except for their own experiences. It appeared that each diving system had slightly different diving patterns. There were 282(65.0%) divers that suffered from DCS in 1995 and 31.2% of divers were given recompression therapy at a medical facility since they worked as diving fishermen. Skin and musculoskeletal complaints were common symptoms of DCS and 39% of divers experienced a voiding difficulty. In univariate analysis, females have an increased frequency of DCS(93% vs 66% for males). Old age, long duration of work, helmet diving, diving time, diving depth, repetitive diving, and blow up were all contributing factors to DCS. It was found that most diving patterns exceed no decompression limit and did not use the standard decompression table. This suggests that most of divers are at high risk of developing diving related disease with prolonged dives and lengthy repetitive diving in deep depth. Considering the diving patterns and economic aspect of professional diving, the incidence of DCS among diving fishermen in Korea will not decrease in the near future. These findings suggest that periodical health surveillance for divers, and education of health and safety are important for reducing the risk of diving related disease in the population of diving fishermen.

• The Academic Congress of Korean Shoulder and Elbow Society
• /
• 2008.03a
• /
• pp.164-164
• /
• 2008

The beach-chair traction position is designed to allow the use of traction while allowing the surgeon to orient the shoulder in an upright position and convert to an open procedure, if necessary. The patient is placed in the beach-chair position under general anesthesia. A three-point shoulder holder (Arthrex, Naples, Florida) is attached to the rail of the operating table on the same side as the surgeon, whereas it is placed on the side opposite the surgeon in the lateral decubitus position. A shoulder traction and rotation sleeve (Arthrex) are affixed to the arm following the manufacturer's instructions. Positioning the thumb toward the closed side of the sleeve ensures a field for the anterior portion of the rotator cuff and prevents the tendency of the suspension apparatus to place the arm in internal rotation. The arm is maintained in 30 to 40 degree abduction and 30 to 40 degree flexion by controlling the length and height of the bar and the location of the universal clamp. The universal clamp allows multiple planes of adjustment to control abduction and forward movement of the arm. The sleeve is attached to the longitudinal traction cable using a sterile hook, and a lateral strap is secured around the proximal portion of the sleeve to the overhead traction cable to ensure a field for glenohumeral reconstruction. The use of a lateral strap permits ideal shoulder positioning for improved access to the anterior and inferior glenohumeral joint. The lateral strap can be released or removed to widen the subacromial space during subacromial decompression or rotator cuff repair. A 10-lb weight is attached to the longitudinal traction cable for an average-sized person.

• The Journal of the Korea Contents Association
• /
• v.11 no.2
• /
• pp.126-134
• /
• 2011

Recently, many researchers are interested in using join queries to correlate sensor readings stored in different regions. In the conventional algorithm, the preliminary join coordinator collects the synopsis from sensor nodes and determines a set of sensor readings that are required for processing the join query. Then, the base station collects only a part of sensor readings instead of whole readings and performs the final join process. However, it has a problem that incurs communication overhead for processing the preliminary join. In this paper, we propose a novel energy-efficient in-network join scheme that solves such a problem. The proposed scheme determines a preliminary join coordinator located to minimize the communication cost for the preliminary join. The coordinator prunes data that do not contribute to the join result and performs the compression of sensor readings in the early stage of the join processing. Therefore, the base station just collects a part of compressed sensor readings with the decompression table and determines the join result from them. In the result, the proposed scheme reduces communication costs for the preliminary join processing and prolongs the network lifetime.