• Journal of the Korean Arthroscopy Society
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• v.4 no.2
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• pp.159-165
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• 2000

Purpose : Endoscopic carpal tunnel release technique was developed and has being used to decrease postoperative morbidity and complications. The purpose of this study was to evaluate the clinical results and clinical usefulness of endoscopic carpal tunnel release using single portal technique. Methods and Materials : 18 carpal tunnel syndrome patients who were diagnosed by means of clinical symptoms, physical examination, and electrodiagnostic study had endoscopic carpal tunnel release using single portal technique with about 1 cm oblique wrist incision on 30 hands. And then they were followed-up and reviewed in the same way. Late results of operation were analysed by grading system according to patient's own assessments of relief of symptoms at the final fellow-up. The follow-up period ranged 6 to 13 months from surgery. Results : There were postoperative improvements with respect to clinical symptoms, physical examination, and electrodiagnostic study. 23 of 30 hands$(76.7\%)$ had complete resolution of symptoms. 27 hands$(90\%)$ were able to return to normal activities and work within 6 weeks, and 30 hands$(100\%)$ returned within 8 weeks. In grip strength study, 29 hands$(96.6\%)$ regained preoperative strength in 6 months. 12 of 22 hands$(55\%)$ had improvement with respect to thenar atrophy within 6 months. Late results were as follows . 23 hands$(76.7\%)$ was graded as excellent, 6 hands$(20\%)$ graded as good and 1 hand$(3.3\%)$ graded as fair, and there was no poor result. Conclusion : We think that endoscopic carpal tunnel release with single portal technique is technically safe and simple, if the surgeon takes step to stay within the safety zone based on local anatomy and selects an appropriate patient and that endoscopic carpal tunnel release does have advantages over open release. We agree that the surgeon must be prepared to perform an open technique, if technical difficulties arise, difficulty in introducing the device into the carpal tunnel is encountered, or the transverse fibers of the transverse carpal ligaments are not clearly seen.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.287-304
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• 2007

This study was carried out to investigate spatio-temporal variations of benthic environment and macrobenthic polychaete communities in Gamak Bay where excessive organic matters from untreated sewage effluents and fish and shellfish farming activities have been accumulated in certain regions. Such environmental variables as sediment composition, organic content, acid volatile sulfide and dissolved oxygen content etc. were measured and polychaete specimens were taken in September 1999 and February 2000. In September 1999, organic contents were up to three times higher in the northwestern part of the bay and the area closed to Gukdong harbor than in the rest of the bay. In particular, benthic environment of the northwestern part of the bay was extremely deteriorated by the occurrence of hypoxia and highly concentrated sulfide. Of 28 stations investigated in summer, 5 stations located in the northwestern part were azoic. In the rest of the stations, a total of 119 polychaete species were sampled with a mean density of 900 $ind./m^2$. While species richness was higher in the entrance and central part of the bay where water exchanges with open sea were relatively active, density was higher in the moderately enriched stations neighbouring Gukdong harbor and fish farms where such potential indicators of organic pollution as Aphelochaeta monilaris, Lumbrineris longifolia were largely dominant. In February 2000, a total of 81 polychaete species appeared with a mean density of 2,802 $ind./m^2$ from 12 stations sampled in winter. Azoic areas were recolonized by Capitella capitata, Pseudopolydora paucibranchiata and Dipolydora socialis which showed maximum density in the innermost station. On the other hand, the rest of the stations were dominated by Euchone alicaudata and Praxillella affinis. The configuration of the stations sampled in summer and winter on the multidimensional scaling plots reflected the position of each stations within the bay in which there were great differences in organic content, sulfide concentration and oxygen content rather than in sediment composition. Therefore, heterogeneities in polychaete community structure in Gamak Bay were primarily influenced by the degree of the disturbance depending on the position within the bay.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.413-419
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• 2019

Traffic routes typically have heavy traffic. Especially, the entrance of the route has a high risk of accidents occurring because of ships entering and exiting the port. However, almost of studies have focused on the distribution of traffic on the route. Thus, studies on the distribution between ships for passing through the route are insufficient. The purpose of this study was to analysis the traffic in the Busan north port No.1 route for one week. Based on present traffic conditions, one gate line was settled on the route with an analysis of traffic conditions. Based on the analysis data, each optimal time probability distribution between ships was divided into inbound/outbound and traffic volume. An analysis of the optimal probability distribution, was applied to 31 probability distributions divided into bounded, unbounded, non-negative, and advanced probability distribution. The KS test was applied for identifying three major optimal time probability distributions. According to the KS test results, the Wakeby distribution is the best optimal time probability distribution on the designated route. Although the optimal time probability distribution for other transportation studies such as on vehicles on highways is a non-negative probability distribution, this distribution is an advanced probability distribution. Thus, the application of major probability distribution for using other transportation studies is not applicable to this study Additionally, the distance between ships in actual traffic surveys and the distance estimated by the optimal probability distribution were compared. As a result of the comparison, those distances were fairly similar. However, this study was conducted in only one major port. Thus, it is necessary to investigate the time between ships and calculate a traffic volume on varying routes in future studies.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.1
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• pp.80-92
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• 1999

This study was conducted to describe the community structure of macrobenthos in Aenggang Bay, the southern coast of Korea. Sampling was performed seasonally using van Veen grab from October 1994 to August 1995. A total of 233 species occurred; polychaetes accounted for 90 species, crustaceans 66 species, and mollusks 46 species. The mean density of macrobenthos was 1,358 ind./$m^2$, and polychaetes accounted for 64% of total abundance with its density of 874 ind./$m^2$. Mean macrobenthic biomass was 261.96 gWWt/$m^2$, and echinoderms accounted for 52.6% of total biomass with its biomass of 137.76 gWWt/$m^2$. Dominant species were a serpulid worm, Ditrupa arientina (245 ind./$m^2$), a cirratulid worm, Tharyx sp. (166 ind./$m^2$), and a scaphopod Fustaria nipponica (132 ind./$m^2$). Ditrupa arientina and Fustaria nipponica were distributed mainly in the mouth of Aenggang Bay, whereas Tharyx sp. showed its high density in the central region of the bay. The study area showed a regional difference in species richness, abundance, and biomass; the eastern region of the bay sustained relatively more abundant and richer macrobenthos than the western part. The study area could be divided into 5 regions by the cluster analysis based on the species composition of macrobenthos; the inner bay, two central regions, and two mouth areas of the bay.

• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.45-55
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• 2004

The paper describes the rainfall-runoff. soil moisture distribution and subsurface flow of 'U-shaped Goll' valley head slope to evaluate quantitatively the interaction between the water circulation system and geomorphic development. The findings are as follows: The fissure and the pipe entrance in front of 'U-shaped Goll' introduce a lot of direct runoff into either the soil pipe or the soil layer to accelerate the erosion of the soil layer, so that they are likely to contribute to the expansion and development of the soil pipe. Most of soil water is to be drained in pipe flow, while some of remaining soil water is to be fed into groundwater. Therefore, low rainfall intensity is thought to let both the groundwater level and the pipe flow react sensitively by the effects of the precedent rainfall even at events: As a result, the soil pipe is said to be an important factor having influence upon the material balance of 'U-shaped Goll' valley head slope. On the other hand, the groundwater shows greater specific flux at the top than at the bottom, and relatively larger specific flux is applied to the top to make 'U-shaped Goll' valley head slope go back to the top.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.371-374
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• 2012

본 연구는 "사이클론과 관성충돌 및 백필터의 제진원리를 일체화한 고효율 멀티 제진시스템의 최적화 설계를 위한 수치 해석적 연구(I) : 집진기 입구 최적화 설계"에 이은 일련의 연구로서 앞선 연구에서 도출된 사이클론부 하단 벤츄리(Venturi)에서의 강한 하향 기류의 가속에 따른 분진 재비산 가능성에 대한 추가적 검토를 위한 연구이다. 사이클론부를 통과한 기류가 상향 흐름으로 방향을 전환할때 좀 더 가속시켜 빠르게 곡률반경을 형성하여 조대 입자의 분리를 극대화시키기 위한 목적으로 사이클론부 하단을 벤츄리 형상으로 설계하였으나, 유동장 분석 결과 벤츄리를 통과한 처리가스 흐름이 가속되면서 호퍼 하단까지 약 4~5 m/s의 강한 하향 흐름을 형성하고 호퍼 하부의 말단 부근에서 상향 흐름으로 방향 전환을 하고 있는 것으로 예측됨에 따라 설계 의도와는 달리 벤츄리 설치시 호퍼 하단에 포집된 분진의 재비산을 예방하는데는 크게 역할을 하지 못하는 것으로 나타났다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.195-202
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• 1987

The flow characteristics in the shallow open channel bends are investigated, whose total angles were 30, 60, 90, 120, 150 and 180 in degree, and whose bed frictions were relatively rough(C=30) and smooth(C=60), respectively. The terms analyzed in this study are the water surface profile, the distribution of velocity and the flow direction, relating to the various total angles in the bends. The maximum depth in the bends could be found at the outside section of the location of $15^{\circ}$ local angle from the bend inlet, having no relation to the total angle and bed friction. It is supposed that the path of maximum velocities is especially influenced by the bottom friction when the total angles are bigger than 150 in degree, approximately. The ratio of the superelevation to the velocity head seems to increase as the total angle of the bends increases. The flow direction is skewed to the inner side at the bend inlet, and skewed to the outside at the bend outlet, regardless of their total angles.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.654-664
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• 1998

Seasonal variation in species composition and abundance of pelagic fish in Chonsu Bay were determined by analyzing monthly samples collected using a set net from March, 1992 to January, 1993. The data in this study were compared with those of 1981$\~$82. Of 63 species identified, Engraulis japonicus, Ammodytes penonatus, Enedrias fangi and Sardinella zunasi predominated in abundance. Especially E.japonicus occupied $87\%$ of total number of individuals. In spling, fish abundance increased by recruitment of lariat E. fanti as well as adults of E. japonicus, A. personatus and S. zunasi. These adults moved towards the open sea after spawning in early summer. A large number of juveniles was then collected from August until December. The seasonal change in species composition from the present study showed a similar trend to that occurred in 1981$\~$82. However, larger number of pelagic fish was caught in 1992$\~$93 than in 1981$\~$82. This result seems to be related to the higher water temperature (>$2^{\circ}C$) than the average mean temperature in spring and autumn, implying that higher temperature provides favorable conditions for spawning and growth of the fish.

• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.217-225
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• 2019

This study describes a large recumbent fold, which occurs at the north entrance slope of the Batjae tunnel, Pyeongchang-gun, Gangwon-do, and interprets its formation mechanism. The several-hundred-meter scale fold, developed in the Jeongseon Limestone of the Paleozoic Joseon Supergroup, has a nearly horizontal axial plane and its head is facing north. Stretching lineations ($L_1$) observed on the composite foliations of bedding and axial plane cleavage plunge southward at about $10^{\circ}$. Small A-type or eye-shaped sheath folds together with S-shaped asymmetrical folds are often observed in the fold limbs and their axes are nearly parallel to the lineations ($L_1$) within center and rear parts of the fold. It is thus interpreted that the recumbent fold is a large sheath fold produced by the top-to-the-north ductile shearing due to the Songrim orogeny during the late Paleozoic to Triassic.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.321-327
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• 2019

The purpose of this study is paper is to improve the flow performance and to reduce the aerodynamic noise of air discharge system consisting of a centrifugal fan, ducts and a housing for the clothes dryer. Using computational fluid dynamics and acoustic analogy based on FW-H (Ffowcs-Williams and Hawkings) Eq., air flow field and acoustic fields of the air discharge system are investigated. To optimize aerodynamic performance and aerodynamic noise, the response surface method is employed. The two factors central composite design using the inflow and outflow angles of fan blades is adopted. The devised optimum design shows the reduction of turbulent kinetic energy in the ducts and the housing of the system, and as a result, the improved flow rate and reduce noise is confirmed. Finally, the experment using the proto-type manufactured usign the optimum design shows the increase of flow rate by 4.2 %.