• 천문학회보
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• 제38권1호
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• pp.64.2-64.2
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• 2013

Korea Astnonomy and Space Science Institute (KASI) operates two solar radio observing facilities, the Korean station of the e-CALLISTO and the Korean Solar Radio Burst Locator (KSRBL). The e-CALLISTO station had suffered from tracking problem for past several years. Since 2011, KASI has developed a new tracking system, and recently the antenna has regained the its sun-tracking capability and full day-time coverage. The KSRBL also suffered from the control computer breakdown last year. After one year of operational gap, the KSRBL restored its normal daily observation. We also expanded the data server storage capacity, to store the full original data of 25 ms integration time and 0.25 MHz frequency resolution, amounting to about 80 GB per day.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.17-28
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• 2011

Despite the fact that the deployment of sensor networks and target tracking could both be managed by taking full advantage of Voronoi diagrams, very little few have been made in this regard. In this paper, we designed an optimized barrier coverage and an energy-efficient clustering algorithm for forming Vonoroi-based Wireless Sensor Networks(WSN) in which we proposed a mobile target tracking scheme (CTT&MAV) that takes full advantage of Voronoi-diagram boundary to improve detectability. Simulations verified that CTT&MAV outperforms random walk, random waypoint, random direction and Gauss-Markov in terms of both the average hop distance that the mobile target moved before being detected and lower sensor death rate. Moreover, we demonstrate that our results are robust as realistic sensing models and also validate our observations through extensive simulations.

• Archives of Plastic Surgery
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• 제48권3호
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• pp.338-343
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• 2021

Purpura fulminans is a serious condition that can result in severe morbidity in the pediatric population. Although autologous skin grafts remain the gold standard for the coverage of partial- to full-thickness wounds, they have several limitations in pediatric patients, including the lack of planar donor sites, the risk of hemodynamic instability, and the limited graft thickness. In Singapore, an in-house skin culture laboratory has been available since 2005 for the use of cultured epithelial autografts (CEAs), especially in burn wounds. However, due to the fragility of CEAs, negative-pressure wound therapy (NPWT) dressings have been rarely used with CEAs. With several modifications, we report a successful case of NPWT applied over a CEA in an infant who sustained 30% total body surface area full-thickness wounds over the anterior abdomen, flank, and upper thigh secondary to purpura fulminans. We also describe the advantages of using NPWT dressing over a CEA, particularly in pediatric patients.

• 대한소아치과학회지
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• 제26권2호
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• pp.240-247
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• 1999

치아우식증, 외상, 발육성 결함으로 광범위한 수복이 필요한 유전치의 치료는 소아치과의사에게 있어 매우 까다로운 문제이다. 이상적인 수복술식은 강도, 내구성, 심미성과 장착의 효율성을 모두 갖추어야 한다. 이에 행동조절문제가 있는 어린이를 치료하는 기술적 문제를 더하면, 여러 가능한 수복 방법 중에서 적절한 술식을 선택하는 것은 어려운 일이다. 현재 사용되는 수복술식에는 복합레진의 접착을 사용한 celluloid strip crown, conventional stainless steel crown, open-faced stainless steel crown, commercially 및 chairside veneered stainless steel crown과 epoxy-coated stainless steel crown 등이 있다. 이 모든 술식이 나름대로의 기술적, 기능적 또는 심미적 단점을 갖고 있어 각각의 효율적이고 효과적인 사용을 위해서는 적절한 선택이 중요하다. 이에 저자는 이러한 여러 가지의 전장피개수복 방법을 사용해 유전치를 치료하여 그 결과를 보고하는 바이다.

• 지구물리와물리탐사
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• 제16권4호
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• pp.211-216
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• 2013

일반적으로 평활화 필터는 주변값들과의 차이를 감소시켜 함수를 정규화하는 역할을 한다. 따라서 완전파형역산에 평활화 필터를 적용하면 역산 해를 정규화 할 수 있으며 실제 지하 구조에 가까운 영상을 얻을 수 있다. 다만 단일 평활화 계수를 사용했을 때는 지층 형태나 속도변화에 관계없이 동일하게 평활화가 이루어지므로 지층간 경계면이나 단층 등의 구조가 불명확해지는 단점이 있다. 본 논문에서는 이러한 문제를 해결하기 위해 단일 평활화 계수가 아닌 역산 반복 과정에 따라 선택적으로 평활화 계수를 조정하는 정규화 기법을 개발하였다. 먼저 파형역산에 적합한 탐사자료의 주파수 대역과 그에 대응하는 파수 범위를 분석하였다. 분석한 파수 범위에 적합한 평활화 계수를 선정하기 위해 평활화 필터의 파수 스펙트럼에서 99백분위수에 해당하는 파수를 유효최대파수로 결정하였다. 선정된 평활화 계수를 반복역산에 따라 다르게 적용하여 여러 주파수를 동시에 이용하는 멀티-스케일 완전파형역산을 구현하였다. 암염 모델과 같은 속도대비가 큰 지질구조에 대해 성공적인 역산결과를 얻음으로써 본 연구에서 개발한 평활화 계수 선택기법이 효과적인 정규화 과정을 구현한다는 것을 알 수 있었다. 또한 무작위 잡음이 더해진 인공합성 음원모음 자료에 대한 수치예제를 통해 현장 자료에 대한 적용 가능성도 확인할 수 있었다.

• Archives of Plastic Surgery
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• 제42권3호
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• pp.334-340
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• 2015

Background Full-thickness skin grafts (FTSGs) are generally considered unreliable for coverage of full-thickness finger defects with bone or tendon exposure, and there are few clinical reports of its use in this context. However, animal studies have shown that an FTSG can survive over an avascular area ranging up to 12 mm in diameter. In our experience, the width of the exposed bones or tendons in full-thickness finger defects is <7 mm. Therefore, we covered the bone- or tendon-exposed defects of 16 fingers of 10 patients with FTSGs. Methods The surgical objectives were healthy granulation tissue formation in the wound bed, marginal de-epithelization of the normal skin surrounding the defect, preservation of the subdermal plexus of the central graft, and partial excision of the dermis along the graft margin. The donor site was the mastoid for small defects and the groin for large defects. Results Most of the grafts (15 of 16 fingers) survived without significant surgical complications and achieved satisfactory functional and aesthetic results. Minor complications included partial graft loss in one patient, a minimal extension deformity in two patients, a depression deformity in one patient, and mild hyperpigmentation in four patients. Conclusions We observed excellent graft survival with this method with no additional surgical injury of the normal finger, satisfactory functional and aesthetic outcomes, and no need for secondary debulking procedures. Potential disadvantages include an insufficient volume of soft tissue and graft hyperpigmentation. Therefore, FTSGs may be an option for treatment of full-thickness finger defects with bone or tendon exposure.

• 대한두경부종양학회지
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• 제4권1호
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• pp.21-28
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• 1988

Skin replacement in large cheek defects after excision of benign or malignant tumor on the face is a challenging task. The physical characteristics of cheek skin are matched best by adjacent skin. Various methods of reconstructing of the facial surface such as forehead flap, distant flap, or a full thickness or split thickness skin graft have replaced adjacent tissue for coverage in many cases. We have reviewed ten cases of aesthetic reconstruction of the face after resection of the facial skin tumor within the last 5 years. The first group of 3 patients were reconstructed with split thickness skin graft from the scalp or lower abdomen. The second group of patients were reconstructed with cheek flap. The third group of 3 patients were reconstructed with cervicofacial flap. The last 2 patients were reconstructed with nasolabial flap & island falp respectively. The advantages from our experience with various method of coverage are its hidden donor area & good color match with the facial skin & increased success rate.

• 한국사회복지학
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• 제45권
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• pp.72-100
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• 2001

Despite the rapid expansion of social security coverage in the 1990s, many wage earners in Korea, especially the majority of the nonstandard workforce are excluded in the social insurance programs. In this regards, the purpose of this paper is to analyze causes of the exclusion of nonstandard workers to the social insurance scheme and to suggest the feasible policy options. Through this paper, four arguments are addressed as follows. First, the main issue for exclusion from coverage of those workers is that they have no entitlement to social insurance. This is not an issue of that they fall below hours or income thresholds for the entitlement Second, the top-down process of the extension in the Korean social insurances have divided the wage earners into two groups, the insider (the included) and the outsider (the excluded). Many nonstandard workers belong to the latter category. Third, the social insurance systems have been designed for the regular workers who were characterized by a full-time with some degree of stability. Reform designed to cope with the growth of nonstandard workers must build on the existing structure of social insurance. Finally, the governance capacity by social security administration body must be improved in order to provide a basic social protection for those workers. For that, four separated social insurance administration bodies could be unified to one administrative body, or tax and contribution of social insurance could be collected by one integrated administration body, the National Tax Service.

• Journal of Astronomy and Space Sciences
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• 제36권3호
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• pp.213-223
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• 2019

This paper analyzes delta-Vs to maintain an extremely low altitude on the Moon and investigates the possibilities of performing a CubeSat mission. To formulate the station-keeping (SK) problem at an extremely low altitude, current work has utilized real-flight performance proven software, the Systems Tool Kit Astrogator by Analytical Graphics Inc. With a high-fidelity force model, properties of SK maneuver delta-Vs to maintain an extremely low altitude are successfully derived with respect to different sets of reference orbits; of different altitudes as well as deadband limits. The effect of the degree and order selection of lunar gravitational harmonics on the overall SK maneuver strategy is also analyzed. Based on the derived SK maneuver delta-V costs, the possibilities of performing a CubeSat mission are analyzed with the expected mission lifetime by applying the current flight-proven miniaturized propulsion system performances. Moreover, the lunar surface coverage as well as the orbital characteristics of a candidate reference orbit are discussed. As a result, it is concluded that an approximately 15-kg class CubeSat could maintain an orbit (30-50 km reference altitude having ${\pm}10km$ deadband limits) around the Moon for 1-6 months and provide almost full coverage of the lunar surface.

• Archives of Plastic Surgery
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• 제46권3호
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• pp.255-261
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• 2019

Cross-leg flaps are a useful reconstructive option for complex lower limb defects when free flaps cannot be performed owing to vessel damage. We describe the use of the extended distally based sural artery flap in a cross-leg fashion for lower extremity coverage in three patients. To maximise the viability of these extended flaps, a delay was performed by raising them in a bipedicled fashion before gradual division of the tip over 5 to 7 days for cross-leg transfer. Rigid coupling of the lower limbs with external fixators was critical in preventing flap avulsion and to promote neovascular takeover. The pedicle was gradually divided over the ensuing 7 to 14 days before full flap inset and removal of the external fixators. In all three patients, the flaps survived with no complications and successful coverage of the critical defect was achieved. One patient developed a grade 2 pressure injury on his heel that resolved with conservative dressings. The donor sites and external fixator pin wounds healed well, with no functional morbidity. The cross-leg extended distally based sural artery flap is a reliable reconstructive option in challenging scenarios. Adequate flap delay, manoeuvres to reduce congestion, and postoperative rigid immobilization are key to a successful outcome.