• The Korean Journal of Pain
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• 제9권2호
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• pp.407-411
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• 1996

Stereotactic radiofrequency dorsal root ganglionotomy can be very useful procedures for the treatment of pain emanating from the lumbar segmental nerves. This procedure is reserved for patients who have failed conservative interventional treatments and in whom open surgical intervention is not an option. The advantages of the radiofrequency lesion method are presented, excellent control of the lesion process using temperature monitoring to quantify the lesion size, prevent boiling, and to produce differential destruction of neural tissue. The afferent fibers in the ventral root which are spared by dorsal rhizotomy but nerve fibers with their cells in the ganglion from either dorsal or ventral root can be destructed with stereotactic radiofrequency ganglionotomy. This technique is performed using a 100 mm cannula with a 5 mm active tip. Repeated lateral fluoroscopic view should be taken to make sure that cannlua still resides within the superior, dorsal quadrant or the foramen. With the cannula in this position, electrostimulation is performed and good paresthesia on the leg should be noted with 0.3 and 0.5 volt at 50 Hz stimulation. At 2Hz stimulation distinct dissociation between motor and sensory should be shown. Percutaneous lumbar ganglionotomy have carried out under local anesthesia on inpatient basis in 6 patients. A series of 5 patients with metastatic cancer pain and a patient with compression fracture have been relieved of pain without serious complications.

• 한국물환경학회지
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• 제32권1호
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• pp.70-79
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• 2016

Based on the soil moisture data assimilation suggested in the first paper (I), we estimated root zone soil moisture and evaluated drought severity using remotely sensed (RS) data. We tested the impacts of various spatial resolutions on soil moisture variations, and the model outputs showed that resolutions of more than 2-3 km resulted in over-/under-estimation of soil moisture values. Thus, we derived the 2 km resolution-scaled soil moisture dynamics and assessed the drought severity at the study sites (Chungmi-cheon sites 1 and 2) based on the estimated soil/root parameters and weather forcings. The drought indices at the sites were affected mainly by precipitation during the spring season, while both the precipitation and land surface characteristics influence the spatial distribution of drought during the rainy season. Also, the drought severity showed a periodic cycle, but additional research on drought cycles should be conducted using long-term historical data. Our proposed approach enabled estimation of daily root zone soil moisture dynamics and evaluation of drought severity at various spatial scales using MODIS data. Thus, this approach will facilitate efficient management of water resources.

• Journal of Chest Surgery
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• 제45권3호
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• pp.141-147
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• 2012

Background: Although the aortic valve-sparing procedure has gained popularity in recent years, it still remains challenging in patients with advanced aortic regurgitation (AR). We compared the long-term outcomes of the aortic valve-sparing procedure with the Bentall operation in patients with advanced aortic regurgitation secondary to aortic root dilatation. Materials and Methods: A retrospective review of 120 patients who underwent surgery for aortic root dilatation with moderate to severe AR between January 1999 and June 2009 was performed. Forty-eight patients underwent valve-sparing procedures (valve-sparing group), and 72 patients underwent the Bentall procedure (Bentall group). The two groups' overall survival, valve-related complications, and aortic valve function were compared. Results: The mean follow-up duration was $4.9{\pm}3.1$ years. After adjustment, the valve-sparing group had similar risks of death (hazard ratio [HR], 0.61; p=0.45), and valve related complications (HR, 1.27; p=0.66). However, a significant number of patients developed moderate to severe AR in the valve-sparing group at a mean of $4.4{\pm}2.5$ years of echocardiographic follow-up (p<0.001). Conclusion: Both the Bentall operation and aortic valve-sparing procedure showed comparable long-term clinical results in patients with advanced aortic regurgitation with aortic root dilatation. However, recurrent advanced aortic regurgitation was more frequently observed following valve-sparing procedures.

• Journal of Crop Science and Biotechnology
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• 제10권2호
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• pp.57-63
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• 2007

Due to the strong influence of nitrogen(N) on plant productivity, a vast amount of N fertilizers is used to maximize crop yield. Over-use of N fertilizers leads to severe pollution of the environment, especially the aquatic ecosystem, as well as reducing farmer's income. Growing of N-efficient cultivars is an important prerequisite for integrated nutrient management strategies in both low- and high-input agriculture. Taking maize as a sample crop, this paper reviews the response of plants to low N stress, the physiological processes which may control N-use efficiency in low-N input conditions, and the genetic and molecular biological aspects of N-use efficiency. Since the harvest index(HI) of modern cultivars is quite high, further improvement of these cultivars to adapt to low N soils should aim to increase their capacity to accumulate N at low N levels. To achieve this goal, establishment and maintenance of a large root system during the growth period may be essential. To reduce the cost of N and carbon for root growth, a strong response of lateral root growth to nitrate-rich patches may be desired. Furthermore, a large proportion of N accumulated in roots at early growth stages should be remobilized for grain growth in the late filling stage to increase N-utilization efficiency. Some QTLs and genes related to maize yield as well as root traits have been identified. However, their significance in improving maize NUE at low N inputs in the field need to be elucidated.

• The Plant Pathology Journal
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• 제36권3호
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• pp.244-254
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• 2020

Gom-chwi (Ligularia fischeri) is severely infected with Phytophthora drechsleri, the causal organism of Phytophthora root rot, an economically important crop disease that needs management throughout the cultivation period. In the present study, Phytophthora root rot was controlled by using bacterial isolates from rhizosphere soils collected from various plants and screened for antagonistic activity against P. drechsleri. A total of 172 bacterial strains were isolated, of which, 49 strains showed antagonistic activities by dual culture assay. In the seedling assay, six out of the 49 strains showed a predominant effect on suppressing P. drechsleri. Among the six strains, the ObRS-5 strain showed remarkable against P. drechsleri when treated with seed dipping or soil drenching. The ObRS-5 strain was identified as Enterobacter asburiae based on 16S ribosomal RNA gene sequences analysis. The bacterial cells of E. asburiae ObRS-5 significantly suppressed sporangium formation and zoospore germination in P. drechsleri by 87.4% and 66.7%, respectively. In addition, culture filtrate of E. asburiae ObRS-5 also significantly inhibited sporangium formation and zoospore germination by 97.0% and 67.6%, respectively. Soil drenched bacterial cells, filtrate, and culture solution of E. asburiae ObRS-5 effectively suppressed Phytophthora root rot by 63.2%, 57.9%, and 81.1%, respectively. Thus, E. asburiae ObRS-5 could be used as a potential agent for the biological control of Phytophthora root rot infecting gom-chwi.

• 한국잠사곤충학회지
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• 제22권1호
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• pp.52-58
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• 1980

20년생 낮추베기 개양서반의 뽕밭에서 휴간 1.8m을 7등분으로, 2주간 1.2m를 7등분으로 각각 분할하고, 표토로부터 10cm씩 40cm 깊이의 토양을 구분 채취하여 총 196점에 대한 뿌리와 토양화학성분포를 조사 분석한바 그 결과는 다음과 같다. 1. 뿌리의 분포는 그루주변으로 갈수록 증가하늘 반면 pH 유효인산, Ca, Mg등은 이와 대조적으로 휴간에서 높았다. 2. 주간의 뿌리 및 토양화학성(pH, 유효인산, K, Ca, Mg등)은 비교적 균일한 분포를 보였다. 3. 층위별 뿌리의 분포는 10~20cm부위에서 가장 높은데 비해 0~10cm부에서는 20~30, 30~40에서 보다도 낮으며 pH, 유효인산, Ca, Mg, K등은 0~10cm부위에서 가장 높으며 심층으로 갈수록 낮아서, 사실상 양분의 효율적인 흡수가 극대점에 이르지 못한 것으로 판단되었다.

• 한국안전학회지
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• 제36권5호
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• pp.43-51
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• 2021

Incident investigation is one of the most important processes among various other safety management methods to prevent industrial accidents. Finding the root causes of accidents, eliminating hazards, and improving safety are the most important purposes of investigating accidents. During the investigation process, root cause analysis (RCA) techniques are used to effectively identify RCA. Over the past few decades, over 30 RCA methods have been developed. These techniques are being widely used in some industries, such as the nuclear and aircraft industries; however, most of the RCA techniques require professional knowledge and special training, making it difficult for safety managers in their respective fields to understand and apply them. Therefore, managers of general industrial sites are rarely present at the scene of actual accident investigations, and they cannot contribute much to the purpose and effectiveness of these investigations. In this study, to address these issues, we developed an RCA technique to facilitate root cause investigation of accidents in real-world industrial sites. To develop new techniques, Systematic Cause Analysis Technique (SCAT), one of the RCA techniques, was used to investigate incidents in the enterprise over three years. We also utilized feature analysis and other papers from existing RCA techniques. To verify its effectiveness, the technique proposed was also applied to the accident case. The technique developed can easily identify and analyze the root cause of an accident and help industrial managers. It can also identify the root cause category where accidents are concentrated and use this data to establish guidelines for preventing future accidents and, thus, focus on prioritizing improvement initiatives.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.709-718
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• 2019

The international nuclear industry has undergone a lot of changes since the Fukushima, Chernobyl and TMI nuclear power plant accidents. However, there are still large and small component deficiencies at nuclear power plants in the world. There are many causes of electrical equipment defects. There are also factors that cause component failures due to human errors. This paper analyzed the root causes of failure and types of human error in 300 cases of electrical component failures. We analyzed the operating experience of electrical components by methods of root causes in K-HPES (Korean-version of Human Performance Enhancement System) and by methods of human error types in HuRAM+ (Human error-Related event root cause Analysis Method Plus). As a result of analysis, the most electrical component failures appeared as circuit breakers and emergency generators. The major causes of failure showed deterioration and contact failure of electrical components by human error of operations management. The causes of direct failure were due to aged components. Types of human error affecting the causes of electrical equipment failure are as follows. The human error type group I showed that errors of commission (EOC) were 97%, the human error type group II showed that slip/lapse errors were 74%, and the human error type group III showed that latent errors were 95%. This paper is meaningful in that we have approached the causes of electrical equipment failures from a comprehensive human error perspective and found a countermeasure against the root cause. This study will help human performance enhancement in nuclear power plants. However, this paper has done a lot of research on improving human performance in the maintenance field rather than in the design and construction stages. In the future, continuous research on types of human error and prevention measures in the design and construction sector will be required.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.806-813
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• 2005

시계열의 구조를 정확히 파악하기 위해서는 구조변화와 단위근의 존재여부를 가설 검정하는 것이 필요하다. 하지만, 이 두 가지의 가설들은 각각 검정되어 왔고, 이에 따라 단위근도 존재하고 구조변화도 존재하거나, 어느 하나만 존재하는 시계열들을 구분하여 파악하는 데에 있어서는 한계점이 있었다. 이 논문에서는 상태공간모형과 시뮬레이션 방법에 근거하여 두 가지 가설을 동시에 검정하는 절차를 제시하여 논란이 되는 시계열들에 대해 합리적인 해결책을 제시하고자 한다.

• International Journal of Quality Innovation
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• 제5권1호
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• pp.23-33
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• 2004

In Japan, where ISO14001 certifications have passed the 10,000 mark, the need for environmental management has taken firm root among companies. However, in the small-and medium-enterprise sector, and among tiny businesses, there are firms not obtaining ISO certification due to their concern about human resources and increased work load. On the other hand, among businesses that have already succeeded in gaining ISO certification. one does not sense any growth with regard to the continual improvement. Voices from certain quarters indicate there is a lack of incentive to keep on improving. With this background, we herewith present a new system to evaluate the level of environmental management in a company by means of a 5-step system.