• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.3
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• pp.140-152
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• 2017

The Korea Meteorological Administration (KMA) regularly publishes various drought indices. However, most of these are meteorological drought indices that are not only difficult but often inappropriate to apply to agriculture. In this study, the meteorological drought index and the agricultural drought index were calculated for the representative points of South Korea during the same period, and the differences in geographical distribution were analyzed according to the characteristics of drought. Although the overall drought patterns estimated by multiple drought indices were similar, the differences were also confirmed due to the different simulation methods depending on the character of drought. Especially, agricultural drought index (ADI) showed higher accuracy in the agricultural sector than that of meteorological drought index (e.g., SPI, PN). In addition, the drought patterns in recent years analyzed by ADI were more severe in spring and early summer compared with normal year. In autumn and winter, drought was weaker than normal year. For the recent periods, inland areas had more droughts than coastal areas. Considering the specific drought indices for the individual sectors, it will be helpful to take measures against drought according to the individual characteristics.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.5
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• pp.299-304
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• 2017

Objectives: To test the feasibility of submandibular salivary gland (SMG) replantation techniques and the survival of the replanted glands. Such a study can provide a rationale for later allotransplantation procedures, along with implementation of conventional and advanced immunosuppression therapy. Materials and Methods: Six SMG replantations were performed in New Zealand white rabbits. One week postoperatively, $^{99m}Tc$ scintigraphy was performed and the uptake ratio and salivary excretion fraction were calculated. Two to four weeks later, submandibular glands were excised, fixed, and stained with H&E for histomorphometric evaluation. Results: Intraoperatively, all glands showed patent blood perfusion except gland 5. Positive tracer uptake and saliva excretion were documented by scintigraphy. On excision, all of the glands except glands 4 and 5 looked viable, with a red color and patent pedicles. Gland 4 was infected and filled with creamy pus, while gland 5 looked pale and necrotic. Histologically, glands 1, 2, 3, and 6 had preserved normal glandular tissue with slight variations from the contralateral normal glands, as their parenchyma was composed of mildly atrophic acini. Conclusion: Four out of six replanted SMGs successfully survived. The glands maintained good viability and function. Such success depends on safe harvesting, short anastomosis time, and strict control of infection.

• The Korean Journal of Applied Statistics
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• v.29 no.7
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• pp.1311-1327
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• 2016

We propose a multi-state model for analyzing semi-competing risks data with interval-censored or missing intermediate events. This model is an extension of the 'illness-death model', which composes three states, such as 'healthy', 'diseased', and 'dead'. The state of 'diseased' can be considered as an intermediate event. Two more states are added into the illness-death model to describe missing events caused by a loss of follow-up before the end of the study. One of them is a state of 'LTF', representing a lost-to-follow-up, and the other is an unobservable state that represents the intermediate event experienced after LTF occurred. Given covariates, we employ the Cox proportional hazards model with a normal frailty and construct a full likelihood to estimate transition intensities between states in the multi-state model. Marginalization of the full likelihood is completed using the adaptive Gaussian quadrature, and the optimal solution of the regression parameters is achieved through the iterative Newton-Raphson algorithm. Simulation studies are carried out to investigate the finite-sample performance of the proposed estimation procedure in terms of the empirical coverage probability of the true regression parameter. Our proposed method is also illustrated with the dataset adapted from Helmer et al. (2001).

• Smart Structures and Systems
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• v.15 no.2
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• pp.447-468
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• 2015

Modal identification of civil engineering structures based on ambient vibration measurement has been widely investigated in the past decades, and a variety of output-only operational modal identification methods have been proposed. However, vibration modes, even fundamental low-order modes, are not always identifiable for large-scale structures under ambient vibration excitation. The identifiability of vibration modes, deficiency in modal identification, and criteria to evaluate robustness of the identified modes when applying output-only modal identification techniques to ambient vibration responses were scarcely studied. In this study, the mode identifiability of the cable-stayed Ting Kau Bridge using ambient vibration measurements and the influence of the excitation intensity on the deficiency and robustness in modal identification are investigated with long-term monitoring data of acceleration responses acquired from the bridge under different excitation conditions. It is observed that a few low-order modes, including the second global mode, are not identifiable by common output-only modal identification algorithms under normal ambient excitations due to traffic and monsoon. The deficient modes can be activated and identified only when the excitation intensity attains a certain level (e.g., during strong typhoons). The reason why a few low-order modes fail to be reliably identified under weak ambient vibration excitations and the relation between the mode identifiability and the excitation intensity are addressed through comparing the frequency-domain responses under normal ambient vibration excitations and under typhoon excitations and analyzing the wind speeds corresponding to different response data samples used in modal identification. The threshold value of wind speed (generalized excitation intensity) that makes the deficient modes identifiable is determined.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.3
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• pp.61-69
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• 2015

This study presents a probabilistic knowledge discovery method to interpret heart rate variability (HRV) based on time and frequency domain indexes, extracted using discrete wavelet transform. The knowledge induction algorithm was composed of two phases: rule generation and rule estimation. Firstly, a rule generation converts numerical attributes to intervals using ROC curve analysis and constructs a reduced ruleset by comparing consistency degree between attribute-value pairs with different decision values. Then, we estimated three measures such as rule support, confidence, and coverage to a probabilistic interpretation for each rule. To show the effectiveness of proposed model, we evaluated the statistical discriminant power of five rules (3 for atrial fibrillation, 1 for normal sinus rhythm, and 1 for both atrial fibrillation and normal sinus rhythm) generated using a data (n=58) collected from 1 channel wireless holter electrocardiogram (ECG), i.e., HeartCall$^{(R)}$, U-Heart Inc. The experimental result showed the performance of approximately 0.93 (93%) in terms of accuracy, sensitivity, specificity, and AUC measures, respectively.

• Korean Journal of Medicinal Crop Science
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• v.17 no.5
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• pp.321-327
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• 2009

Sunlight, and in particular its UV component, is the major environmental trigger that underlies the major signs of human skin and skin cancer in general. Therefore, this study was carried out to investigate the UV protection effects of R. coreanus. R. coreanus was extracted by ultra high pressure extraction process at 500 MPa and $30^{\circ}C$ for 5 and 15 minutes. The cytotoxicity of the extracts extracted by ultra high pressure process on human dermal fibroblast cell CCD-986sk, human kidney normal cell HEK293, and human lung normal cell HEL299 was measured as 17.5%, 16.5% and 14.0%, respectively in adding $1.0\;mg/m{\ell}$ of the samples, which was much lower than that from conventional water extraction method at $100^{\circ}C$ as 23.2%, 22.5%, 21.2%. The secretion of $NO^-$ from macrophage showed $15.9\;{\mu}M$ on the R. coreanus extract from this process, which was higher than others. Prostaglandin $E_2$ ($PGE_2$) production from UV-induced human skin cells was also greatly decreased down to $510\;pg/m{\ell}$, compared to the control. From the results, we considered that the extracts from R. coreanus could be potent natural materials for skin anti-inflammation agent, and could be used as a potential anti-aging for the photo-damaged skin.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.11 no.1
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• pp.146-156
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• 2007

1. The effect of variations in inspiration and expiration times on heart rate variability was studied in 78 healthy subjects (mean age $24.35{\pm}1.92$ years; 47 male) between regulated respiration group and normal respiration group as the control group. 2. The control group followed normal respiration pattern, whereas the regulated group followed three types of respiration pattern. The first pattern was long respiration(E/I ratio 1.6:1), the second pattern was short inspiration followed by long expiration (SILE), and the last pattern was long inspiration followed by short expiration(LISE). The average expiration/inspiration time ratios of SILE and LISE were 1.0 and 3.4, respectively. The respiration rate in the regulated group was approximately 10 cycles/min. 3. Respiration rate and tidal volume are respiratory variables known to modulate RSA. The results of the present study indicate that RSA can also be modulated by a third respiratory variable, the expiration/inspiratory time ratio. In this study, LF, HF, RSA, VLF is increased the most in LISE group compared to the other groups. HF and RSA increased significantly in the long respiration rate and SILE groups. However LF and VLF, which reflects the sympathetic tones, did not increase as much as the LISE group.

• Applied Microscopy
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• v.20 no.1
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• pp.51-64
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• 1990

This experiment was performed to study the morphological changes of the goblet cells in the rabbit duodenal mucosa after common bile duct ligation. Healthy adult rabbits weighting about 2kg body weight were divided to normal and bile duct ligated groups. Common bile duct ligation was performed under ether anesthesia. Experimental animals were sacrificed on the 1st, 3rd, 5th, 7th and 14th day after the operation. Mucosal specimens from the upper part of duodenum were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde, followed by 1% osmium tetroxide, embedded in araldite mixture, cut with LKB-V ultratome, stained with uranyl acetate - lead citrate, and observed with JEM 100 CX II electron microscope. Observed results were as follow : 1. In the early stages(1st-5th day) of the experiments, the goblet cells showed apocrine and merocrine secretion. But those of the late stage(7th and 14th day) groups showed exocytotic merocrine secretion. 2. In the late stage of the experiments, there found than increase of newly formed goblet cells that contain electron lucent cytoplasms. 3. In the goblet cells of normal rabbit, mucous granules with higher or lower electron densities are found together in the cytoplasm, and electron lucent mucous granules occasionally fused together. But in the early stage of the common bile duct ligation, goblet cells contained granules of higher electron densities. 4. Considering the above findings, common bile duct ligation probably initiates the hypersecretion of mucous granules of goblet cells in the early stage, and may facilitate the differentiation of goblet cells in the later stage.

• Food Science of Animal Resources
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• v.34 no.1
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• pp.88-98
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• 2014

Total spleen lymphocytes, lymphocyte proliferation, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and interleukin-10 (IL-10) in spleen lymphocyte culture were studied in malnourished Wistar rats fed with goat milk yoghurt. Malnourished rats were created by using standard feed restriction as much as 50% of normal rats for 21 d. Goat milk yoghurt containing three types of microorganism e.g., Lactobacillus acidophilus, Sterptococcus thermophilus and Bifidobacterium longum derived from Lacto-B culture in powder form. After 21 d, the rats continued to receive restricted feeding and supplemented with goat milk yoghurt for 7 d. Total splenocytes were counted by hemocytometer. Splenocytes proliferation was expressed as stimulation index, whereas the TNF-${\alpha}$ and IL-10 of spleen lymphocyte culture were measured by ELISA technique. The total number of splenocytes and stimulation index of splenocytes in moderate malnourished and normal rats supplemented with goat milk yoghurt was not significantly different. The level of TNF-${\alpha}$ in the rat supplemented with goat milk yoghurt was lower (p<0.05) than the control group, whereas the level of IL-10 in the rat supplemented with goat milk yoghurt was higher (p<0.05) than the control group. In conclusion, goat milk yoghurt supplementation in malnourished rats could decrease TNF-${\alpha}$ as a representation of the pro-inflammatory cytokine, while it increases IL-10 as a representation of the anti-inflammatory cytokine.

• BMB Reports
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• v.36 no.1
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• pp.78-81
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• 2003

The prevention of cancer is one of the most important public health and medical practices of the $21^{st}$ century. We have made much progress in this new emerging field, but so much remains to be accomplished before widespread use and practice become common place. Cancer chemoprevention encompasses the concepts of inhibition, reversal, and retardation of the cancer process. This process, called carcinogenesis, requires 20-40 years to reach the endpoint called invasive cancer. It typically follows multiple, diverse and complex pathways in a stochastic process of clonal evolution. These pathways appear amenable to inhibition, reversal or retardation at various points. We must therefore identify key pathways in the evolution of the cancer cell that can be exploited to prevent this carcinogenesis process. Basic research is identifying many genetic lesions and epigenetic processes associated with the progression of precancer to invasive disease. Many of these early precancerous lesions favor cell division over quiescence and protect cells against apoptosis when signals are present. Many oncogenes are active during early development and are reactivated in adulthood by aberrant gene promoting errors. Normal regulatory genes are mutated, making them insensitive to normal regulatory signals. Tumor suppressor genes are deleted or mutated rendering them inactive. Thus there is a wide range of defects in cellular machinery which can lead to evolution of the cancer phenotype. Mistakes may not have to appear in a certain order for cells to progress along the cancer pathway. To conquer this diverse disease, we must attack multiple key pathways at once for a predetermined period of time. Thus, agent combination prevention strategies are essential to decrease cancer morbidity. Furthermore, each cancer type may require custom combination of prevention strategies to be successful.