• Journal of Chest Surgery
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• v.56 no.6
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• pp.387-393
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• 2023

Background: The aim of this study was to evaluate the clinical efficacy of a modified surgical procedure for the treatment of varicose veins. Methods: This retrospective analysis was conducted on lower extremities with symptomatic great saphenous vein (GSV) incompetence that underwent stripping from the groin to the knee, with preservation of the superficial epigastric vein (SEV), between January 2015 and April 2022. Follow-up assessments were performed using Doppler ultrasound, Venous Clinical Severity Score (VCSS), and the Aberdeen Varicose Vein Questionnaire (AVVQ) at 6 and 12 months after surgery. Results: The study included 179 limbs from 120 patients (47 men and 73 women). The mean patient age was 56.5 years (range, 20-78 years), and the distribution of preoperative Clinical-Etiology-Anatomy-Pathophysiology clinical classes was 8% C0-C1, 88% C2, and 4% C3-C6. The preoperative diameter of the saphenofemoral confluence averaged 6.9 mm (range, 2.7-15.8 mm). After a mean postoperative follow-up period of 24 months, evidence of neovascularization around the stump of the saphenofemoral junction (SFJ) was observed in 2 limbs (1.1%). Additionally, varicose vein recurrence was found in 1 limb (0.6%) and was associated with an incompetent thigh perforator. At postoperative follow-up, both VCSS and AVVQ scores were significantly lower than the preoperative scores. Conclusion: Modified surgical treatment of GSV incompetence, involving preservation of the SEV and stripping of a short segment up to the knee, demonstrated favorable clinical results in terms of postoperative complication rate, neovascularization rate around the SFJ stump, varicose vein recurrence rate, and improvement in lower extremity symptoms.

• Journal of The Korean Astronomical Society
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• v.56 no.1
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• pp.97-115
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• 2023

We present the deep homogeneous UBV RI photometric data of 135,071 stars down to V ~ 23 mag and I ~ 22 mag toward the Carina Nebula. These stars are cross-matched with those from the previous surveys in the X-ray, near-infrared, and mid-infrared wavelengths as well as the Gaia Early Data Release 3 (EDR3). This master catalog allows us to select reliable members and determine the fundamental parameters distance, size, stellar density of stellar clusters in this star-forming region. We revisit the reddening toward the nebula using the optical and the near-infrared colors of early-type stars. The foreground reddening [E(B-V)_fg] is determined to be 0.35 ± 0.02, and it seems to follow the standard reddening law. On the other hand, the total-to-selective extinction ratio of the intracluster medium (R_V,cl) decreases from the central region (Trumpler 14 and 16, R_V,cl ~ 4.5) to the northern region (Trumpler 15, R_V,cl ~ 3.4). It implies that the central region is more dusty than the northern region. We find that the distance modulus of the Carina Nebula to be 11.9 ± 0.3 mag (d = 2.4 ± 0.35 kpc) using a zero-age main-sequence fitting method, which is in good agreement with that derived from the Gaia EDR3 parallaxes. We also present the catalog of 3,331 pre-main-sequence (PMS) members and 14,974 PMS candidates down to V ~ 22 mag based on spectrophotometric properties of young stars at infrared, optical, and X-ray wavelengths. From the spatial distribution of PMS members and PMS candidates, we confirm that the member selection is very reliable down to faint stars. Our data will have a legacy value for follow-up studies with different scientific purposes.

• The Journal of Advanced Prosthodontics
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• v.16 no.2
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• pp.77-90
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• 2024

PURPOSE. The study aims to investigate the influence of the ferrule effect and types of posts on the stress distribution in three morphological types of the maxillary central incisor. MATERIALS AND METHODS. Nine models were created for 3 maxillary central incisor morphology types: "Fat" type - crown 12.5 mm, root 13 mm, and buccolingual cervical diameter 7.5 mm, "Medium" type - crown 11 mm, root 14 mm, and buccolingual cervical diameter 6.5 mm, and "Slim" type - crown 9.5 mm, root 15 mm, and buccolingual cervical diameter 5.5 mm. Each model received an anatomical castable post-and-core or glass-fiber post with resin composite core and three ferrule heights (nonexistent, 1 mm, and 2 mm). Then, a load of 14 N was applied at the cingulum with a 45° slope to the long axis of the tooth. The Maximum Principal Stress and the Minimum Principal Stress were calculated in the root dentin, crown, and core. RESULTS. Higher tensile and compression stress values were observed in root dentin using the metallic post compared to the fiber post, being higher in the slim type maxillary central incisor than in the medium and fat types. Concerning the three anatomical types of maxillary central incisors, the slim type without ferrule height in mm presented the highest tensile stress in the dentin, for both types of metal and fiber posts. CONCLUSION. Post system and tooth morphology were able to modify the biomechanical response of restored endodontically-treated incisors, showing the importance of personalized dental treatment for each case.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.2
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• pp.57-60
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• 2007

Interest in chum salmon(Oncorhynchus keta) biology I Korea has increased since the establishment of the Yangyang Inland Hatchery of the National Fisheries Research and Development Institute during mid 1980s. The enhancement program of chum salmon was expanded thereafter, so that chum salmon were transplanted 18 streams in the coast of the Korean Peninsula. However, ecological research on salmon species was very limited due to the lack of a research program. Though involvement in the North Pacific Anadromous Fish Commission (NPAFC) requires scientific investigation on salmon research of each member nation, no conspicuous increase in research funding was achieved in Korea. Oceanic environments have been rapidly altered by climate change during the last a few decades and ocean ecosystems including salmon populations will be modified by global warming. Special attention is needed for stocks near the southern boundary of distribution, such as Korean chum salmon. This special issue is the venue for reviewing ongoing researches in Korea, and we hope that this issue will be a big step toward active ecological research in Korea under changing environments.

• Structural Engineering and Mechanics
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• v.89 no.1
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• pp.1-11
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• 2024

This article introduces a novel analytical model for examining the impact of porosity on shear correction factors (SCFs) in functionally graded porous beams (FGPB). The study employs uneven and logarithmic-uneven modified porosity-dependent power-law functions, which are distributed throughout the thickness of the FGP beams. Additionally, a modified exponential-power law function is used to estimate the effective mechanical properties of functionally graded porous beams. The correction factor plays a crucial role in this analysis as it appears as a coefficient in the expression for the transverse shear stress resultant. It compensatesfor the assumption that the shear strain is uniform across the depth of the cross-section. By applying the energy equivalence principle, a general expression for static SCFs in FGPBs is derived. The resulting expression aligns with the findings obtained from Reissner's analysis, particularly when transitioning from the two-dimensional case (plate) to the one-dimensional case (beam). The article presents a convenient algebraic form of the solution and provides new case studies to demonstrate the practicality of the proposed formulation. Numerical results are also presented to illustrate the influence of porosity distribution on SCFs for different types of FGPBs. Furthermore, the article validates the numerical consistency of the mechanical property changesin FG beams without porosity and the SCF by comparing them with available results.

• Environmental and Resource Economics Review
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• v.33 no.1
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• pp.33-57
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• 2024

This study analyzes the purchase subsidy for electric light-duty vehicles in terms of environmental benefits and total cost of ownership(TCO). For the environmental benefits, we considered the emissions from the power generation mix and reflected the change in efficiency of electric vehicles according to the temperature distribution. The environmental benefits of driving electric vehicles were estimated to be between KRW 2.2 million and KRW 5.3 million. Also, the TCO of electric vehicles compared to diesel vehicles under the current purchase subsidy was estimated to be about KRW 3.6 million lower for business use and about KRW 6.6 million lower for non-business use. These results imply that it is reasonable to lower the unit price of the purchase subsidy even within the same budget. Moreover, the remaining budget could be better spent on upgrading the charging infrastructure, which would reduce the inconvenience of charging for potential buyers.

• Food Science and Preservation
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• v.31 no.2
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• pp.218-226
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• 2024

The oriental melon poses challenges in terms of long-term storage and distribution. Addressing these issues requires an extension of the storage life through appropriate processing. In this study, pretreated hot-air dried oriental melon slices (steamed and freeze-thawed) were prepared, and their physicochemical and organoleptic properties were examined. The control group (CON) consisted of hot-air dried oriental melon slices without pretreatment, while the steamed group (STG) and freeze-thawed group (FTG) consisted of hot-air dried oriental melon slices pretreated using steaming and freeze-thawing methods, respectively. The moisture contents detected in the CON, STG, and FTG groups ranged from 15.96% to 27.30%, with variations of 7.53 to 8.40 °Brix for the soluble solid contents. The CON group showed the highest Hunter color value for lightness (L^*) and the lowest value for redness (a^*). The texture profile analysis revealed the highest hardness and chewiness in the order of STG > CON > FTG. Considerable differences were observed in springiness and adhesiveness in the FTG group compared to the other groups. The organoleptic evaluation showed that the CON group had the highest sensory scores for overall preference. These findings indicate that the properties of hot-air dried oriental melon slices were influenced by physical pretreatments and that manufacturing these slices without pretreatment is the most effective method in terms of processing simplicity and cost efficiency.

• Information Systems Review
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• v.19 no.1
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• pp.25-48
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• 2017

As the number of Internet users has increased, the uses of social networking sites (SNSs) and online games have become universal activities across gender and ages. The extensive distribution and the usage of the Internet are beneficial to our society, but its adverse effects, such as Internet addiction, which refers to uncontrollable excessive Internet use, are becoming prevalent. Relevant social costs are also becoming troublesome. SNS and gaming addictions have negative effects on one's life, causing significant social problems. To illustrate different facets of these addictions, Problem Behavior Theory is adopted in the study. How self-esteem and perceived family environment affect SNS addiction and gaming addiction is addressed. The main subjects are Korean university students in their 20s who use SNS and play online games. The relationship between SNS addiction and gaming addiction is also addressed.

• Journal of the Korean Institute of Rural Architecture
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• v.26 no.2
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• pp.35-40
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• 2024

This study examines the classification and typical characteristics of 148 owner shop houses existing in the historical city center of Cheongju. First, they can be classified into single-story, middle-story, and divided types according to the distribution of residential and commercial functions. The single-story(36) has 'ㅡ', 'ㄱ', and 'narrow and deep'-shaped arrangement, with stores on the front and houses on the rear. The middle-story second floor(89) is divided into a first-story store and a second-story house, and the third floor(23) has different functions for each floor, but more than half of them have houses on the second and third floors. Among the total, there are also 16 cases in which the division type is taken with different construction times and structures. Second, in the position of the stairs connected to the upper floor among the middle-floor types(112), the outer stair type(52) to separate from the living space while making the most of the stores on the first floor accounts for 47%, but the biggest feature is that the inner staircase type(34) with privacy reaches 30%. The rear stair room type(26) entering through alleyways or private yards is also 23%. Third, the front pillar spacing varies from 1bay to 4bay in appearance, but the 2bay type on the 2nd floor and the 1bay type on the 3rd floor occupy the largest proportion. This exterior type is a characteristic of a owner shop house that can measure the range of personal ownership. Despite the conflicting functions of stores and houses, 35~40% of the cases are in which the opening positions of the upper and lower floors are unified.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.6
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• pp.17-31
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• 2023

An activity-based model requires detailed population information to model individual travel behavior in a disaggregated manner. The recent innovative approach developed deep generative models with novel regularization terms that improves fidelity and diversity for population synthesis. Since the method relies on measuring the distance between distribution boundaries of the sample data and the generated sample, it is crucial to obtain well-defined continuous representation from the discretized dataset. Therefore, we propose an improved entity embedding models to enhance the performance of the regularization terms, which indirectly supports the synthesis in terms of feasible and diverse populations. Our results show a 28.87% improvement in the F1 score compared to the baseline method.