• Journal of Life Science
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• v.33 no.10
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• pp.842-850
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• 2023

Pyrrolnitrin, pyrrolomycin, and pyoluteorin are functional halogenated phenylpyrrole derivatives (HPDs) derived from microorganisms with diverse antimicrobial activities. Pyrrolnitrin is a secondary metabolite produced from L-tryptophan through four-step reactions in Pseudomonas fluorescens, Burkholderia cepacia, Serratia plymuthica, etc. It is currently used for the treatment of superficial dermatophytic fungal infections, has high antagonistic activities against soil-borne and foliar fungal infections, and has many industrial applications. Since pyrrolnitrin is easily decomposed by light, it is difficult to widely use it outdoors. As an alternative, fludioxonil, a synthetically produced non-systemic surface fungicide that is structurally similar and has excellent light stability, has been commercialized for seed and foliar treatment of plants. However, due to its high toxicity to aquatic organisms and adverse effects in human cell lines, many countries have established maximum residue levels and strictly control its levels. Pyrrolomycin and pyoluteorin, which have antibiotic/antibiofilm activity against Gram-positive bacteria and high anti-oomycete activity against the plant pathogen Pythium ultimum, respectively, were isolated and identified from microorganisms. This review summarizes the biosynthesis and production of natural pyrrolnitrin derived from bacteria and the characteristics of synthetic fludioxonil and other natural phenylpyrrole derivatives among the HPDs. We expect that a plethora of highly effective, novel HPDs that are safe for humans and environments will be developed through the generation of an HPD library by microbial biosynthesis and chemical synthesis.

• Journal of Global Scholars of Marketing Science
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• v.18 no.1
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• pp.115-139
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• 2008

Since financial crisis of IMF resulted in intensive competitiveness and adverse management environment, many hotel industries have responded it with restructuring. Since this restructuring is accompanied by reduction of employees, hence comes the recognition of justice in the procedure of restructuring. When the surviving employees in the restructuring process recognize unfairness in the procedure and practical operations, organization effectiveness can not be maintained due to losing trust of their employers. In this paper I will examine the relationship between validity of restructuring and compensatory programs for layoffs and surviving employees' trust of the employers. Also I will find out the relationship between remaining employees' trust of the employers and their job satisfaction and organization commitment. Through this relationship, we can prepare an alternative to reduce negative effect of restructuring. The hypotheses of this study are proposed as follows: H1: The higher surviving employees' recognition of procedural justice in restructuring process is, the higher their trust with a manager of the company is. H2: The higher surviving employees' recognition of distributive justice in restructuring process is, the higher their trust with a manager of the company is. H3: The higher surviving employees' recognition of procedural justice in restructuring process is, the higher their job satisfaction is. H4: The higher surviving employees' recognition of distributive justice in restructuring process is, the higher their job satisfaction is. H5: The higher surviving employees' recognition of procedural justice in restructuring process is, the higher their organization commitment is. H6: The higher surviving employees' recognition of distributive justice in restructuring process is, the higher their organization commitment is. H7: The higher surviving employees' trust with a manager of the company in restructuring process is, the higher their job satisfaction is. H8: The higher surviving employees' trust with a manager of the company in restructuring process is, the higher their organization commitment is. For the purposes of this study, employees working in luxury hotels located in Seoul were targeted. Self-administered questionnaires were distributed to those who consented with the investigation after explaining the purpose of the survey. A total of 500 questionnaires were distributed and 450 questionnaire were returned to the researcher for analysis. 430 of the returned questionnaires were used for analysis. As for the education for this survey, 250 junior college graduates or under (58.1%), 143 college graduates (33.3%) and 37 graduate school graduates (8.6%). As for the marital status, 315 persons (73.3%) are single and 115 are married (26.7%). As for the monthly income, 49 people (11.48%) are less than 2 million won, 148 (34.4%) are between 2 million and less than 2.5 million won, 153 (35.6%) are between 2.5 million to less than 3 million won, 80 (18.6%) are more than 3 million won. As for the workplace, 293 people (68.1%) work for the F&B department, 73 (17.0%) for rooms department, 41 (9.5%) for operation/ marketing department, 23 (5.3%) for account/ general affair department. As for the period of employment, 85 people (19.8%) are less than 5 years, 150 (34.9%) are between 6 to 9 years, 143 (33.3%) are between 10 to 14 years. and 52 (3.%) are more than 15 years. An exploratory factor analysis was used to survey validity and reliability of calculating tool on perceived values. This study used correlation between individual items and whole items and Cronbach's alpha value of multiple-item scale which is usually used to assess scale and reliability. Reliability of conceptual sub-dimension was assessed by basing on repeated procedure of correlation between individual items and whole items and factor loading. 1. Verification of correlation between validity of restructuring and trust This research showed that procedural and distributive justice of restructuring affects trust positively. The path coefficient between procedural justice of restructuring and trust is 0.719(t=10.135, p=0.000), and thereby the higher procedural justice results in higher trust. The path coefficient between distributive justice of restructuring and trust is 0.160(t=3.291, p=0.001), and thereby the higher distributive justice results in higher trust. Hence H1 and H2 are accepted. 2. Verification of correlation between validity of restructuring and job satisfaction The path coefficient between procedural justice of restructuring and job satisfaction is 0.179(t=2.202, p=0.028), and thereby the higher procedural justice results in higher job satisfaction. The path coefficient between distributive justice of restructuring and job satisfaction is 0.074(t=1.620, p=0.105), and thereby distributive justice of restructuring has no relationship with job satisfaction. Hence H3 is accepted, but H4 is removed. 3. Verification of correlation between validity of restructuring and organization commitment The path coefficient between procedural justice of restructuring and organization commitment is 0.188(t=2.466, p=0.014), and thereby the higher procedural justice results in higher organization commitment. The path coefficient between distributive justice of restructuring and organization commitment is 0.118(t=2.720, p=0.007), and thereby the higher distributive justice results in higher organization commitment. Hence H5 and H6 are accepted. 4. Verification of correlation between trust and job satisfaction The path coefficient between trust and job satisfaction is 0.610(t=6.736, p=0.000), and thereby the correlation has a meaningful result. Since the higher trust of the employer results in higher job satisfaction, H7 is accepted. 5. Verification of correlation between trust and organization commitment The path coefficient between procedural justice of restructuring and job satisfaction is 0.446(t=5.547 p=0.000), and thereby the higher trust of the employer results in higher organization commitment. Hence H8 is accepted. This research aimed to help the employers of hotel industries by analyzing the effects of validity of restructuring on employees' trust, job satisfaction and organization commitment. The research found that employer's validity of restructuring has significant affects on the degree of employee's trust with a manager, thereby reducing the negative effects of restructuring and enhancing organization commitment and job satisfaction. The principal purpose of this research is to confirm the correlation between employees' perceived validity of restructuring and their trust with a manager. Also whether this correlation results in competitive edge of the company is also investigated. It is also pointed out that employees had to participated the procedure of restructuring, sharing the philosophy and reason of restructuring. This participation and furthermore compensatory methods can reduce employees' anxiety of organization operations. Variable of trust appeared to have impact on intermediation effect between perceived variable of validity and job satisfaction, organization commitment, so that increase of trust with a manager plays an crucial role in increasing organization effectiveness. Since this research did not cover whole hotel industries which underwent restructuring, it showed a limit. Unlike previous studies which dealt with validity and trust of superior bosses, this research focussed on employers. Also the organization citizenship which is not considered in this study will be dealt with in the future study.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.200-211
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• 2022

The celadon stools with an openwork ring design which consist of four items as one collection were excavated from Gaeseong, Gyeonggi-do Province. The celadon stools were designated and managed as treasures due to their high arthistorical value in the form of demonstrating the excellence of celadon manufacturing techniques and the fanciful lifestyles during the Goryeo Dynasty. However, one of the items, which appeared to have been repaired and restored in the past, suffered a decline in aesthetic value due to the aging of the treatment materials and the lack of skill on the part of the conservator, raising the need for re-treatment as a result of structural instability. An examination of the conservation condition prior to conservation treatment found structural vulnerabilities because physical damage had been artificially inflicted throughout the area that was rendered defective at the time of manufacturing. The bonded surfaces for the cracked areas and detached fragments did not fit, and these areas and fragments had deteriorated because the adhesive trickled down onto the celadon surface or secondary contaminants, such as dust, were on the adhesive surface. The study identified the position, scope, and conditions of the bonded areas at the cracks UV rays and microscopy in order to investigate the condition of repair and restoration. By conducting Fourier-transform infrared spectroscopy(FT-IR) and portable x-ray fluorescence spectroscopy on the materials used for the former conservation treatment, the study confirmed the use of cellulose resins and epoxy resins as adhesives. Furthermore, the analysis revealed the addition of gypsum(CaSO₄·2H₂O) and bone meal(Ca₁₀ (PO₄)₆(OH)₂) to the adhesive to increase the bonding strength of some of the bonded areas that sustained force. Based on the results of the investigation, the conservation treatment for the artifact would focus on completely dismantling the existing bonded areas and then consolidating vulnerable areas through bonding and restoration. After removing and dismantling the prior adhesive used, the celadon stool was separated into 6 large fragments including the top and bottom, the curved legs, and some of the ring design. After dismantling, the remaining adhesive and contaminants were chemically and physically removed, and a steam cleaner was used to clean the fractured surfaces to increase the bonding efficacy of the re-bonding. The bonding of the artifact involved applying the adhesive differently depending on the bonding area and size. The cyanoacrylate resin Loctite 401 was used on the bonding area that held the positions of the fragments, while the acrylic resin Paraloid B-72 20%(in xylene) was treated on cross sections for reversibility in the areas that provided structural stability before bonding the fragments using the epoxy resin Epo-tek 301-2. For areas that would sustain force, as in the top and bottom, kaolin was added to Epo-tek 301-2 in order to reinforce the bonding strength. For the missing parts of the ring design where a continuous pattern could be assumed, a frame was made using SN-sheets, and the ring design was then modeled and restored by connecting the damaged cross section with Wood epos. Other restoration areas that occurred during bonding were treated by being filled with Wood epos for aesthetic and structural stabilization. Restored and filled areas were color-matched to avoid the feeling of disharmony from differences of texture in case of exhibitions in the future. The investigation and treatment process involving a variety of scientific technology was systematically documented so as to be utilized as basic data for the conservation and maintenance.

• Korean Journal of Crystallography
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• v.3 no.1
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• pp.9-22
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• 1992

Two crystal structures of bromine sorption complexes of vacuum dehydrated Cd(ll)-exchanged zeolite A have been determined by single-crystal xray diffraction techniques in the cubic space group Pm3m at 21(1) ℃. Both crystals were ion exchanged in flowing streams of exchange solution In which mole ratio of Cd(NO3)2 and Cd(OOCCH3)B was 1:1 with a total concentration of 0.05 M. First crystal was dehydrated at 450℃ and 2 ×10-6 Torr for two days. Second crystal was dehydrated at 650℃ and 2 ×10-6 Torr for two days. Both crystals were then treated with 160 Torr for two days. Second crystal was dehydrated at 650℃ and 2 × 10-6 Torr for two days. Both crystals were then treated with 160 Torr of zeolitically dried bromine vapor at 24℃. Full-matrix least-squares refinements of toe first crystal(a: 12.250(1) A )· and the second crystal(a: 12.204(2) A ) have contecoed to final error indices, Rl:0.075 and Ra:0.079 with 212 reflections, and Rl : 0.089 and Ra = 0.078 with 128 reflections, respectively, for which I >3σ(I). Crystallographic analyses of both crystals show that six Cd2+ ions are located on two different threefold axes of unit cell associated with 6-ring oxygens. Each 4.5 Cd2+ ion is recessed ca.0. 441 A Into the large cavity to complex either with Brsor with Br3from the (111) plane of 0(3), whereas each 1.5 Cd2+ ions recessed ca. 0.678 A into we sodalite unit. Approximately 1.5 Br5-and 1.5 Br3-ions are sorbed per unit cell. Each Brsion interacts and stabilized by complexing with two Cd2+ ions and framework oxide ions, while each Br3ion interacts with one Cd2+ ion and framework oxide ions. Because of residual water molecules the following reactions may be occurred inside of zeolite cavity:

• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.1-11
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• 2009

Fine-grained peridotite xenoliths are rarely trapped in the basaltic rocks from the southeastern part of Jeju Island. Based on textural characteristics of the constituent phases showing uniform-sized, fine-grained tabular to mosaic grains with rare porphyroclastic relics, the studied samples can be defined as fine-grained, foliated porphyroclastic peridotites (FPP). Almost no significant difference among the FPPs in textures and major element compositions implies that the FPPs were derived from a structural domain, experiencing similar deformation events and deformation patterns. Moreover, the bimodal distribution with kink-banded porphyroclasts ($2{\sim}3mm$) and stain-free neoblasts ($200{\sim}300{\mu}m$), straight to gently curved grain boundaries with triple junctions, interstitial melt pockets, and microstructures for migrating grain boundary suggest that the studied samples went through dynamic recrystallization (${\pm}$ static recrystallization) in the presence of melt/fluid movement along foliation planes. No notable difference between the FPP and common protogranular xenoliths in major element compositions and geochemical evolution also implies that the FPP and protogranular xenoliths were from a similar horizon. Thus, the textural and geochemical characteristics of the FPPs reflects deformation events occurred at a localized and narrow zone within the lithospheric mantle beneath the Jeju Island. Although further detailed studies are necessary to define deformation events, the most possible process which could trigger deformation in the FPP in the rigid upper mantle was the ascending basaltic magma forming high-stress deformation zones. The suggested high-stress deformation zones in the lithosphere beneath the Jeju Island may be produced by paleo-faulting events related to the ascent of basalt magma before Jeju Island was formed.

• Journal of the Korean Magnetics Society
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• v.17 no.2
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• pp.81-85
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• 2007

MnTe layers of high crystalline quality were successfully grown on Si(100) : B and Si(111) substrates by molecular beam epitaxy (MBE). Under tellurium-rich condition and the substrate temperature around $400^{\circ}C$, a layer thickness of $700{\AA}$ could be easily obtained with the growth rate of $1.1 {\AA}/s$. We investigated the structural, magnetic and transport properties of MnTe layers by using x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, and physical properties measurement system (PPMS). Characterization of MnTe layers on Si(100) : B and Si(111) substrates by XRD revealed a hexagonal structure of polycrystals with lattice parameters, ${\alpha}=4.143{\pm}0.001{\AA}\;and\;c=6.707{\pm}0.001{\AA}$. Investigation of magnetic and transport properties of MnTe films showed anomalies unlike antiferromagnetic powder MnTe. The temperature dependence of the magnetization data taken in zero-field-tooling (ZFC) and field-cooling (FC) conditions indicates three magnetic transitions at around 21, 49, and 210 K as well as the great irreversibility between ZFC and FC magnetization in the films. These anomalies are attributable to a magnetic-elastic coupling in the films. Magnetization measurements indicate ferromagnetic behaviour with hysteresis loops at 5 and 300 K for MnTe polycrystalline film. The coercivity ($H_c$) values at 5 and 300 K are 55 and 44 Oe, respectively. In electro-transport measurements, the temperature dependence of resistivity revealed a noticeable semiconducting behaviours and showed conduction via Mott variable range hopping at low temperatures.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.133-146
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• 2001

We report the results of structural field observation and measurement of anisotropy of magnetic susceptibility (AMS) of the diamictitic Hwanggangri Formation distributed in Chungju-Suanbo area of the Okchon Belt, Korea. The outcrops of the Hwanggangri Formation show two types of cleavage in general: slaty cleavage (SI) and crenulation cleavage (5z). 5] cleavage is, however, well observable only in the notheastem (NE) part of study area, while overwhelmed by 52 cleavage in the southwestern (5W) part, indicating stronger later deformation in 5W part of the study area. This partitioning of the study area is corroborated by both IRM and AMS parameters: NE part of the study area is characterized by higher IRM intensity, higher bulk magnetic susceptibility, higher AM5 degree, and by oblate shape of magnetic susceptibility ellipsoid. Their values become drastically lowered toward southwest, and reach to a stable minimum in the whole 5W part of the study area. In addition, degree of both metamorphism and deformation tends to increase gradually from northeast toward southwest and also from northwest toward southeast in the study area. Based on the distribution pattern of the principal axes ( $k_1, k_2, k_3$ axes) of magnetic anisotropy ellipsoids revealed in the NE part of the study area, three episodes of deformation ( $D_1, D_2, D_3$ ) are recognized: D_1$ deformation produced $S_2$ cleavage with NE-5W trend, which is caused by a strong NW-SE tlattening of a coaxial pure shear. $D_2$ deformation produced 5z cleavage characterized by a non-coaxial deformation. It was caused by a ductile or semi-ductile thrusting toward NW and concurrent sinistral shearing along $S_2$ cleavage plane. Lastly, $D_3$ deformation produced tlexural folding of all previous structures with a nearly horizontal NE fold axis. Distribution pattern of the principal axes of magnetic anisotropy ellipsoid from the SW part of the study area, on the other hand, does not show any coherency among sites or samples. We interpret that this dispersed pattern of $k_1, k_2, k_3$ axes together with lower anisotropy strength indicates that magnetic fabrics in the SW part have been disturbed either by a superposition of strong deformation/metamorphism or by a kind of reciprocal strain due to an overlapping of $D_1$ and $D_2$ or by both processes.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.101-109
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• 2013

Purpose: Pediatric urolithiasis is uncommon in children but is a cause of significant morbidity and damage to the kidney. Although much information on adult urolithiasis is available in the literature, large studies on the pediatric population are still scarce. In this report, we review our experience with pediatric urolithiasis over 22 years at a tertiary referral center. Method: We retrospectively reviewed the records of children with newly diagnosed urolithiasis between January 1991 and May 2013. We assessed the age, sex, family history, initial symptoms, location of stones, underlying cause, stone analysis, treatment, and recurrence among the patients. Results: In total, 137 patients (96 male, 41 female) were assessed. The age range was 0-17 years (mean age, 6.0 years). Forty-three (31%) children were aged <1 year, and 37% (16/43) had a history of intensive care unit (ICU) admission. Thirteen patients (9.5%) had a family history of stones. The most common symptoms at presentation among the patients were gross hematuria (56/137, 41%) and flank or abdominal pain (46/137, 34%). The stones were located in the kidney (85/137, 62%), ureter (29/137, 21%), bladder (2/137, 1.4%), and multiple locations (20/137, 15 %). Congenital abnormalities of the genitourinary (G-U) tract, with or without metabolic abnormality, or urinary tract infection (UTI) was detected in 26 children (19%). Ninety-one patients (66%) underwent metabolic examination, and 38% of these patients exhibited an abnormality. UTI, with or without abnormalities of the G-U tract, or metabolic abnormality was detected in 26 children (19%). Of the 35 stones analyzed, the majority were calcium stones (20/35, 57%), followed by infected stones (5/35, 14%), uric acid stones (4/35, 11%), carbonate apatite stones (3/35, 7%), cystine stones (2/35, 6%), and phosphate stones (1/35, 3%). Five patients (4%) required open procedures, with or without non-open procedures, whereas 77 patients (56%) were managed conservatively; the remaining 55 patients (40%) received some other form of intervention. Eighteen patients (13%) had stone recurrence during the follow-up period. Conclusions: Pediatric urolithiasis is commonly associated with abnormalities of the G-U tract and/or metabolic disorders and/or UTI. Half of the patients will pass their stones spontaneously, and all the techniques of minimally invasive surgery are applicable in the treatment of children with stones. As the recurrence rates are high among this population, long-term follow-up is recommended and the complete clearance of stones is important.

• Composites Research
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• v.34 no.4
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• pp.241-248
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• 2021

As the electric vehicle market grows, there is an issue of light weight vehicles to increase battery efficiency. Therefore, it is going to replace the battery module cover that protects the battery module of electric vehicles with high strength/high heat-resistant polymer composite material which has lighter weight from existing aluminum materials. It also aims to respond to the early electric vehicle market where technology changes quickly by combining 3D printing technology that is advantageous for small production of multiple varieties without restrictions on complex shapes. Based on the composite material mechanics, the critical length of glass fibers in short glass fiber (GF)/polycarbonate (PC) composite materials manufactured through extruder was derived as 453.87 ㎛, and the side feeding method was adopted to improve the residual fiber length from 365.87 ㎛ and to increase a dispersibility. Thus, the optimal properties of tensile strength 135 MPa and Young's modulus 7.8 MPa were implemented as GF/PC composite materials containing 30 wt% of GF. In addition, the filament extrusion conditions (temperature, extrusion speed) were optimized to meet the commercial filament specification of 1.75 mm thickness and 0.05 mm standard deviation. Through manufactured filaments, 3D printing process conditions (temperature, printing speed) were optimized by multi-optimization that minimize porosity, maximize tensile strength, and printing speed to increase the productivity. Through this procedure, tensile strength and elastic modulus were improved 11%, 56% respectively. Also, by post-processing, tensile strength and Young's modulus were improved 5%, 18% respectively. Lastly, using the FEA (finite element analysis) technique, the structure of the battery module cover was optimized to meet the mechanical shock test criteria of the electric vehicle battery module cover (ISO-12405), and it is satisfied the battery cover mechanical shock test while achieving 37% lighter weight compared to aluminum battery module cover. Based on this research, it is expected that 3D printing technology of polymer composite materials can be used in various fields in the future.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.5
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• pp.25-33
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• 2011

This work proposes a skinny-type 10b 50MS/s 0.13um CMOS three-step pipeline ADC for CIS applications. Analog circuits for CIS applications commonly employ a high supply voltage to acquire a sufficiently acceptable dynamic range, while digital circuits use a low supply voltage to minimize power consumption. The proposed ADC converts analog signals in a wide-swing range to low voltage-based digital data using both of the two supply voltages. An op-amp sharing technique employed in residue amplifiers properly controls currents depending on the amplification mode of each pipeline stage, optimizes the performance of op-amps, and improves the power efficiency. In three FLASH ADCs, the number of input stages are reduced in half by the interpolation technique while each comparator consists of only a latch with low kick-back noise based on pull-down switches to separate the input nodes and output nodes. Reference circuits achieve a required settling time only with on-chip low-power drivers and digital correction logic has two kinds of level shifter depending on signal-voltage levels to be processed. The prototype ADC in a 0.13um CMOS to support 0.35um thick-gate-oxide transistors demonstrates the measured DNL and INL within 0.42LSB and 1.19LSB, respectively. The ADC shows a maximum SNDR of 55.4dB and a maximum SFDR of 68.7dB at 50MS/s, respectively. The ADC with an active die area of 0.53$mm^2$ consumes 15.6mW at 50MS/s with an analog voltage of 2.0V and two digital voltages of 2.8V ($=D_H$) and 1.2V ($=D_L$).